摘要:

THE JOURNAL OF THE CHEMICAL SOCIETY OF LONDON. afimmittee XrP @zrlYkrrtian F. A. ABEL F.R.S. J H. GLADSTONE PH,D, F,R.S, E,FRANKLAND PH.D. F.R.S. 1 W.A. MlLLER MJ. F.R,S. &bitfir HENRY WATTS B.A. F.R.S. NEW SERIES,VOL.VII. (Entire Series VoI. XXII.) LONDON VAN VOORST 1 PATERNOSTER ROW. 1869. LONDON HARRISON AND SONS PRINTERS IN ORDINARY TO HEB MAJESTY ST. MARTIN’S LANE. CONTENTS TO THE TWENTY-SECOND VOLUME. PAGE On the Isolation of the Missing Siilphur Urea. By J. Emerson Reynolds Member of the Royal College of Physicians Edinburgh ; Keeper of the Minerals and Analyst to the Royal Dublin SocietF &c.. .. . . . . ...... . .. 1 On some Compounds of Phosphorus containing Nitrogen. By J. H. Glad-stone,Ph.D.,F.R.S......................... ...................-15 Mineralogical Notices. By A. H. ChuYch . . .... . ...... . . . ....... . .... 22 Note on the Action of Chloride of Lime on hiline. By W. 3. Perkin F.R.S. ..,...,. .. ........ .. .. ..,............................. .. 25 Researches on Acids of the Lactic Series. No. I. Synthesis of Acids of the Lactic Series. By E. Frankland F.R.S. Professor of Chemistry in the Government School of Mines ; and B. F. Duppa Bsq.. ...... . ..... . .. 28 On the connection between the Mechanical Qualities of Malleable Iron and Steel and the amount of Phosphorus they contain. By B. H. Paul Ph.D ..... ........ .... .. , .................... ...... ............ 81 On the Chemical Compositionof Canauba Wax. By NevilStory-Maskelyne,M.A.............................. ............................. 87 On the Chemistry of Sugar Refining. By Dr. Wallace F.R.S.E. Glasgow . 100 On Catharism or the Influence of Chemically Clean Surfaces. By Charles Tomlinson F.R.S. F.C.S. ................ ...................... 125 On the Butyl Compounds derived from the Butylic Alcohol of Fermentation. By Ernest T. Chapman and Miles H. Smith.. ................ .. 153 On a certain Reaction of Quinine. By Professor G. G. Stokes F.R.S.. ,. . . . 174 On the Determination of the “Total Carbon” in Cast-Iron By Arthur H. Elliott.. .. . . .. .. .... ........... .............. . ........ ..... . 182 On some Decompositions of the Acids of the Acetic Series. By Ernest T. Chapman and Miles H. Smith.. ........ . . ... . ...... .. ......... 185 Note on Coumaric Acid. By W. H. Perkin F.R.S. .. .......,. . ,. . . .... 191 On the Propyl Compounds derived from the Propjlic Alcohol of Fermentation. By Ernest T. Chapman and Miles H. Smith .. ...........,... 193 Note on Bromide of Amyl. By Ernest T. Chapman and Miles H. Smith 198 On the Atomicity of Sodium. By J. A. Wanklyn . . . ... ... ,.......,... 199 The Chemistry of the Blast-furnace. By I. Lowthian Bell.. ......... . .. 203 On the Constitution of Hyposulphurous Acid. By C. Schorlemmer.. .... 254 Note on Sulphate of Alumina from Iquique Peru. By F. Field F.R.S.. .,. 259 On Regnault’s Chlorinated Chloride of Methyl. By W. H. Perkin F.R.S. 260 Proceedings at the Meetings of the Chemical Society. . .,.. . . . .... . ... . ... 263 Anniversary Meeting .. ... . ..,.. .. .. . ... .. ,...... . . .,. . . . . ...... . .. 1 Researches on the Constitution and Reactions of Tyrosine. By J. L. W. Thudichum M.D. and J. Alfred Wanklyn.. .. ... . . . ,.,.. . . .... 277 Note on Oxslate of Silver. By J. L. W. Thudichum and J. Alfred \,Wanklpn.. . . . .. . .. .... ,. ...... .. .. ... . . . . .. .... ....,...,.,. 292 CONTENTS. PAG3 Note on Dumas’ Method of determining Nitrogen. By J.L.W.Thudichum and J. Alfred Wanklyn ...... . ,...,......,.,................... 293 Further Experiments on the Atomic Weight of Cobalt and Nickel. By W. a. Rnasell Ph.D. , ,....... .. ,.............,...,............... 294 On Ethyl-hyposulphurous Acid. By R. H. Smith F.C.S...... . . . . . . . .... 302 On Chlorhydrated Sulphuric Acid. By the Reverend Stephen Williams Professor of Chemistry Stonyhurst College.. .......... . .... . .. . .... 304r Apparatus for deberniining the quantities of Gases existing in Solution in Natu- ralwaters. By Herbert McLeod.. . . ... . ..... . ...... . ....... . ... 30? On a New Form of Appa.ratus for Gas Analysis. By Eerbert McLeod.. . 313 Note on the Ab9orption Spectra yielded by certain Organic Substances. ByDr. T. L &cBy Prof. A. W. Williamson Pree.€%em. %c. .. . . . . .. . . . ..... .... . ,.. . ... . . ...,..,...,. . ,. . . ,,,.. By A. Kekul6 and T. E. Thorpe,. ..,,+. Phipson F.C.S............... ..,.....,.........,.,.... 324 On the Atomic Theory. F.R.S. 328 On Etbylbenzoic Acid. ..,....86% On Hydrduoric Acid. By G.Gore F.R.S. ....,........ . . .,. . ..,,.,,. 368 On the Pruducts of the Destructive Distillation of Animal Bubstancee. By Thomas Anderson M.D. Profesmr of Ciiemietry in the University of Glasgow. ...,... . . ..1 .,. . . .* ......L . . . . ,* .. . ......,. . . . . . . . . . 406 On the Products of the Action of Nitric Acid on the Resinous Extract of Indian Hemp. By Thomas Bolas F.C.S. and Erneste Francis Demmtrator in Chemistry Chring Cross Hospital ,. . . . . . ..... . 41’7 On the Relation of Hydrogen to Palladium. By the late Thornas Graham F.R.8............. ,. ,.,............................. .. .. ........ 419 Discussion on Dr. Williamson’s Lecture on The Atomic Theory Novem- ber&h,I869................................................,... 433 On the Formation of Carbonic Ether. By Wm. Dittrnar F.R.N.E. and Goo. Cranston Edinburgh.. . . .... . .......................... . .. 441 On the Dissociation of Liquid Sulphuric Acid. By Wm. Dittmar B.R.S.E. 4146 INDEX........,..........,....................................,... 491

ISSN:0368-1769    

DOI:10.1039/JS86922FP001

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

GLADSTONE ON SOYE COSEPOUNDS OF PHOSPHORITS ETC. 15 11.-On Some Compounds of Pliosplmrus containing Nitrogem By J. H. GLADSTONE, Ph.D. F.R.S. THREEseries of acid bodies all phosphoric amides have been described in previous papers. They are respectively The Pyrophosplioric Amides." Pyrophesphamic acid .................. P,(NH,)H3OGI Pyrophosphodiarnic acid ................ Y,(NH,),H,O,. Pyrophosph otriamic acid. ............... P,(NH,) ,H 0,. The T etraphosphoric Amides.? Tetraphospho-t etramic acid ........... P (NH,),H,O,. Terammoniated tetrap hosphodinmic acid. . P4(NH,) ,N,H,,O, Tetraphospho-pent'azotic acid .......... P,N,H,O,. The Thio-phosphoric Amides.$ Thio-phosphamic acid .................. P(NH,)H,SO,. Thio-phosphodiamic acid ..............P(NH,) ,HSO. During the investigation a number of other compounds have * Quart. Journ. Chem. Sac. February 1868 et. al. + Ibid. July 1868 et. al. $ Ihid. January 1865. GLADSTONE ON SOME COMPOUNDS been noticed and more or less fully examined,-and I now propose to group together these miscellaneous observations. Amidated Oxychlorides of Plzospl~o~~us. When oxychloride of phosphorus is exposed to a slow current of ammonia gas at a temperature of 0" centigrade it combines to form a solid white body and in so doing increases in weight about 22 per cent. This indicates the absorption of two mole- cules of ammonia; but on standing at the ordinary temperature the smell of the oxychloride always reappears and the con- tinuous passage of ammonia even at zero will cause a further increase of weight.At a higher temperature the combination proceeds much more rapidly and the increase through absorp- tion amounts to about 44 per cent. In either case the solid mass cakes together and it is necessary to break it up frequently in order to insure the saturation of the oxychloride. The most natural supposition is that the ammonia removes one or two equivalents of the chlorine their place being filled by amidogen thus PC1,O + 2NH = PCT,(NH,)O + NH,Cl. PC1,O + 4NH = PCl(NH,),O + ZNH,Cl. The increase in weight in the first case should be 22-15 per cent. in the second 44.3 per cent. That this is really the case is a matter of which there can be little doubt though all my efforts to separate either amidated compound from the chloride of ammonium have been fruitless.Water decomposes them at once giving rise to pyro-or tetra-phosphoric amides and absolute alcohol decomposes them in some other manner while no other solvent presented itself which was capable of dissolving the one and not the other sub- stance. Still zt mixture of alcohol and water warnsfound to effect a partial separation. Thus when a portion of PC1,O com-bined with 4NH was washed with small quantities of ordinary methylated spirit a great deal of chloride of ammonium was diesolved at once but for a long time the insoluble portion continued to yield some chloride of ammonium leading to the conviction that it was slowly formed; the long washed sub- stance was divided iiito two portions; one was heated per se and gave off ammonia and.cldoride of ammonium while the OF PHOSPHORUS CONTAINING NITROGEN. other was treated with water which decomposed it at once wit11 the evolution of heat and the production of the usual amidated acids together with chloride of ammonium. Some of the sub- stance resulting from the action of ammonia and oxychloride of phosphorus was washed with absolute alcohol ; a portion dis- solved with evolution of heat while there remained what proved to be almost pure chloride of ammonium. The alco- holic solution evaporated to dryness in vacuo and re-dissolved in water showed that some compound ether of an aromatic odour had been formed and it gave no inclications of either ortho-or pyrophosphoric acid or the amides of the latter but rather of nietaphosplioric acid ; chlorine mas also present.It has already been stated that when the -compound of oxychloride of phosphorus and four equivalents of ammonia is heated at or above 200' centigrade its constitution is so altered that it gives a different acid amide on the addition of water. Some of thin was washed with absolute aleohol till the chloride of ammonium was gradually but completely removed ;there remained a white powder which when treated with water gave the tetrsphospho- pentazotic acid while the solution gave some indication of pyro-diamic and hydrochloric acids. These three experiments all show a separation of the white powder into chloride oi ammonium and some other chlorinated body but in no case was the amide obtained in a state fit for analysis; in the last instance the small amount of chlorine (6.67 per cent.) showed that the transformation into an acid amide had been partially effected during the washing with alcohol.The transformations of these amidated oxycldorides under the influence of Tyater have been describccl iu previous papers. If the white powder produced by the treatment of osychlo- ride of phosphorus with more than two and less than four equivalents of ammonia be allowed to stand for some time the amell of the oxychloride develops itself and if it be heated the reproduction of this substance is still more evident. It would seem probable therefore that the lower compound is capable of transforming itself slowly into the higher compound and the original oxychloride 2(PC12NH,0) = PCl(NH,),O + PC1,O.The last atom of chlorine cannot be replaced by treating the VOL. XXII. c GLADSTONE ON SOME COMPOUNDS powder with gaReous ammonia at any temperature short of that at which the substance itself is decomposed,-above 300" centi-grade. Indeed I have never succeeded in preparing such a substance as Schiff 'B phospho-triamide. If the mixtiires of amidated oxychloride of phosphorus and chloride of ammonium above described be strongly heated they give up all their chloi-ine and hydrogen and part of their nitrogen leaving behind a white amorphous substance fusing at a bright red heat incapable of combining with either acids or bases and difficult of decomposition.This is the substance which has been described by various names and has the corn- position PNO. That it was really this substance has been proved both directly and indirectly. A portion of the mixture PC12(NH,)0 + NH,Cl when heated gave off chloride of ammonium and hydrochloric acid and lost 32-45 per cent.; the theoretical loss should have been 32.36 per cent. 0.289 gramme of the residue fused with nitre and carbonate of sodium gave 0.525 grm. of pyrophosphate of magnesium. This agrees with the calculated amount. Calculated. Found. Phosphorus . 5042 Nitrogen ...... 22.95 50.73 - Oxygen ...... 26-23 100*00 The decomposition will be as follows :- PC1,NH20 = 2HC1 + PNO. The same substance is produced when tfhe higher amide is decomposed by heat in which case the decomposition will be- PC1(NH2),0 = NH,Cl + PNO.As Gerhardt's original name bi-phosphamide will be gene- rally considered inapplicable to a substance of such a coni-position I suggegt the name phosphonitryle. PNO mrtp be OF PHOSPHORUS CONTATNT?;G ?;ITROQES. theoretically derived froni the ammonium salt of my variety of phosphoric acid by tJhe subtraction of all the hydrogen in the form of water P(NH,)H,O = PNO + 3H,O. P(NH,)O = PNO + 2H20. P,(NH,),H,O,= Z(PN0) + 5H,O. An attempt to prepare it by heating the pyrophosphate of ammonium gave a negative result. According to the notes of my assistant the late J. D. Holm es a series of bodies having the coinposition of pyrophosphonitry- lates may be prepared by heating pyro-triamates His aiialyses were very satisfactory but in repeating the experiments I have never succeeded in obtaining the same results ; at any rate the substances prepared by me have never been pure.The follow- ing account therefore must be understood as restiiig on the authority of his notes. ‘(PJ-rophosphotriamateof potassium when ignited evolves two equivalents of ammonia P,N,H6K0 = P,NKO + 2NH, leaving a residue which may be considered as the potassium salt of a new acid pyrophosphonitrylic (P,NHO,). This salt is a fused transparent glass quite insoluble in water; when ground to a very fine powder in an agate mortar and diffused through .cvat,er it is deconiposed by a solntion of AgNO beiiig deposited as a white heavy precipitate which becomes converted on standing into microscopic crystals.” In his experiment 0.684 grm.lost 0.073 that is 10.6 per ceut. In my experinient 0.892 grm. lost 0.097 that is 10.8 per cent. This is not in accordance with the formula given above which will require a loss of 15.9 per cent. Mr. Holnies gives the analysis of the silver salt and an nnalo gous copper salt. I. 0.4325 of the silver salt gave 0-2445 of chloride of silver and 0-4295of the ammoniochloride of platinum. 11. 0.4055 gave 0.2305 of chloride of silver. These results give numbera not very different from those of the formula P,NAgO,- c2 GLADSTONE ON SOXE COMPOUNDS Calculated. Found.-\ I. 11. -Phosphorus. . 25.00 -c Nitrogen. ... 5-65 6.22 Silver ...... 43-55 42.54 42-78 Oxygen .... 25-50 -100*00 0.345 grm. of the copper salt gave 09785.of oxide of copper and 0.4405 of aimnionioc'thride of platinum wliich agrees well with the formula P2NCu04-Calctdated. Found. Phosphorus. ... 36-13 -Nitrogen ...... 8.16 8900 Copper.. ..,. 18.41 18.15 Oxygen ...... 37-30 -7-100~00 If pyrophospho-triamic acid itself be heated at a low redness it gives off ammonia without any water. Mr. Holines found t,hat 0.6585 grm. lost 0.065 that is 9.87 per cent. In my experiment 1.555 grm. lost 0.145 that is 9-3 per cent. P,N,H,O -NH requires 9.71 per cent. loss. The residue was a semi-fused grey mass insoluble in water but gradually decomposed bv that substance even by the moisture of the air which resolves it into a mixture of acid amides and ammonium salts in which pyrophosphamic acid is most prominent but in which may also be detected the tetra- phosphoric compounds precipitsble by alcohol.Mr. H olm e s gives the following analysis of the residue I. 0.275 grm. gzve 0.7715 of mnmoniochloride of platinum. 11. 0.312 grm. gave 0.4375 of pyrophosphate of magnesium. Which agree with the formula P,N,H,O,. Calculated. Found. -I. II. Phosphorus. 39.24 39.15 I Nitrogen. ... 17-72 17-55 -Hydrogen .. 2.53 -c Oxygen , . . 40.51 -I 100-00 OF PHOSPHORUS CONTAINING NITROGEN. This may be considered as the pyrophospho-nitrplate of ammonium P,N(NH,jO, but I did not succeed in decomposing it by hydrochloric acid into NH,Cl and P2NH0 as I hoped.Ita resolution irito pyrophosphamic acid is what might be anticipated of a nitrylste P,N(NH,)O + 2H20 = P,NH,OG 3-NH,. If this semi-fluid acid be heated per se at 100' C. it gradnally gives off ammonia and something which has a smell resembling nicotine and beconies a white brittle solid dissolving in water from which alcohol throws down no precipitate. The result seems to be principtilly pyrophosphamate of ammonium. If it be heated at a higher temperature some yyrophosplio-trinmic acidis also produced. If however the experiment be con-ducted at a temperature of about 220' C. ammonia is given off as before and the resulting solid white mass is resolvable by cold water into two portions ; in the solution are found pyro- phospho-diamic and perhaps tetraphospho-tetramic acids ; undissolved is an amorphous solid which is very sparingly soluble in cold water but is instantly dissolved by warm water or by cold dilute solutions of mineral acids giving rise to pyro-phospho-diamic acid.0.252 grm. of the substance not diseolved by cold water gave 0.57 of ammoiiiochloride of platinum and 0.292 of pyrophos- phate of magnesium. This agrees best with the simple formula PNH,O Calculated. Found. Phosphorus.. .. 31.96 32-36 Nitrogen ...... 14.43 14-18 Hydrogen .... 4-12 -Oxygen ...... 49.49 I 100~00 but as this substance is most easily resolvable into P2N2H60 and H,O it seems necessary to double if not quadruple the above formula.If we allow ourselves to speculate we may imagine it P4N4Hl4Ol1, that is the semi-fluid acid P4N5Hl,OI1 from which NH has been driven by heat. CHURCH'S MINERALOGIOAL NOTICES. ~etrapliospho-tetrinzicAcid. It has been previously shown in describing the reactions of tetraphospho-pentazotic acid that under the influence of ni6rate of silver it is broken up with formation of tetrqhosphotetri-mate of silver. It has since occurred to me that this reaction might have a further bearing on the rational constitution of this body than was seen at first. If the silver salt merely trailsforins it from P,N,H,O to P,N,H,Ag,O by the eliniiiiation of NH as well as the bssic hydrogen the pale yellow salt should be to the original compound in the ratio of 315 to 512 or as 100 to 162.5.But if the tetrimic acid P,(NH),II,O pre-exists in the compound in combination with P,N6H120,,only about half that amount of silver salt will be produced and t'he solution mill contain the soluble products of decomposition of the hexamide. On performing the experiment the silver salt actually obtained showed an increase of 50.1 per cent. on the origiiial compound. This falls little short of the theoretical 62.5 and indicates that the reaction must Zmve been of the character described in the first instance. On removing the excess of silver from the solution it did give the usual reactions of tetraphospho-tetramic and pyrophospho-diamic acids as well as ammonia but these were probably secoiidary products of decomposition due to the slight excess of nitric acid.If the views already given of the tetraphosphoric amides be correct other bodies of a sirnilar character might doubtless be prepared ;indeed during the progress of the resesrcli indications of such have been met with but their reproduction and separation fkom one another are attended with extreme difficulty.

ISSN:0368-1769    

DOI:10.1039/JS8692200015

出版商:RSC    

年代:1869

数据来源: RSC

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CHURCH’S MINERALOGIOAL NOTICES. I11.-Mineralog icaI Notices. By A. H. CHURCH. 1. Analysis of a Meteorite from South Africa. THEmeteorite or rather aerosiderite which forms the subject of the present note is reported as having been seen to fall on CHURCH'S MINERALOQIOAL NOTICES. the 20th of March in the present year. The locality of the fall is gireii as about two days' journey N.N.E. of Griqua TOWI~, at a plact. lmowii as Daniel's Kid. The native a Griqua who saw it fall near his hut said it smelt strongly of sulphur and was warm when he picked it up. It was offered by this iiiaii to the Rev. James Good a missionary in Griqua Town and finally given to a Griqua chief-Captain Nicolas Wat erboer ; fibom Captain Wa t erboer Mr. J. R. Gregory obtained it.This meteorite was of small size weighing about 2 lbs. 5 oz. There is it crust upon it ha,ving it dark grey colour here and there speckled with reddish brown spots these spots resulting froni the partial oxidatmion of the ferruginous materials of the stone are more conspicuous a little way beneath the crust'. The ground-mass of this meteorite appears under the micro- scope to be greyish and yellowish white. Pretty uniformly dis- tributed tlzroughoiit its substance are numerous small particles grains and bunches of nickel-iron presenting its usual metallic appearance. Two other minerals may also be detected ill t'his meteorite namely t'he ferrous sulphide lmowii as troilite and tlie somewhat uiidetermined species called schreibersite.The density of this meteorite is rather low considering the large quantity of metallic iron which it contains. Two deter- minations of the specific gravity gave t,he following nuin-bers :-1. D = 3.657. 2. D = 3.678. I think it lil~elythat the pieces with wliich I experimented con- tained minute air-cavities; they were also not free from ferric oxide arising from partial alteration. In order to analyse the meteorite it wits finely powdered and digested in the cold with dilute hydrochloric acid; by this treatment the nickel-iron and troilite were dissolved ; tho quantity of the latter sulphide present was very evident the first portion of the hydrogen evolved by the acid being much mixed with sulphuretted hydrogen. It was found that acetic acid also was capable of decomposing the troilite.The iron and nickel present in the acid solution were separately deter- mined while tlie sulphur was estimated by a separate experi- ment the mineral being oxidized by nitric acid and potassium chlorate and then the snlphuric acid formed weighed as barium sulphate. CHURCH’S IIIKERALOGICAL KOTICES. Beveral att#emptswere made to deteiiiiiiie the schreibersite iii the meteorite. It was approximately estimated by calculating its amount as being ten times that of the unoxidized phos- phorus in the stone ; this method gave uniform results. The final results of .the analpip of several small fragments of the meteorite were as follows :- Nick el-iron .. .. .. .. .. 29-72 Troilite calculated as FeS... .. . . 6-02 Schreibersite ,. me .. .. .. 1.59 Silica and Silicates .. .a .. .. 61-53 Carbon Oxygen other constituents and loss.. 1.14 1oo*oo The nickel-iron alluded to above contained the following proportions of nickel and iron :-a. Iron .. .. .. 94.72 Nickel .. .. .. . 5-18 It appears from other analyses which I have made that the nickel-iron in this stone is not distributed with perfect uni- formity throughout its mass. One fragment gave me 2.03 per cent. of metallic nickel as existing in 100 parts of the meteorite; a proportion which would correspond to 37.17 per cent. of metallic iron or 39-20 of nickel-iron. The silicates of this meteorite are chiefly olivine and labrado- rite the former species constituting by far tlie larger proportion of the powder unaffected by dilute acida.la two portions of the same sample the silicates after deducting the schreibersite &c. amounted to 61.53 per cent. 61.10 ? In the analysis of another fragment the silicates were found not to exceed 48.99 per cent. 2. Action of Xcrlt on Chessylite. In 1864 I commenced a series of experiments on this mbject. I hoped to elucidate the foimation of atacamite when sea- PERKIN ON THE ACTION OF CHLORIDE ETC. water acts on copper ores. The only really successful experi- ment was one in which the following suhstmces had been placed together :-200 cub. cent. of a 10 per cent. soliit.ioii of pure salt gave 2 gins. of chessylite. The blue colour of the finely powdered chessylit,e slowly disappeared a pale green tilit taking its place while at the game time the saline solution became notably alkaline from the conversion of the sodium chloride into carbonate. In the followiiig table the composition of chessylite of its chlorinated product and of atacsmite are compared together :-2CuC03.C~H202 2C~C12,9C~H,02,3Aq.(?) Chessylite. Chlorinated product. Atacamite. CuO.. .. 69.2 59.55 53.6 CO .... 25% -0.. H,O . 5.2 18.14 16.2 cu .... -10-47 14.3 -11.70 16.0 .

ISSN:0368-1769    

DOI:10.1039/JS8692200022

出版商:RSC    

年代:1869

数据来源: RSC

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PERKIN ON THE ACTION OF CHLORIDE ETC. JV,-Nobe 011 the Action of Chloride of Lime on Aniline. By W. H. PERKIN, F.R.S. ABOUTtwelve years ago when studying the process of con-verting aniline into aniline purple by means of bichromate of potassium I very naturally made experiments also upon the oxidation of aniline by means of chloride of lime to see if the colour of the reaction pointed out by Runge was really due to aniline purple or not; but the result,s I obtained were of so decidedly negative a character t,hat I did not pursue t.he inquiry very far especially as my time was then much occupied. Two or three years after the aniline purple had been intro- duced commercially French manufacturers began to experiment upon this colouring matter and succeeded in preparing it by oxidizing aniline with chloride of lime.PERKIN ON THE ACTION OF This hct puzzled me very considerably but by following their process I found that they were correct and that aniline purple could be produced by iiieaiis of a salt of aniline and chloride of lime; but I was at that time uiialole to look more fully into the matter though I could not believe that my prc-vious conclusions were erroneous. Lat’elyI had the curiosity to repeat my original experiments and was pleased to find they gave confirmatory results. R uiig e it will be remembered designated aniline lqaiiol or blue oil on account of the blue reaction it gave wit’h chloride of lime. If this reaction be performed properly Run ge’s state- ment is found to be perfectly correct ; bnt if too much chloride of lime be employed brown products are likewise produced arid these when mixed with the blue give an impure purple colour.In makiiig thip experiment it is best to me a solution of hydrocli’lorate of aniline and a very dilute solution of chloride of lime adding the latter reagent in small quantities at a time ; by this mettiis a dark slightly opaque indigo coloured solution is obtained. The dull appearaiice of this solution is due to tlie presence of suspended colouring matter and if it be niixed with about its own bulk of alcohol it becomes perfectly clear and of a bright blue COIOU~’ like that of ammoniacnl sulpliate of copper but in no way similar to that of aniline purple. I have made a few experiments for the purpose of isolating this blue colouring matter and have succeeded tolerably well.If a large qiiantity of a cold dilute solution of liydroclilorate of aniline be treated with a very dilute solution of chloride of lime so as to produce as much of the blue product as possible and then saturated with chloride of sodium the colouring matter is precipitated and may be collected upon a filter. This product is of a black colour and very impure; when pressed it forms it soft pitchy mass. It may be purified however by treatment with cold ether or benzol which removes brown resinous bodies. The product thus obtained dissolves in alcohol producing a very fine blue solution. I therefore propose to call it Runge’s blue. Its solution when evaporated on a glass plate leaves the colouring matter with a coppery coloured surf‘we.Runge’s Flue is the salt of an organic base possessing properties quite different from thoae of mauveine The blue CHLORIDE OF LIME ON ANILINE. alcoholic solution when mixed with hydrate of potassium changes to a reddish brown colour but is reconverted into blue by the addition of an acid. An alcoholic solutioii of a salt of mauveine when treated with caustic alkali gives a violet reaction. The sulphate of this blue colouring matter appears to be difficultly soluble in water. The instability of this product has prevented me from getting it into a aufficiently pure state for analysis. Runge’s blue dyes silk of a blue or blue violet shade but does not possess such an affinity for this material as a salt of mauveine.It will be asked-if a solution of hpdrochlorate of aniline produce Ittunge’s blue with chloride of lime how is it that manufacturers produce aniline purple with the same reagent? The answer to this is that the manufacturer goes a step fur- ther and boils his product. I find that an alcoholic solution of Runge’s blue when heated rapidly decomposes with formation of aniline purple which may be obtained in crystals upon the addition of a little sulphuric acid. This change likewise takes place in the cold after the lapse of twenty-four hours. This decomposition can very well be shown by dyeing a piece of woven silk with Runge’s blue and then exposing it in parts to the action of steam when the parts so treated will change in colour from blue to that of aniline purple. Exposure to heat will also produce the same result. Therefore Rung e’s reaction does not produce aniline purple but a blue colouring matter which decomposes when heated yielding a salt of mauveine.

ISSN:0368-1769    

DOI:10.1039/JS8692200025

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

28 V.-Research on Acids of t7te Lactic Series.-No. 1. Synthesis of Acids of the Lactic Series By E. FRANKLAND, F.R.S. Professor of Chemistry in the Goveinment School of Mines; and B. F. DUPPA,Esq. F.R.S (Fromthe Philoaophical Tramactions for 1866,) WITHthe exception of the acetic series no family of organic acids has excited so much interest amongst chemists and been the subject of such numerous researches as that represented by lactic acid. Its character intermediate between the mono- basic and bibasic acids its close relations to the acetic and acrylic families and the numerous important transformations which it undergoes have all contributed to render this family an attractive subject for experimental inquiry and a fruitful source of theoretical speculation.These inquiries and hypo- theses have contributed greatly to the elucidation of thc habits of these acids and still more to the general progress of organic chemistry. Nevertheless there are two circumstances which have materially interfered with their complete success ; t.hese are the comparat,ively small number of the known members of this series and the absence of any synthetical proof of the nature of their constituent radicals. These obstacles to a more satisfactory conception of the internal architecture of the acids in question we have eddeavoured to remove by the production according to purely synthetical methods of a number of new members of this series a brief notice of which we have from time to time had the honour of submitting to the Royal Society,' and the more complete history of which we propose to de-velop in the following pages.Our general method for syn- thetically producing the acids of the lactic series depends upon the replacement of one of the atoms of dyad oxygen in oxalic acid or rather in the ethereal salts of oxalic acid,.by two semi- molecules of monad alcohol radicals. Such a replacement at once transforms bibasic oxalic acid into a monobasic acid of the lactic series. The nature of this transformjition as well as * Proceedings of the Rojal Society pol. xii p. 396; pol. xiii p. 140; vol. xiv pp. 17 79 83 191 197 and 198 FRhNRILhhD AND DUPPA'S RESEARCHES ETC. the relations of oxalic acid to the lactic family is clearly seen from t,he following comparison of the formule of oxalic acid and of its derivative diinethoxalic acid :-This snbstitution of :dcohol-radicals for one atom of oxygeii in oxalic acid can be readily effected by act,ing upoil the ethereal salts of oxalic a,cid by the zinc-compounds of the alcohol- radicals.In this reaction ethylic oxalatci was mixed with rather more than its own volume of pure zincethyl ; the temperature of the mixture gradually rose and large quantities of gas were evolred consisting of about equal volumes of ethylic hydiide and * In this paper 0 = 16 C = 12 H = 1 Zn = 65 Ba = 137 Cu = 635; Ho = (OH) the monad radical hjdroxyl or peroxide of hydrogen ; Eto = (OCpHj) ethoxyl or peroxide of ethyl &c. + As large quantities of ethylic oxalate were required for this and the following reactions it became a matter of imporlance to prepare this compound in the most economical manner.After trying the numerous met.hods which have been recom- mended we found the following process to give the laygat product :-1,500 grammes of oxalic acid thoroughly dried at 100" C. are placed together with 1,000 grammes of absolute methylated spirit in a capacious retort which is thcn very slowly heated by an oil-bath to 100"C.,at which temperatuie water begins to distil over; when the thermometer has risen to 105" a steady stream of absolute methylated spirit is couducted to the bottom of the retort at the rate of about 80 grammes per hour the temperature being allowed to rise very slowly to 125"-130" C. Care Being taken on the one hand tbat alcohol shall not distil over in which case the temperature should be raised and on the other that the heat be not 80 great a.9 to cause the generation of gas.At this rate it requires about twelve hours to make the addition of 1,000 grammes of alcohol; after which the retort must be gradually heated to the boiling-point of ethylic oxalate and the remainder of the distillate which is the pure oxalic ether collected apart. By fractional distillation the first portions afford a considerable additional quantity of the pure product besides ethylic formate. During the final operation in consequence of the presence of some uncon-verted oxalic acid B quantity of gas is always evolved ; nevertheless in frequently repeated operations we have obtained an ainount of pure ethylic oxalate equal in weight to the dried oxalic acid employed.FRANKLAND AND DUPPA'S RESEARCHES ethylene and resulting from the decomposition of ethyl ac-cording to the following equation :-Ethyl. Ethylic hpnride. Ethylene. For the attainment of the desired result of the reaction it is best to prevent thia secondary decomposition as much as possible. This we succeeded in doing by preventing the tem- perature from rising beyond 60" or 70" C. until the operatioil wa8 considerably advanced. Afterwards it wits necessary to heat to 100"C. to complete the reaction. The mixture generally continues fluid but asmmes a light straw-dour and a thick oily consistency. On heating it to 130"C. in a retort no distillate passes over.If after cooling its own volume of water be very gradually added torrents of ethylic hydride are evolved and on subsequent distillation in a water-bath weak alcohol containing an ethereal oil in solution passes over; a further quantity of the oil may be obtained by adding water to the residue in the retort and contiiming the distillation on a sand-bath. By repeated rectification the alcohol can be approximately separated from the .water and oil whilst the latter may then be removed by a separator. The oily product so obtained was submitted to rectification when its boiling point rapidly rose to 175" at which tempera- ture the whole of the remaining and very large proportion of the liquid distilled over. The analysis of this liquid yielded numbera agreeing with the formula- C,H,,O,* We shall prove below that this body is the ethylic ether of an acid possessing the same composition as the leucic acid obtained by Strecker* in acting on leucine with nitrous acid.The two acids are probably isomeric; and we therefore prefer to call the one prepared synthetically dietlioxalic acid and the ether above analysed etliylic diethoxalate. The formation of ethylic diethoxalate is explained in the following equatioiis :-Ethylic oxalate. Zincethyl. Ethylic zincmonethyl Eincetbylo-diethoxalde. ethylate. f Ann Ch. Pharm. lxviii 54. ON ACIDS OF THE LACTIC SERIES. (COEto + CEt,(OZn"Et) 2H20 = -{EEb,",o + Zn"Ho + EtH. Ethylic zincmonethyl Ethylic Zincic Ethylic die thoxalate.diethoxalate. hydrate. hydride. The first of these equations expresses the action of zincethyl upon ethylic oxalate by which ethylic zincmonethyl diethoxa- late is formed." The second shows the action of water upon this compound by which the zincmonethyl (ZnC,H5) becomes replaced by hydrogen.? Although we have not heen able to isolate the ethylic zincmoiiethyl diethoxalate from the other product of this decomposition yet we have proved its existence by forming it synthetically as described below. Ethylic diethoxalate is a colourless tra,nspareiit and some- what oily liquid possessing a peculiar and penetrating etherea,l odour and a sharp taste. It is insoluble in water but readily soluble in alcohol or ether. Its specific gravity is 09613 at 18'07 C.; it boils at 175" C. and distils unchanged. Two deter-minations of the specific gravity of its vapour gave the numbers 5.241 and 5-23. the number 5.528. We have remarked on this and other similar discrepancies below. When zincethyl is added to ethylic diethoxalate previously cooled in a freezing mixture each drop of the zinc compound as it comes into contact with the ether hisses like phosphoric anhydride when dropped into water. Torrents of ethylic hydride are evolved and the mixture finally solidifies to a white teiiacious mass which melts on the application of heat and does not distil below 100" C. at about which temperature a violent action sets in ; a great quantity of gas is evolved and * This interpretation of the reaction wa~ first proposed by But1 erow (Bull.SOC. Chimique 1864 p. 116); and we have since confirmed it by the synthetical produc- tion of ethylic zincmonethyl diethoxalate as described below. + The final result of tbis reaction is exactly homologous with the production of glycollic acid by the action of nascent hydrogen upon oxalic acid described by Schulze (Ann. Ch. Phys. Ixvii 366) { ggEz + H = { z:hT + H20. Oxalic acid Glycollic acid FRANKLAND AND DUPPA’S RESEARCHES the residue solidifies to a pitch-like mass which 011 treatment with water and subsequent distillation yields about one-fourth of the ethylic diethoxnlste employed. If the above-mentioued white mass instead of being heated be mixed with water it effervesces strongly zincic hydrate is foimed and pure ethylic diethoxalate separates in quantity nearly equal to that origin- ally employed.In a quantitative experiment 12.93 grms. of zincethyl were treated with ethylic diethoxalate excess being avoided ; 15.67 grms. of ethylic diethoxalate were required to saturate t’he above quantity of zincethyl and the weight of ethylic hydride evolved which was carefully determined amounted to 3-08 grms. These numbers agree closely with those deduced from the following equation :-Ethylic Ethylic zincmonethyl diethoxalate. die thoxalate. Et7tylic xincmoneth,yl dietlmsakrte is a colourless viscous solid aoluMe in ether but apparently incapable of crystallisation. It absorbs oxygen with avidity and in contact with water effervesces strongly reproducing ethylic diethoxalate according to the following equation :--rcoQo + 2H,O -CEt Ho + EtII + Zn”HoZ’ \ Ethylic zincmonethyl Ettiylic die thoxalate.diethoxalate. Ethylic zincrnonethyl diethoxalate combines energetically with iodine; an ethereal solution of the latter added to it is almost instantly decolorized and a large quantity of et.hylic iodide is produced. 14 2 { gyp’/E9 + = {:‘t’zn// + Zn”I + 2Et1 Ethylic zincmonethyl {:%it diethoxalate. Ethylic zincodiethoxarate. It was obviously impossible to collect in a state of purity the ethylic iodide thus set at liberty without considerable losls ; ON ACIDS OF THE LACTIC SERIES. but the quantity of the pure iodide actually obtained warS 12 grms.The above equation requires 14.6 ems. On the removal of ether and ethylic iodide the mixture of ethylic zhcodiethoxalate and zincic iodide forms a transparent gummy mass easily soluble in ether carbonic disulphide or caoutchoucin but totally incapable of crystallising from any of itps solutions. All our attempts to separate these bodies have hitherto proved abortive; and it is by no means improbable that they are chemically combined. The existence of monad orgauo-zinc radicals such as zinc-monethyl receives further support from the slow action of oxygen upon zincethyl which clearly shows that there are two distinct stages in the process of oxidation. These stages have indeed already been indicat,ed by one of us in describing the reactions of this body." When a current of dry oxygen is made to pass through an ethereal solution of zincethyl dense white fumes continue to fill the atmosphere of the vessel until about one-half of the total qimntity of oxygen necessary for the com- plete oxidation of the zincethyl has been taken up.Then the white fumes entirely cease showing the absence of free zinc- ethyl and at the same moment the liquid which up to that time had remained perfectly transparent begins to deposit a copious white precipitate and the latter continues to increase until the remaining half of the oxygenis absorbed. If the pro- cess of oxidation be arrested when the white fumes cease to be formed the product effervesces violently when mixed with water owing to the escape of ethylic hydride; but when the oxidation is completed the white solid masbr produced consists chiefly of zincethylate and does not in the slightest degree effervesce in contact with water.The two stages of this reaction depend essentially upon the mccessive linking of the zinc with the two atoms of ethyl by means of dyad oxygen. The first stage of oxidation is expressed by the following equation :-Zn"Et, + 0 = Zn"EtEto. Zincethyl. Zincethylo-ethylate. The zincethylo-ethylate thus formed is perfectly soluble in ether and is instanIly decomposed by water according to the following equation :-* PhiIoaophical Transactions 1856,p. 258. VOL. XXII. D FRANKLAND AND DUPPA’S RESEARCHES Zn’TtEto + 2H,O = Zn”Ho -/-FlO + El0 Zincethjlo-ethyhte.Zincic Alcohol. Ethilic hydrate. hydride. Treated with dry oxygen zincethylo-ethylate in ethereal solution absorbs a second atom of that element; and it iR this further a.bsorption that constitutes the second stage above referred to resulting in the production of ziiicic ethylate Zn”EtEto + 0 = Zn”Eto,. Wanlrlyn” was the first clearly to point out the probable existence of zincmonethyl or rather its homologue zincmono- methyl indicating at the same time its radical function when he ascribed to the crystalline compound obtained in the preparation of zincmethyl the formula Zn,IMe.j. In the same memoir he also represented this compound as the analogue of mercuric methiodide Bu tlerowz has also prominently drawn attention to this behaviour of organic zinc-compounds and has succeeded in obtaining zincmethylo-methylate Zn”MeMeo in a condition approaching to purity by passing a stream of dry air through a solution of zincmethyl in rnethylic iodide.Butlerow’s success in obtaining this body and his failure in converting it into zincmethylate are both probably due to the comparative insolubility of zincmethylo-methylate in methylic iodide owing to which the first product of oxidation was to a great extent protected from the further action of oxygen. When however ether is used as the solvent in the case of zinc- ethyl the oxidized product remains in solution t.ill the first fitage is passed after which zinc-ethylate is gra,dually pre-* Journ. Chem. SOC.1861 p.127. 1.Zn = 32.5 in this formula. 5 Bull. SOC.Chimique 1864 p. 116. ON ACIDS OF THX LACTIU SERIES. cipitated until the second stage is completed. Indeed as shown in the memoir above referred to (Philosophical Trans- actions 1855 p. Zt;S) the oxidation instead of stopping at the first stage proceeds even somewhat further than the second and the final product formed does not possess a composition in any degree approaching that which Butlerow asserts it to have. This is evident from the following numbers and from the circumstance that it does not effervesce in the slightest degree when mixed with water :-Percentage composition Percentage composition according to Butlerow’s according to mean of analyses.* c .......... 34-53 25.43 H ..........7-20 5-32 Zn.. ........ 46.76 42-04 0 .......... 11-51 27-21 100.00 100-00 When ethylic diethoxalate is treated with solution of baric hydrate it gradually dissolves even in the cold; on heating the solution in a water-bath a liquid having the properties of alcohol distils off; and on separating the excess of baryta by carbonic anhydride and filtration the salution yields on evaporationa crystallisable salt consisting of baric diethoxalate Baric diethoxalate is veiy soluble even in cold water ; when its boiling solution is precipitated with excess of dilute sulphuric acid and the baric sulphate removed by filtriztioii ether readily extracts diethoxalic acid from the cooled filtrate. On evapo-rating the ethereal solution the acid crystallises in splendid pris~ns,which after drying in vucuo gave results agreeing with the formula Je Philosophical Transactions 1855 p.268. FRANKLAND m DUPPA’S RE~OEES Die&oxalic acid is wry soluble in alcohol or ether and scgnewhat less BO in water. By the spontaneous evaporation of its aqueous solution it crystallises in minute prismatic needles ; but if a small quantity of dilute sulphuiic acid be added to the solntion the crystals are deposited in magnificent anorthic prisms which frequently attain a length of 1inch and a thick-ness of + inch. Diethoxalic add is greasy to the touch like stearic acid; it melts at 74”*5C. and slowly sublimes at the same temperature but is decomposed before reaching its boiling point.It has a Bour taste reddens litmus strongly aud expels carbonic acid from carbonates. It forms an extensive series of salts which are all soluble in water. In addition to the barium-salt described above we have examined the silver copper and zinc salts. Argentic diethoxnlate i8 readily prepared by boiling an aqueoua solution of the acid with excess of argentic carbonate. On filtration and evaporation in vacuo the salt crystallises in biilliant needles radiating from centres standing up freely from the capsule and containing half a molecule of water which is not expelled at 100” C Submitted to analysis this salt gave numbers indicating the forrnula Cup& diethoxnlate is obtained by mixing atomic proportions of bark diethoxalate with cupric sulphate filt.ering and evapo- ratiiig to dryness.The salt does not crystallise but dries down to a green gum-like mass which becomes nearly white on being reduced to powder. Submitted to analysis it yielded results agreeing with the formula &a& diethoaalate crystallises in nacreous scales which are sparingly soluble in water and in alcohol. Two determinations of the solubility of this salt in water at 16”C. gave the following results :-I. One part of the salt dissolved in 291 parts of water. ON ACIDS OF THE LkCTfU iSfiIlCS* 37 11. One part of the salt dissolved in 312 parts of wate Ite solubility in boiling water is not much greater. Although 80 difficultly soluble in pure water it dissolvea very readily in a solution of zincic iodide.The method of producing ethylic diethoxalate above dmcribed involves the previous preparation of considerable quantities of zincethyl but we have found that the process may be much simplified by generating the zincethyl during the reaction which is effected by gently heating a mixture of granulated zinc ethylic iodide and ethylic oxalate for several hours. After long experience in the production of this and other homo- logom compounds described below we have found the following process for the preparation of ethylic diethoxalate to give a maximum product. 600 grammes of a mixture consisting of one molecule of' ethylic oxalate and two of ethylic iodide were placed in a capacious flask with such a quantity of well-dried granulated zinc that the latter rose above the surface of the liquid.An inverted Liebig's condenser was attached to the flask. It ia preferable to use zinc which has been employed in a previous operation as it not only acts with greater rapidity but also at it much lower temperature. The flask was immersed in water maintained at a temperature of about 30" C. After a period of time which varies in each operation but is usually from twelve to twenty-four hours an energetic action sets in which must be checked by lowering the temperature of the water- bath. The reaction once commenced is usually completed in from twelve to eighteen hours the temperature of the water- bath being maintained at about 30" C. until it is nearly con- cluded when it may be raised to 100" C.The operation may be regarded as complete when the hot liquid assumes the con- sistency of honey and solidifies to a more or less crystalline mass on cooling although a considerable quantity of the mixed ethers is still unacted upon. Water being now gradually added until it equals three times the volume of the crystalline mass with which it must be well mixed by agitation a copious effervescence takes place ; zincic oxalate and oxide are formed in abundance whilst on the application of the heat of an oil- bath alcohol accompanied by ethylic diethoxalate distils over together with the ethylic iodide that has not been acted upon. This distillate is then treated in exactly the same manner aa 38 FR-D AM) DUF’PA’S RESEARCHES that already described for the separation and purification of sthyl-ic dietboxalate prepared by means of zincethyl.In the operation abow mentioned with 600 grammes of the mixed ethylic iodide and oxalate 86 grammes of pure ethylic dieth- oxalate were obtained the theoretical amount being 105 grammes. 11. Action of Zinc tpon a Mixture of Methylie Iodide and iMethylic Oxalute. Two molecules of methylic iodide were mixed with one mole- cule of niethglic oxalate and placed in contact with an excess of granulated zinc at 30”C. in a flask as above described. At the eoncluaion of the reaction the liquid solidified to a crystalline mass which on distillation with water yielded methylic alcoliol possessing an ethereal odour but from which no ether could be extracted.The residual magma in the flask consisting of aincic iodide zincic oxalate and the zinc salt of a new acid was separated from the metallic zinc by washing with water. It was then treated with an excesg of baric hydrate and boiled for R considerable time ; carbonic anhydride was afterwards passed through the liquid until on again boiling the excess of barytn was complctely removed. To the filtered solution recently precipitated argentic oxide was added until all iodine was removed. The solution separated from the argentic iodide was again submitted to a current of carbonic anhydride boiled and filtered. The resulting liquid on being evaporated on the water-bath yielded a salt crystallising in brilliant needles and possessing the peculiar odour of fresh butter.This salt is very soluble in water and in alcohol but nearly insoluble in ether and perfectly neutral to test-papers. On being submitted to analysis it gave numbers closely corresponding with the formula Dimethoxulic acid is obtained from its barium-salt by adcling dilute sulph-ruic acid to a concenti-ated eolutiorl of the latter and agitating with ether. 011 allowing the ether to evaporate ON ACIDS OF TRE LACTIC SERIES. spontaneously prismatic crystals of considerable size in ake their appearance. These yielded on combustion readts agreentg with the formula {Ee0 Piniethoxalic acid is a white solid readily crystallisiag in beautifid prisms resembling oxalic acid. It melts at 75O-7 C. volatilizes slowly even at common temperatures and readily sublimes at 50" C.being deposited on a cool surface in mag- nificent prisms. It boils at about 212"C. and distils unchanged. Dimetlioxalic acid reacts strongly acid and unites with bases forming a numerous class of salts several of which are crystal- line. In addition to the barium-salt above mentioned we have examined the silver-salt which is best formed by adding argeiitic oxide t'o the free acid heating to boiling and filtering when the salt is deposited in starlike masses of nacreous scales as the solution cools. On analysis this salt gave numbers closely corresponding with those calculated from the formula Attempts to prDduce ethylic dimethoxalate by digesting t-he free acid with absolute alcohol at a temperature of IGO" C.proved abortive traces only of the ether being apparently formed. Judging however from our subsequciit success in obtaining ethylic dimethoxalate as described below we believe that the methylic ether would probably be obtained by re-peatedly agitating with ether the aqueous &stillate obtained from the crude product of the original operation methplic di- niethoxztlate being evidently like ethylic dimethoxalate miscible with water in all proportions. Assuming the formation .of this ether its production fi-on1 the miztual action of zinc methylic oxalate arid metliylic iodide followed by that of water would be expressed in the following equations :-~~~~~ { + Zn'b + 4MeT = { CAfe'"Zn''Me) + Zn'/MeMeo + 2 Zn''i2 : CUMeo Methylic Methyli.zincmono- Zincmethylo-oxalate. methgl dimethouslate. methglate. Methylic zincmonome thy1 Metbylic Zincic hjdraie. dimetlioxalate. dimethoxalate. FRANgLBND AND DUPPA'S RESEAR4XiES Dimethoxalic acid exhibits the aame composition as Staedeler's acetonic acid Wurtz's butylactic acid and the oxybutyric acid obtained by Friedel and Machuca. The relations of these acids to each other will be discussed at the conclulsion of this paper. 111. Action of Zinc upon a Mixture of Ethylic Iodide and Methylic Oxalate. This reaction was performed in exactly the same manner as the last. On addition of water the product yielded on subsequent dbtillaiim a considerable quantity of an ethereal body which distilled over together with Che ethylic iodide that had not been acted upon.The additio-rl of water to the dis-tillate effected an approximate separation of the ethereal from the alcoholic portion; the former was then decanted and dis-tilled for the purpose of separating alcohol and ethylic iodide. When the temperature of ebullition rase to 100" C. the liquid left in the retort was placed OVZP calcic chloiide for twelve hours after which it was again sabmitted to distillation when its boiling point almost immediately rose to 165" C. (barom. 758.2 millims.) at which temperature the whole of the remain- ing liquid passed over. S~bmittedto analysis this liquid yielded resulk closely corresponding to the formula The decomposition of this e&er by baryta described below proves it to be the methylic ether of an acid of the same corn- position as dieihoxalic acid with which it also agrees in its fusing point.The composition of this ether may therefore be thus expressed (::has Methylic Diethoxalate is a colourless transparent and tolerably mobile liquid possessing a peculiar ethereal odour only re- motely resemblinz that of ethylic diethoxalate. It is very sparhgly soluble in water but readily soluble in alcohol or ether. Its specific gravity is -9896 at 16"-5C. It boils at 165' C. and distils unchanged Its vapour-density was found by experiment to be 4.84. The above formula corresponding to two volumes of vapour requires the number 5.03. ON ACIDS OF THE LACTIC SERIES. Trea,ted with caustic alkaline bases this ether is readily decomposed even in the cold yielding methglic alcohol and a diethoxalate of the base.A quantity of it was thus decom- posed with solution of baryta the excess of base being after- wards removed. It yielded on evaporation a crystalline mass very soluble in water alcohol or ether aid which on analysis gave results corresponding with those calculated from the formula of baric diethoxakute CEt,Ho Loo coO*a"* ICEt,Ho When this barium-salt in aqueous solntion is decomposed with the exact amount of sulphuric acid necessary the liquid filtered off fiom the baric sulphate and evaporated in vacuo the acid crystallises magnificently. Professor W. Hall ow s Miller of Cambridge has kindly examined and measured these crystals for us with the following results :-Anorthic :-100 110 = 66" 2'; 110 010 = 34" 15'; 100,001 = 76' 40'; 001 ioi = 29" 4'; 010,ooi = 75O 13'.Observed forms :-100 010 001 110,iio ioi Foi. Angles. 010,001 001 oio 75 13 104 47 100 001- 76 40 100 001 100 ioi Too ioi 103 20 105 44 74 16 100,201 loo 301 128 41 51 19 001,To1- 29 4 101,201 22 56 100 010 ioo 010 100 17 79 43 VOL. XXII. E FRANRLAND AND DUPPA'S RESEARCHES Angles. 100,110 66 2 010 110 34 15 010 iio 28 36 100,110 51 7 010 ioi 70 0 010) 201 69 31 110,001 68 19 -110 $01 91 52 110,001 84 50 iio ioi 66 16 iio 201 54 30 Combinations :-100,010,001,110 100 010 061 ioi loo 010 001,110,ioi 100 010 001 no Ti0 100 010 001 110,ioi $01 100 010 001,110,ioi iio 100 010 001 110,31,iio 201.Cleavage :-100 010 very perfect and easiIy obtained. The optic axes seen in air through the faces of the form 010 appear to mttke with one another an angle of about 71". De-noting by a b the extremities of radii of the sphere of pro-jection drawn parallel to the directions of the optic axes seen in air through the faces of the form 010 the arcs joining u,,tl and the nearest polea of faces are approximately as follows :- ON ACIDS OF THE LACTIC SERIES. This acid is readily soluble in ether alcohol and water ; it is greasy to the touch and nearly inodorous. It sublimes readily at 50' C. and slowly even at common temperatures a small quantity of the acid left on a watch-glass gradually disappear- ing though in other respects it is permanent when exposed to the air.It hses at 74'05 C. Submitted to analysis it gave numbers agreeing with the formula Argeiitic diethoxalate was made by adding argentic oxide to a hot solution of the acid. After filtration and evaporation in vacuo it crystallises in brilliant silky fibres adhering closely to the capsule. These are anhydrous and are scarcely discoloured by prolonged exposure to -a temperature of l00OC. They yielded on analysis numbers closely corresponding with those calculated from the formula CsH 1AgO3 Although the diethoxalic acid obtained by the action of zincethyl upon -methylic oxalate possesseR the same molecular weight and fusing-point as that prepared by the action of zincethpl upon ethylic oxalate yet the two acids do not appear to be identical.The silver-salt of the latter crystallises as above described (page 36) in brilliant needles radiating from centres standing. freely up from the capsule and containing half a molecule of wa.ter which is not expelled at 100" C. This salt also further differs from that just described by being rapidly discoloured when exposed to the heat of a steam-bath. In a future communication we hope to be able to throw additional light upon this apparent isomerism. IV. Action of Zinc upon a Mixture of EthyEic Iodide Methylie Iodide and Ethylic Oxalate. Having proved in the foregoing reactions the possibility of replacing one atom of oxygen in ethylic oxalate by two semi- molecules of either methyl or ethyl we thought it desirable to ascertain whether the same replacement could be effected by a L2 FRANKLAND AND DUPPA’S RESEARCHES semi-molecule of each of two different monad alcohol-radicals.We endeavoured to accomplish this by acting with zinc upon a mixture consisting of one molecule of ethylic oxalate and one niolecule each of the methylic and ethylic iodides by which we hoped to obtain an acid of‘ the following composition :-Experiment completely proved the practicability of this reac-tion; and its result even exceeded our expectations since not only was the ether corresponding to the above acid formed with the greatest facility but it was produced almost to the complete exclusion of the ethers of diethoxalic and diemeth- oxalic acids.200 grammes of ethylic oxalate were mixed with the proper atomic proportions of methylic iodide and ethylic iodide and were digested with granulated zinc for several days at a tem- perature of from 35O to 40’ C. until the supernatant liquid became oily and solidified to a crystalline mass on cooling. Water being now added till effervescence ceased the whole was submitted to distillation in an oil-bath. With the exception of a small quantity of the mixed ethylic and methylic iodides that had escaped decomposition the distillate consisted of a homo- genous liquid composed of water ethylic and methylic alcohols and an ethereal body which last was separated by repeated agitation with large volumes of ether and subsequent rectifica- tion.In this manner there was obtained a large quantity of a liquid which boiled constantly at 165O.5 C and yielded on analysis numbers very closely corresponding with the formula The production of this ether is explained in the following equations :-{ gEEi + 4Zn + SEtI + 2MeI = { ~~~~(oZn”Me) + Zn’EtEto + 2Zn”12; Ethylic EthyIic zincmonomethyl oxatlate. e thomethoxalate.. {CEtMe(OZn”Me) + 20-4 = (COEto CEtMeHo + MeH + Zn”Ho,. LCQEto Ethylic zincmonome thy1 Eihylic ethometh-Zincic ethomethoxalate. oxalate. hydrate. ON ACIDS OF THE LACTIC SERIES. A not inconsiderable amount of the ether thus formed in this and in the analogous reactions described above appears tlo be decomposed by the zincic hydrate; at all events an appre- ciable quantity of the zinc-salt of the derived acid is always obtained from the residue left after distillation of the ethereal product.Etliylic ethomethoxalate as we propose to name the new ether is a colourless transparent and mobile liquid possessing a penetrating ethereal odour much resembling t,hat of ethylic diethoxalate. It is very soluble in water alcohol and ether and has a specific gravity of -9768 at 13" C. It boils at 165O.5 C. ; and its vapour-deiisity determined by experiment is 4.98 the theoretical number for a two-volume vapour of the above formula being 5-04. Ethylic ethomethoxalate is readily decomposed even by aqueous solutions of the alkalies and of baryta yielding alcohol and a salt of the base By this means baiic ethomethoxalate was prepared.This salt crystallises from an aqueous solution as a beautiful radiated mass of silky lustre very easily soluble in water. Submitted to analygis it gave results agreeing with the formula By exactly decomposing this salt with dilute sulphuric acid and evaporating the filtrate first in a retort and afterwards in a vacuum ethornethoxalic acid was obtained as a splendid white crystalline mass fusing at 63" C. subliming readily at 100"C. and condensing in magnificent star-like groups upon a cold surface. It boils wit,h decomposition at 190" C. Ethometh-oxalic acid is very readily soluble in ether alcohol or water; small fi-agments of it thrown upon water rotate like camphor whilst dissolving.These solutions react powerfully acid and readily decompose carbonates. The analysis of this acid gave results corresponding with the formula FRANKLAND AND DUPPA'S RESEARCHES Argentic ethomethoxalate was prepared by treating the free acid dissolved in water with argentic carbonate. The salt crystallises in splendid mammillated masses half an inch in diameter which are tolerably soluble in water. It gave on analysis numbers agreeing with the formula V. Action of Zinc upon a Mixture of Am3lic Iodide and EtJbylic Oxalate. When a mixture of equivalent proportions of ethylic oxa-late and amylic iodide is digested with granulated zinc at 70' C. the zinc ia gradually dissolved while much amylic hydride and amylene are given off.The mixture finally assumes a viscous or semisolid condition and when treated with water produces a further quantity of amylic hydride which distils off at a gentle heat. On the subsequent applica- tion of a higher temperature water accompanied by amylic alcohol amylic iodide and an etrhe?l liquid distil over the three latter forming a mixture the s4rtration of which into its component parts presents rather formidable difficulties. After drying with calcic chloride the oily mixture begins to boil at about 132' C.; the product first passing over consists prin-cipally of amylic alcoliol mixed with amylic iodide. Afterwards the thermometer rapidly rises to 200' C. between which tem- perature and 203' C. a considerable section of the remaining liquid which we will call A passes over.There then occurs a further rapid rise of temperature until the thermometer remains stationary between 222' and 226' C. The section collected between these points we will call B. Finally the temperature rises to 260' to 2644 between which points the remaining liquid (C) pJsses over. By repeated hctional dist.illation the larger portion of the section A was obtained at the nearly fixed boiling point of 203' C. This liquid was submitted to analysis and yielded numbers coinciding nearly with the formula C9H1803 which interpreted by further results detailed below resolves itself into ON ACIDS OF THE LACTIC SERIES. The ethereal body with the lowest boiling point produced in this reaction is therefore ethylic am,ylhydrosalate or ethylic oxalate in which one atom of oxygen is replaced by one semi- molecule of amyl and one of hydrogen.This body also stands in very close relation to ethylic lactate ; for if the semi-molecule of methyl in ethylic lactate were replaced by amyl ethylic amylhydroxalate would be produced 6hylic lactate. Ethyl& amylhydroxalate. The two stages in the production of ethylic amylhydroxa- late are explained in the following equations :-Ethylic oxalate. Zincic amylo- ethylate. ~ Ctlg(zn"A~)(OZn"Ay)+ 40 = {~ g$iEHo+ 2Zn"Hoa + 2AyH. Ethylic amylhy- Zincic Amylic droxalate. hydrate. hydride. We have not attempted to give a name to the body fiom which ethylic amylhydrosalate is directly produced by the action of water as shown in the last of the foregoing equations The resources of chemical nomenclature already too severely taxed would ecarcely be able to elaborate a constitutional name for this body which consists of ethylic oxalate wherein au atom of oxygen is replaced half by amyl and half by zinc-monamyl whilst a second semi-molecule of zincmonamyl is mbstituted for a semi-molecule of ethyl.Ethylic amylhydroxalate is a somewhat oily transparent and slightly straw-coloured liquid of specific gravity -9449at 13' C. possessing a pleasant aromatic odoiir and burning taste. It boils at 203' C,; and its vapour-density determined by experi-ment is 5.47 the above formula requiring 6.0. To this dis-crepancy me shall refer again presently. Section B of the oily liquid after careful rectification gave a product boiling at 224-225' which yielded on analysis results agreeing with the formula FRANKLAND AND DUPPA’S RESEARCHES The above formula might be interpreted as that of etlb$ic nmylethoxalate the constitutional formula of which would be {%2Ho We were at first inclined to regard this as the actual constitu- tion of the new ether believing it to be possible that ethylic oxalate and am ylic iodide mutually decomposed each other pro-ducing a mixture of amylic and ethylic oxalates with the amylic and ethylic iodides ; an analogous decomposition of mixed ethereal salts of oxygen acids ha@ been recently noticed; but the test of experiment obliged us to abandon this view of the reaction.We found it is true a remarkable depression of temperature amounting to 9’03 C.on mixing one molecule of ethylic oxalate with one of amylic iodide; but on submitting the mixture to distillation the thermometer rose to the boiling point of arnylic iodide (147”)before ebullition commenced thus showing that none of the much more volatile ethylic iodide had been formed. No transfer of radicals therefore takes place when ethylic oxalate is heated with amylic iodide; and conse- quently no zincethyl can be formed when this mixture is acted on by zinc. We therefore prefer to view the ether now under consideration as ethylic ethyl-amylhydroxalate analogous in constitution to W ur t z’s ethylic ethyl-lactate.* (ggyo. {g&;fto. Ethylic ethyl-lactate. Ethylic ethyl-amylhydroxalate.On this view the following equations represent the formation of the ether :-{~~~~~ 1 Znt’J + 4AyI = CA$zn”Y)Eto + Zn’AyAyo + CLZn“1,: COhto Ethylic Amylic Zincic amylo- oxdate. iodide. amylate. CAy(Zn”Ay)Eto + 20H = + Zn”Ho,. {COEto Ethylic ethyl- Amylic Zincic amylhydroxalate. hydride. hydrate. * It deserves to be mentioned that the identity of boiling point between this ether and its isomer amylic diethoxalate described below does not favour this view since 8 eomparison of the boiling points of ethylic ethyllactate with that of ethylic etho- methoxalate and methJlic diethoxalate its isomers shows that the substitution of ethyl for the hydrogen of hydrosyl is attended with a depression of the boiling point equal to 8O.5 C.,the percentage composition of the compound remaining constant.ON ACIDS OF THE LACTIC SERIES. Ethylic ethyl-amylhydroxalate is a straw-coloured oily liquid possessing an aromatic but somewhat amylic odour and a burning taste. Its specific gravity was found to be 09399 at 13"C. It boils between 224' and 225O C A determination of the specific gravity of its vapour by G a y-L u ssa c's method gave the number 6-29 whilst the above formula requires 6.92. Section C of the oily product boiling about 262' C. was next submitted to investigation. It gave on analysis results agreeing approximately with the formula The body is therefore ethylic diamyZoxaZate the normal homo-lope of ethylic diethoxalate as is seen from the following com- parison :-Ethylic diethoxalate.Ethylic diamyloxalate. The production of ethylic diamyloxalate is explained by the following equations :-Ethylic oxalate. Ethylic ziincmonamyl-diamyloxalate. Zincic omylo-ethylate. + 20H2= {COEtoCAY'2Ho+ AyH + Zn"Ho2. diamyhxalate.Ethylic zincmonamgl- diamyloxalate.Ethylic hydride.Amylic hydrate. Zincic Ethylic diarnyloxalate closely resembles the two foregoing ethers in its appearance and properties. It is however a thicker oil and flows less readily and has the lowest specific gravity of any ether belonging to this series ita density at 13" C. being only -9137. The following compaiison of the specific gravities of all the ethers of this series shows that they generally increase inversely as their atomic weights :-Formula.Sp. gr. Temp. 0bserver. Ethylic lactate. . C H,,O 1.042 i3 Wurtz & Friedel. Ethylic dimeth-}C6 H1203 09931 13 F. & D. oxalate . . FRANKLAND AND DUPPA'S RESEARCHES Ethyliclactate ethyl-. . } Formula. 7 143 SP. gr. 0.9203 Temp.0 0 Obeerver. Wurtz. Ethylic etho-methoxalate I)'7 Methylic dieth-oxalate . . H14°3 0.9768 0.9896 13 16.5 F. & D. 97 Ethylic diethox- alate .. 0.9613 18.7 99 Ethylic amylhy- droxalate .. 0.9449 13 ?9 Amylicdiethox-alate .. 11 22 3 0.9322 13 99 0.9399 13 7) alate .. Ethylic diamyl- 0.9137 13 14 98 3 9, oxalate .. Ethylic diamyloxalate boils at about 262O and distils with little or no change. A determination of the specifk gravity of its +apour gave the following numbers :-Weight of ethylic diamyloxalate ..02048p. Observed volume of vapour .. .. 56.78 cub. centh. Temperature of bath .. .. .. 273OC. me Height of barometer . . .. 769millims. Difference of heights of mercury inside and outside tube .. .. .. 70millima. Height of spermaceti column reduced 0. to millims. of mercury. . .. 14millims. From these data the specific gravity 5-9 was deduced whilet the above formula requires 8.4. The investigation of these ethers has revealed a tendency to dissociation increasing with the weight of the semi-molecules replacing the atom of oxygen in ethylic oxalate. Thus beginning with ethylic lactate which has the normal vapour-density we find a gradual divergence culminating in ethylic diamyloxalate as seen in the following series of numbers :- ON ACIDS OF THE LACTIC SERIES.Vapour-densities. Name. Fo~ula.y-/ -\ Observer. Calculated. Found. Ethylic lactate.. C H,,O 4-07 4-14 Wurte & Friedel. F. & D. F.& D. Ethylic ethyl-C,,H,,O 6.92 6-29 99 alate .. methox-} C,,H,,O 6.92 6.74 97 alate .. Ethylic diamyl-5.9 oxalate . . We have likewise prepared the acids corresponding to the three ethers above mentioned. The fist is obtained by decom- posing ethylic amylhydroxalate with baryta treating the solu- tion of the barium-salt thus obtained with excess of sulphuric acid and then dissolving out the organic acid with ether. On evaporating the ethereal solution the acid remains as a thick oil which does not crystallise after several days’ exposure over sulphuric acid in vacuo.The calcium-salt forms a white crys- talline mass soluble in water. Submitted !o analysis *2102ern. gave 00877 grm. calcic sulphate corresponding to 12.27 per cent. of calcium the formula r CAyHHo C14H26Clt”06,or requiring 12.12 per cent. The barium-salt closely resembles that of calcium. -2476grm. gave on analysis 01334 grm. baric sulphate car-responding to 31.68 per cent. of barium. The formula FRANKLAND AND DUPPA’S RESEARCHES CAyHHo CI4H2,Ba“O6,or coo Ba” too CAyHHo requires 32.08 per cent. of barium. We have also obtaiiied a beautifully crystalline acid of the same composition as the above from its zinc-salt contained in the residue remaining after the distillation of the three ethers above described.AmyZl~ydroxa?icacid prepared from this zinc- salt is but sparingly soluble in water fi-om which however it crystallises in magnificent nacreous scales which fuse at 60O.5 C. but afterwards remain liquid for some time even at ordinary temperatures ; they are very unctuous to the touch and readily soluble in alcohol aiid ether. On analysis this acid gave results agreeing well with those calculated from the formula Thebarium-salt of this acid crystallises in large and beautiful nacreous scales like paraffin tolerably soluble in water ; -3765 grm. gave on analysis 02027 grm. baric sulphate corresponding to 31-66 per cent of barium. The formula C,,H,BBa”O, or requires 32.08 per cent. of barium.A copper-salt was also prepared. It is deposited from its aqueous solution in minute light-blue scales very sparingly soluble in water. Submitt,ed to analysis *2341grm. of it gave numbers agreeing closely with the formula fCAvHHo The acid of the second ether ethyLamyl7~ydroxalicacid is pre-pared by the decomposition of ethylic ethyl-amylhydroxalate with alcoholic potash. The acid is afterwards liberated by the ON ACIDS OF THE LACTIC SERIFS. addition of sulphuric acid in excess and may then be dissolved out of the mixture by ether. On the evaporation of the latter the acid remains as a thick oil gradually solidifying to a crys- talline mass which however did not appear to be in a fit state for the determination of its fusing point.The barium- and silver-salts of this acid were prepared. They are both soluble in water ; ,1331 grm. of baric ethyl-amylhydroxalate gave on decomposition with sulphuric acid 00660 grm. baiic sulphate corresponding to 29-15 per cent. of barium the formula ICAyHEto requiring 28.41 per cent. of barium. -1891grm. of argentic ethyl-amylhydroxalate gave on ignition -0722 grm. metallic silver representing 38.18 per cent. The formula requires 38.43 per cent. of silver. The acid of the thirdether (diamyloxalic acid) is best prepared by decomposing the ether with boiling baryta-water. After removing the excess of baryta in the usual manner baric diamyloxalate crystallises on evaporation in minute elastic needles which when dry have the appearance of wool.It is moderately soluble in hot water but sparingly so in cold. Two determinations of barium in this salt gave results agreeing with the formula C24H46Ba’’06, or If baric diamyloxalate be dissolved in hot dilute alcohol and excess of sulphuric acid be added the liquid after filtration contains diamyloxalic acid in solution. On heating upon a water-bath the alcohol gradually evaporates and diamyloxalic acid crystallises in the hot Bolution as a beautiful network of brilliant silky fibres which after being well waahed in cold FRANKLAND AND DUPPA’S RESEARCHES water and dried at loOo,yielded on analysis numbers agreeing well with the formula Diamyloxalic acid presents the appearance of coloiirless satiny fibres which are insoluble in water but soluble in alcohol or ether This acid is remarkable for its high melting point 122O C.in which respect it surpasses any of the acids of this series. Its melting point is very sharply defined and it solidifies immediately on a very slight reduction of temperature. Heated more strongly it sublimes and condenses on a cold sur- face in white crystalline flakes like snow. VI. Action of Zinc upon a Mixture of Ethylic Iodide and Anaylic Oxalate. Equivalent proportions of amylic oxalate and ethylic iodide were digested at 50’ to 60’ with excess of granulated zinc for several days. The reaction proceeded with extreme sluggish- ness and was not completed before the expiration of a week. The mass being then mixed with water and submitted to distil-lation an oily liquid passed over which on rectification was ultimately resolved into amylic alcohol and an ethereal liquid.Submitted to analysis the latter yielded numbers agreeing closely with those calculated from the formula of amylic dieth-oxalate CEt,Ho ‘11’22’39 Or { COAyo The two conswiltjive reactions by which amyIic diethoxalate is produced are expressed in the following equations :-coAYO + Znffq+ 4Etk { gEk$znf’Et) + 2n”EtAyo + SZnI ; (COAyo Amylic Amylic zincmonethyl- Zincethylo-oxalate. diethoxalate. amylate. + 2 OH = + EtH + Znf’Ho2. { g%; Amylic zincmonethy& Amylic dieth-Zincic diethodate. oxalate. hydrate. ON ACIDS OF THE LACTIC SERIES. Amylic diethoxalate is a colourless transparent and slightly oily liquid possessing a fragrant odour of a somewhat amylic character.It is insoluble in water but miscible in all propor- tions with alcohol and ether. Its specific gravity is -93227at 13' C. It boils constantly at 225" C. Its observed vapour-density is 6.74 the above formula requiring 6.97. Amylic diethoxalate is isomeric with ethylic ethyl-amylhy- droxalate described above. The nature of this isomerism is seen at a glance from the following constitutional formulae of the two bodies :-Ethylic ethyl-arnylhydroxalate { CAyHEto COEto Amylic diethoxalate . . The specific gravities in the liquid form and the boiIing points of arnylic diethoxalate and its isomer ethylic ethyl- amylhydroxalate are almost absdutely identical viz.Boiling point. Specific gravity. EthyliclethyI-amylhydroxalate 224'-225" C. 09399at 13' C. Amylic diethoxalnte . .. 225'C. *9323at 13' C. They are however at once distinguished by the products of their decomposition with alkalies ethylic ethyl-amylhydroxa- late giving ethylic alcohol and a salt of ethyl-amylhydroxalic acid whilst amylic diethoxalate yields amylic alcohol and a salt of diethoxalic acid. VIL Action of Zinc upon a Xwture of Arnylic Iodide and Amylic Oxalate When equivalent proportions of amylic iodide and amylic oxalate are gently heated in contact with zinc a brisk reac-tion soon sets in. After evolving much amylic hydride and amylene the whole solidifies to a gum-like mass which on distillation with water yields an oily liquid resembling that obtained when ethylic oxalate is employed.We have every reason to believe that the same series of ethers as those de-scribed under No. V. are here produced with the difference that they are amylic instead of ethylic ethers. This difference FRANKLAND AND DUPPA'S RESEARCHES of base however renders the separation of these ethers from each other a very difficult operation and we have therefore left this reaction comparatively unexplored. Two of these ethers were however collected ; the one boiling at about 280'-290' C. exhibited a composition approaching that of amy Zic diarnyloxalate CAy,Ho C17H3403' Or (COAyo . Amylic diamyloxalate is doubtless produced by the following consecutive reactions :-AmyG Amylic zincmonamyl- Zincic amylo- oxalate.diamyloxalate. amylate. + 20H2 = {giFF+ AyH + Zn"Ho2. Amylic zincmonamyl- Amylic di- Amylic diamyloxalate. amyloxalate. hydride. The second ether mentioned above boiled between 215' and 220' C. ; it was decomposed by alcoholic potash ; the potash- salt so obtained heated with dilute sulphuric acid yielded to ether an oily acid possessing the characteristic odour of caproic acid. This acid boiled with argentic carbonate suspended in water gave on filtration magnificent nacreous plates of a silver- salt which were very sparingly soluble in water only slightly acted upon by light in fact possessing all the properties of normal silver caproate and differing markedly from the isomeric silver diethacetate recently described by us.* Submitted to analysis this salt yielded results agreeing closely with thoae calculated from the formula of ailver caproate :-Unfortunately we did not submit to analysis the ether from which this caproic acid was obtained; but there can scarcely be a doubt that it was amylic caproate.We have stated that it boiled between 215" and 220O. The boiling point of amylic * PhilosophicalTransactions,vol. chi p. 37 and Jour. Chem. SOC. vol. iv (Ser. 2) p. 410. ON ACIDS OF THE LACTIC SERIES. caproate is not known; but ethylic caproate boils according to Fehling at 162’ C.; consequently the boiling-point of amylic caproate ought to be according t,o Kopp’s law 216*C. it number which lies between the points observed in the ether under consideration.It ib t>hus evident that the three variations in the action of’ zincamyljde upon an oxalic ether demibed above as giving rise to amylhydroxalic acid ethyl-amylhydroxalic acid and diamyloxalic acid do not exhaust the fertility of this reaction; and the production of caproic acid as above described shows that the action of these substances upon each other is sus-ceptible of yet a fourth modification in which the molecule of amylic oxalate appears to divide into its two constituent semi- molecules of amyloxatyl (COAyo) wliich then unite with amyl to form amylic caproate. {E:gz + Ay = 2CAyOAyo or 2 {gk%. Amylic oxalate. Amyl. Amylic caproate. The source of the amyl in this reaction is not difficult to discover ;for as above stated torrents of the usual products of its transformations (amylic hydride and amylene) were evolved during the operatiou; in fact it mas obvious that no inconsiderable portions of the zinc and amylic.iodide were occupied in the forniatioii of zincic iodide and amyl a con- Biderable proportion of the latter being ae uxsual transformed at the moment of separation into amylic hydride and amy- lene 2AyI + Zn” = Zn’? + Ay,. Meeting with this reaction as we have done only at the close of the above investigation we have not been able to ascertain whether or not it is one of general occurrence. It is true that we have not observed the formation of the fatty ethers in any of the foregoing reactions in which zinc and the iodides of the radicrils were employed; but the com-paratively low boiling-points of these ethers might easily have led to their being overloolred.We consider however this reaction of so much importance that we shall at once endeavour to ascertain whether or not it occurs in the other homologous cases giving rise to acetic ether in the case of VOL. XXII. F FRANKLAND AND DUPPA’S REBEARCBEB methylic iodide and to propionic ether where ethylic iodide is employed. We have already stated that the constitution of the acids of the lactic series has been the aubject of fruitful controversy amongst chemists. In this discussion widely different opinions have been advanced some have assigned to lactic acid the formula (C,H,,O,) and attributed to it a bibasic character; some have reduced this formula to C,H,O,.stilt retaining for the acid the game degree of basicity ; whilst others again have regarded it as monobasic and assigned to it the lower formula. This controversy respecking the constitution of an acid so intimately rglated to several of the most important families of organic compounds has been the incentive to numerous and highly important researches which have thrown vahmble light not merely upon the structure of the lactic series itself but also upon that of organic families allied to this series. Amongst the espeiimental investigations which have con- tributed to the elucidation of this subject we beg leave to refer to those of Wurtz,* Ulrich,f StreckerJ Briining,$ Perkin and Duppa.11 Again Wurtz Perkin Kekuld and especially K o1 be have by their acute theoretical.speculations most ably supplemented direct investigation. Unfortunately these researches and discussions were to a great extent limited to two members of this serieB viz. lactic and glycollic acid and this circumstance necemaril y furnished a comparatively small bask upon which to build purely theo- retical speculations. We are therefore not without hope that with the addition of the numerous members of this series described in the foregoing pages and with the light thrown upon them by their synthetical production we have reached a new stage in the inquiry whence a more extensive prospect may be obtained. Before proceedjng to take a survey of the new field thus opened up it is necessary fnst to call spacial attention to a negative or chlorous organic radical intimately connected with the compounds above described.* Cornptes Rendus vol. lii p. 1067. 5 Ann. Chem. Pharm. vol. xci p. 862. I-Ann. Chem. Pharm. vol. cix p. 271. 5 Ibid vol. civ p 191. II Ihid. vol. cviii p. 113. 59 ON ACIDS OF THE LACTIC SERIES. The Radical Oxatyl. An inspection of the above a?zd following formule for acids of the lactic series shows that through all the changes of the lactic acid type giving rise to the various species of acids men- tioned below the group COHO remains unaltered. We have also shown that the same group maintains its individuality unimpaired throughout the acetic and acrylic series of acids ; in fact it is the presence of this group which impresses upon an organic compound the acid character.We believe therefore that its claims to be considered a compound radical are at least equal to those of any other group of elements to which that term has been applied. We propose for this radical the name oxatyP-a word recall- ing at the same time its acidifying power aid its coii-nexion with oxalic acid which ip the isolatcd molecule of this radical {EE* Oxalic acid. We have in fact experimentally proved above that when ethylic oxalate is acted upon by nascent arnyl it is converted into ethylic caproate + {COEto {CBuH -COEto CBuH -{~~k~~ Ethylic oxalate. Amyl. Ethylic caproate. Oxatyl is closely related to cyanogen the two radicals pass-ing into each other in a host of reactions ; heme the production of cyanides from the ammonium salts of the fatty acids on the one hand and the syathesis of acids &om certain cyanogen compounds on the other-a reaction which was first pointed out by Kolbe and Frankland,? and has of late yielded such magnificent results in the hands of Maxwell Simpson and of Kolbe and Hugo Muller.5 Oxatyl would.obviously be the most appropriate name for this radical. ha& it not already been applied to the two compounds CO and C,O,. vhilst tbis paper is passing through the press we find that the radical oxatyl has already been fully recognized by Bu t 1e r o w. t Memoirs of Chem. So .vol. iii (1847) p. 386. ++ Philosophical Transactions 1861 p.61; and Journ. Chem. SOC. vol. xviii p. 331. 3 Jonm. Chem. Soc. vol. xvii p. 109 F2 FRANKLAND ANL DUFPA’S RESEARCHES {;g;* Cyanogen. The researches of these chemists prove that the introduction of cyanogen into an organic compound and its subsequent transformation into oxatyl converts that compound into an acid or if already an acid increases its basicity by unity for each semi-molecule of oxatyl so developed this result being apparently quite independent of the position of the oxatyl in the molecule. The semi-molecule of oxatyl as 1he above molecular formula Bhows may be regarded as methyl (CH,) in which two atoms of hydrogen have been replaced by one of oxygen and the third br hydroxyl (Ho). The individualizing of this group confers upon the formula of most of the great families of organic com- pounds a simplicity hitherto unattainable without ignoiing their atomic constitution.The passage from one organic family to another thus becomes a mere substitution of the hydroxyl con- tained in oxatyl by other radicals either simple or compound. When for instance it is replaced by the peroxide of a metal the acid of which the oxatyl is a constituent becomes converted into a salt thus Sodic acetate.. .. Barb acetate .. *f CONao Sodic rJuccinate .. ‘2’4~0Nao* co Baric succinate .. ..C,H,COBao”. With the hydroxyl replaced by methoxyl ethoxyl &c. an ethereal salt is produced as Ethylic acetate . a COEto Ethylic succinate .. ’‘‘2%COEto‘ CHHo (COEt 0) Ethylic citrate CH(C0Eto) .a. CH2(COEto) ON ACIDS OF Tm LACTIC SERIES. When the hydroxyl is replaced by hydrogen an aldehyde or an aldehydoid acid is the result. Thus Aldehyde .. .. COH Glyoxylic acid . '* {COHO* Again if a basylous monad radical take the place of the hydroxyl a ketone is formed Further if chlorine bromine &c. replace the hydroxyl a haloid compound of the so-called 64 acid radical " is the result Acetylic chloride .. ** {E%r cocl Succinylic chloride . ''C2H4COCy Again if the hydroxyl be replaced by oxygen an anhydride is formed Acetic anhydride Succinic anhydiide . . C2H:g0. And finally if replaced by amidogen an amide or amido-acid results t Succinamide .... It may be objected that the groap of elements which is thus invested with radical functions lacks one of the fbndamentat characteristics of a radical by its proneness to change ; but the -characteristic of perRistency is exhibited by the commody FRANKLAND AND DUPPA'S RESEARCHES received radicals in a very varied degree; and even methyl itself which certainly possesses it in the most marked manner readily permits of its hydrogen being replaced by chloriue or bromine on the one hand and by sodium on the other. All compound radicals are purely conventional groupings of elements intended to simplify the expression of chemical clmnge ; and inthis respect we believe hhe' group oxatyl enter- ing a8 it does into the constitution of nearly every organic acid has as valid a claim to a distinct name as the most univer- sally recognized radicals.Its admission relidem possible the following very simple expression of the law gweriiing the basicity of nearly all organic acids :-An organic acid containing n semi-molecules of oxatyl is n-basic. Classijcation of the Acids of the Lactic Series. We propose classifying all acids of thelactic seriea at present lciiown or which could be obtained by obvious processes into the following eight divisions :-1. Normal Acids. 2. Etheric Normal Acids 3. Secondary Acids. 4.Etheric secondary Acida 5' Normal Olefine Acids. 6. Etheric Normal Olefine Acids. 7. Secondary Olefine Acids. 8. Etheric Secondary Olefine Acide.1st. AforinaZ Acids.-A normal acid of the lactic seriea may be aefined as one in which an atom of carbon is united with oxatyl hydroxyl and at least one atom of hydrogen. The general formula of theae acids is therefore + In this formula R may be either hydrogen or any monad alcohol raclicd; and the number of acids possea&g the same atomic weight znd belonging to this division is determined by the + umber of isomeric modifications of which the radical R irs susceptible. Thus of the acids containing two three or four ON ACIDS OF THE LACTIC SERIES. atoms of carbon there can be only one of each belonging to this division because these acids cannot contain an alcohol ra&cal higher in ihe eeries than ethyl which is not susceptible of isomeric modification ; but a normal acid containing propyl can have one isomer in this division the two acids containing respectively propyl (CEtH,) and isopropyl (,CMe,H).For acids of t'his division containing normal alcohol radicals only the following general graphic formala may be given :-In the case of glycallic acid n = 0. The following are the acids at present known belonging to this division":-Gclgcollic acid. *. Lactic acid . . 0. CEtHHo Oxybutyric acid (COHO " CBuHHo Leucic acid . . .. .* {COHO 2nd. Etheric Normal Acids.-An etheric normal acid of the lactic series is constituted like a normal acid but contains a monad organic radical chlarous or basyloue in the place of the hydrogen of the non-oxatylic hydrosyl.The following is there-fore the general formula of these acids in the graphic formula n as before may = 0 * Since the above was written Fittig has produced valerolactic acid the rational formula of which ia doubtlese 1~~~Ho.-April 29th 1866. FRANKLAND AND DUPPA’S RESEAROHES The number of possible isomers belonging t.0 this division is very great; for in addition to those of which the normal acids + containing R of the same value are susceptible a host of others + + must result from the complementary variation of R and R. The lowest member of the division metliylglyuollic acid (isomeric with lactic acid) is the only one incapable of isomeric modifi- cation. The following examples mill serve to illustrate the constitu- tion of the acids belonging to this division :-Methylglycolh acid .... {;;go. Ethyl-lactic acid ,. .. Aceto-lactic acid .. .. . {~~;~Aco* . 3rd. Secondary Acids.-A secondary acid of the lactic series is one in which an atom of carbon iti united with oxatyl hydroxyl and two semi-mobcubes of an alcohol radical. The general formula of these acids is I 0.. .......@.............. ............@ or ..... . . .. . 1 I @=@ Ina I 8 In the graphic expression the values of n and m may differ but both are positive integers and neither may = 0. In the + symbolic formula R must be a monad alcohol radical. All the known members of this division me described in the foregoing pages. The following examplea will serve to illnstrate their constitution :-Dimethoxalir acid,... {ggO. * ACO= peroxide of acetyl C2H302. ON ACIDS OF THE LACTIC SERIES. ti5 Ethomethoxalic acid . . { ~~~~Ho. Diethoxalic acid . . The number of acids possessing the same molecular weight and belonging to this division is determined first by the comple- mentary variation of the two alcohol radicals and secondly by the number of possible isomers of these radicals. The two lowest terms of the series are alone incapable of isomeric modi- fication by either of the causes mentioned. 4th. Etheric Secondary Acids.-These acids stand in the same relation to the secondary as the etheric normal to the noimal acids ; they consequently contain a monad organic radical in the place of the hydrogen of the non-oxatylic hydroxyl.The following is therefore the general formula of these acids :-We have obtained acids belonging to this division which we hope to describe in an early communication. 5th. Normal Olejne Acids.-A normal olefine acid belonging to the lactic series is one in which the atom of carbon united with ovatyl is not combined with hydroxyl and in which the atom of carbon united with hydroxyl is combined with not less than one atom of hydrogen. The following are the general graphic and symbolic formule of the acids belonging to this division:-In both these formula n mmt be a podtive integer and can- F'RANELAND AND DUPPA'S RESEARCHES + nut = 0 but R may be either hydrogen or a monad alcohol radical.The olefines of these acids may belong to either the ethylene or ethylidene series. The following are the only acids at present known belonging to thie division :- Paralactic acid .. lcofio Paraleucic acid .. {ig. We give the name paraleucic acid to the acid obtained by Lippmann* in acting with phosgene gas upon amrlene. Thk body has not yet been completely investigated ; Lippmann regards it as identical with leilcic acid but as it is produced by a reaction exactly homologous with that by which paralactic acid is formed we believe it will be found to differ slightly fiom leu& acid ag paralactic does from lactic acid. The number of isomers in thia division will obviously depend first + upon the complementary variations of R and (CH2)n; secondly + upon the isomeric niodifications of which R is susceptible; and thirdly upon the isomeric modifications of (CH,),.6th. Etheric Normal OleJne Acids.-These acids differ from the normal olefine acids only in having the hydrogen of the non-oxatylic hydroxyl replaced by an organic radical positive or negative ; therefore their general formula is Aa in the fifth division n must be a positive integer and cannot + = 0 whilst R may be either hydrogen or a monad alcohol + radical; but R must be a monad compound radical either acid or alcoholic. * ban. Ch. Phm. cxxix..81. ON ACIDS OF THE LACTIC SERIES 7th. Seconda?y Olt$ne Acids.-A secondary olefme acid of thk series is one in which the atom of carbon united with oxatyl is not combined with hydroxyl and in which the atom of carbon united with hydroxyl is also combined with two monad alcohol radicals as shown in the following formulae :-In both of these formulae n must be a positive integer and t cannot = 0 and R muat be a monad alcohol radical.8th. Etheric Secondary Olejne Acids.-These acids are related to the secondary olefine acids in the same way as the sixth division to the fifth. No member of the seventh or eighth divi-sion has yet been formed. Isomerzsrn in the! Lactic Series. The members of the lactic series may be defined as acids con- taining one aeini-molecule of oxatyl the fourth bond of the carbon of which is united with the carbon of a basylous group containing one semi-molecule and one only of hydroxyl or of the peroxide of a radical either alcoholic or acid.The following examples ex- pressed in the grapbic notation of Crum Brown,' will serve to illustrate this definition. * Edinburgh Phil. Trans.for 1864 p. 707. It is much to be desired that chemista should employ these graphic formnlse in all caaes where they wish to express the mode in which they suppose the elements of a chemical compound to be combined. It is often extremely difficult to trace in aymbolic formulae the exact meaning which an author attaches to the grouping of letters ;in graphic formnlse no sudl difficulty can arise ; and we therefore think that the u~e of these formulse where constitutional expressions are intended will greatly tend to clearness and precision.It is scarcely necessary to repeat Crum Brown's remark that such formulse are not meant to indicate the physical but merely the chemical position of the atoms. For the pur- pose of rendering the graphic more easy of cornpalison with symbolic formuh we hve sometimes dissected the former into their constituent radieals by dotted lines 8s above. Thisdissection whilst assisting the eye in reading the f&nulm cannot fail to sugest the for the most part purely conventional character of such radicals. FRANKLAND AND DUPPA'S RESEARUHES Acids of the Lactic Series. 0 I io ................. -g-@ i ....I ............ ....1 ............ q" I ;....J ............ 69 Lactic acid. Methyl-lactic acid, @ Aceto-lactic xacid.The synthetical study of the acids of this series affords an insight into numerous and interesting cases of isomerism which have hitherto received at best but. a very imperfect explanation. Commencing with the lowest member of the series we have for glycollic acid the formula- @ 1 ...,........I ............ An inspection of thia foimula shows that gIycollic acid admits of no iaomeric modification except with a total change of type unless a difwent value be assigned to the individual bonds of an atom Of carbon. The part of the formula below the dotted line represents oxatyl which a8 we have already shown cannot be altered without sacrificing the acid character of the compound there remains therefore only the part of the foimula above the dotted he which admits of the following modification :- ON ACIDS OF THE LACTIC SERIES.The acid represented by the formula so modified no longer comes within our definition of the lactic series. It is carbo- meth-ylic acid and differs essentially from glycollic acid and the lactic series in general inasmuch as the carbon of its chlorous radical oxatyl is linked to the carbon of the basylous radical by oxygen.* There being no decisive evidence that homolactic acid differs from glycollic acid experiment and theory both agree in asserting that the formula C,H40 represents only one acid in the lactic seriea. Proceeding now one step higher in this series we have in the formula of lactic acid an expression capable of the following three variations without quitting the lactic type :-* Bearing this constitution of carbomethylic acid in mind we have only to go one step further in order to perceive the constitution of carbonic acid itself and the anomalous basicity of that acid ;for if in the above grapbic formula for carbome-thylic acid we replace the methyl by hydrogen we have 0 @-&El I 69 I @=@ h 1 0 Carbomethylic acid.Carbonic acid. It is thus evident that our radical oxatyl when united with hydroxyl haa sJlfEcient chlorous power to produce a feebly bihasic acid but inasmuch as carbonic acid is not included in the category of organic acids it forms no exception to the law above enunciated. FRANKLAXI3 AND DIPPA’S RESEARCHES No.1. No.2. No.3. 69 I ? @-@-@ I Or expressed aymbolically No. 1. INo. 2. No. 3. All the acids represented by the above formulae are known. The first expresses the constitution of lactic acid which be- longs to the normal diviaion ({gig:’) of the series described at page 62; the second shows the atomic arrangement of paralactic acid whilst the third representa methyl-glycollic acid. The proof that the first two of these acids are so con-stituted is afforded by the beautiful synthetic processes for their production devised by Wislicenus* and Lippmann.7 The first of these chemists has shown namely that ethylidene cyanhydrate is converted by ebullition wikh potash into a salt of lactic acid whilst ethylene cyanhydrate is transformed under similar circumstances into paralactic acid.Lip p m a n n has also rJhown that by the action of phosgene gas upon ethylene paralactic acid is produced. Now the formation of ethylidene or rather of its compounds scarcely leaves a doubt that this body if isolated would have the following atomic constitu- tion :-* Ann. der Ch. nnd Pharm. Bd. cxxviii. 5. 1. + Ibid. Bd. cxxix. S. 81. Crum Brown has already pointed out this relation between lactic and paralactic acids as well as the formula of ethylene given below.-Edinburgh Phil. Trans. for 1864 p. 712. ON AUIDS OF THE LACTIC SERIES it would consist of a gemi-molecule of methyl united with an atom of carbon two of whoge bonds satisfy each other Thus the for- mation of ethylidenic dichloride from aldehyde and phaspho~ chloride takes place as follows :-Aldehyde.Ethylidenic dichloride. the oxygen in the aldehyde being simply replaced by chlorine. There now only remains one possible formula for ethylene vie. :-Such then being the comtitution of ethylidene and ethylene it follows that the former ought to give riBe to an acid of the constitution shown in formula No. 1 whilst ethylene should produce an acid agreeing with formula No. 2. The acih actually produced from these sources are lacti;? and paralactic acids; hence we believe No. 1to be the constitutionalfoimula of lactic acid and No. 2 that of paralactic acid a conclusion which har- monizes perfectly with all the reactions in which the production of these acids can be traced.ThuB in the formation of lactic acid by the oxidation of propylic glycol,* we have CMeHHo CMeHHo+ oqm {COHO LL L Propylic glycol. Lactic =id. Again the production of this acid fiom ethylidenic cyanhy- drate * Wurtz Ann.der Chem. und Pharm. Bd. cv. 8. 206. fCH.Ho '24-= FRANKLAND AND DUPPA'S RESEARCHES CH {gEboCy -k OKH OH = {CHho(C0Ko) + NH,. Ethyli denic Potassic lactate. cyanhydrate. The formula given for potassic lactate in this equation is only apparently different in type from that previously used for lactic ac.id since In Ulrich's" interesting reaction by which chloropropionic acid is transformed into lactic acid we have the following change :-Chloropropionic Potassic lactate. acid. The production of lactamic acid (alanin) and that of lactic acid from the latter by the action of nitrous acid are also dearly confirmatory of the above view.{ g$NH,) + Cg"'+ OH + HC1 = {Et&:(NH2) + NH,Cl Ammonic Hgdrocyanic Lactamic add (alanin). aldehyde. -acid. Lacgmic acid (alanin). Nitrous acid. Lactic acid. Not the least interesting reaction illustrative of the constitu- tion of lactic acid is the formation of this acid by the action of nascent hydrogen upon pyruvic acid recently described by W is1ic enu s.7 CMeO CMeHHo (COHO + = {COHO Pyruvic acid. Lactic acid. By an analogous reaction glyoxylic acid which we regard as the next lower hornologue of pyruvic acid has been transformed by D e bust into glycollic acid. * Ann. Chem.Pharm. cix. 271 t. Ibid. cxxvi. 226. $ Ibid. cxxvii. 145. ON ACIDS OF THE LACTIC SERIES. CHO {::em {COHO -k H2 = Qlyoxylic acid. Glycollic acid. In a similar manner it can be demonstrated that the above formula No. 2 expresses the constitut<ion of paralactic acid which belongs to the fifth or olefine division of these acids C~~HH~ C~HH~ { (cH,),(cIH~) 01’ { (((% . That paralactic acid possesses this constitution is proved first by its production from cyan-hydric glycol CH,Ho {:2$&) + KHo + OH = CH2 + NH ; LOKo Cyan hydric L Potassic glycol. paralactate. and secondly by its formation from phosgene gas and ethylene {g2+ coc1 = CH,(COCl) ; Ethylen;. PhorJgene. Chloride of B chlorpropionyl.CH,(COCl) -t 30KH = {~~~oKo) + 2KC1 + OH,. Chloride of Potaaeic B chlorpr opionyl . paralactate. By the action of waterupon the chloride of p chIorpropiony1 a body of the composition of chloropropionic acid results; but inasmuch as this body yields paralactic acid by ebullition with potash whilst chloropropionic acid gives under the same cir-cunzstances lactic acid it follows that the former chloro-acid must be isomeric and not identical with the latter. Now although the formula of propionic acid does not admit of any isomer yet that of chloropropionic acid does as is Heen in the following graphic formula :-VOL. XXII. FRANKLAND AND DUPPA’S RESEARCHES No. 1 Ro. 2. I @-@-@ I A comparison of these fomdai! with those of lactic and para-lactic acids (page 70) shows at a glance that No.1 is the chloropropionic acid which yields lactic acid whilst No 2 isiso-chloropropionic acid which by the substitution of its chlorine by hydroxyl must yield paralactic acid By the action of nascent hydrogen both isomeric chlorides will obviously produce the same propionic acid. The cause of the isomerism of methyl-glycollic acid (No. 3 page 70) is so obvious as to require no further explanation. Proceeding to the next higher stage in the series mch is the rapid increase of isomerism that we now encounter no less than eight possible iBorners all within the lactic family. Etheric normal. Normal. Secondary. c No. 1. No. 2. No. 3 rn CMe Ho CH Eto {EEHO* (cod0 {co~o {,EEMe0* Normal olefine.-Etheric normal olefine. No.5. No.6. No. 7. No.8. CH,Ho CH2Ho CMeHHo CH,Meo {% ’ {EE {ao coho {%lo ’ ’ Of these acids Noa. 1 2 and 3 are known. No. 1is oxybu-tyric acid; No. 2 is dimethoxalic acid which is probably identical wit11 Stadeler’s acetonic acid.* On this assumption the for- mation of the latter by the action of hydrocyanic and hydro- chloric acids upon acetone is easily intelligible. * Ann. Ch. Pharm. cxi 320. These acids have since been proved to be identical. ON ACIDS OF THE LACTIC SERIES. {:the + CN"'H + 204 + HCl = (COHO CMe2Ho + NVH4Cl. Acetone. Acetonic or dimethoxalic acid. The properties of acetonic acid and its salts aB described by Stadeler agree well with those which we have observed in dimethoxalic acid and its compounds both acids evolve an odour of acetone on being heated with potassic hydrate and are decomposed without blackening by concentrated sulphuric acid with evolution of much gas.The third of the above formulae is obviously that of Heintz's ethyl-glycollic acid.* The origin of Wu rt z' s butylactic acid which was prepared by an analytical process does not permit of any safe conclusion being drawn as to its constitution. Of the possible acids containing five atoms of carbon only one (the ethomethoxalic acid described a.bove) is kn0wn.t Of acids containing six atoms of carbon three are known to which we assign the following formulae?- CBuHHo Leucic acid . . .. {COHO Diethoxalic acid . .Paraleucic acid . . me {% The above formula for leucic acid is founded upon Lim-prich t'st interesting reaction for the spithetical production of this acid from valeric aldehyde and hydrocyanic acid. Kolbe has shown that valeric acid contains butyl; conse- quently valeraldehyde has the constitution expressed by the C Bu formula and Limpricht's reaction may therefore be explained by the following equation * Pogg. Ann.cix. 331. ( { ErgH0), f-Valerolactic acid just diacovered by Fittig forms a second Its isomerism with ethomethoxalic acid is proved by its melting-point which ia 80°C. whilst ethomethoxalic acid fusea at 63"C.-April 29 1866. $ Ann. Ch. Pharm. xciv 243. FRANKLAND AND DUPPA'S RESEAROHES Ammonic Leucin. valeraldehyde.Such being the rational formula of leucin it8 transformation into leucic acid by nitrous acid determines the constitution of leiicic acid {Egy'NH') + N"'OH0 ={COHO CBuHHo + OH + N,. Leucin. Nitrous acid. Leucic acid. We entertain no doubt of the isomerism of leucic and dieth- oxalic acids although we have not yet been able to observe any substantial difference between them ;both acids melt at nearly the same temperature (leucic acid at 73"C. and dieth- oxalic acid at 74O.5 C.). Waage* states that zincic leucnte requires 300 parts of water at 16" for its solution whilst we find that zincic diethoxalate requires 302 parts at 16" C-Doubtless the study of the products of the tr6nsformation of these acids will reveal the difference existing between them we are at present preparing leucic acid for this purpose.We have also mentioned in the experimental part of this paper that diethoxalic acid prepared from methylic diethoxalate yields a silver-salt which differs from that obtained with the acid horn ethylic diethoxalate ; and we have even noticed indications of a third synthesised isomer ; but we reserve the further inquiry into the nature of these acids for a future communication. On the Proximate Analysis of the Acids of the Lactic Series. The investigations recorded in the foregoing pages show that the division of acids of the lactic series which we have termed gecondary acids is derived from oxalic acid by the substitution of two aemi-molecules of monad alcohol radicals for one atom of oxygen in that acid.This substitution destroys one of the semi- molecules of oxatyl in oxalic acid thus reducing the latter from a dibasic to a rnonobasic acid. This theory of the structure of the secondary acids so unmistakeably indicated by the mode of their formation we have also extended to the normal acids f Ann Ch.Pharm. cxviii 295. 0s ACIDS OF THE LACTIC SERIES. 77' Which are thus regarded as derived &om oxalic acid bythe replacement of one atom of' oxygen in the latter either by hydrogen alone it^ in glycollic acid or by one atom of hydrogen and one semi-molecule of a monad alcohol radical :-{EE {EkP {::g:Ho Oxalic acid. Qlycollic acid. Lactic acid. Hitherto we have advanced only synthetical evidence of this constitution ; but the question presents itself if the radicals indicated by our hypothesis really exist in these acids can they not be again disentangled from the complex molecule either in the coiidition in which they entered it or at all events in the form of well recog~zed derivatives ? Such analytical evidence although possessing far less weight than synthetical may still be of service as corroborative testimony.We will therefore show how such a proximate analysis of these acids can be accomplished and for this purpose we will first endeavour to demonstrate that if in a chain of carbon atoms any two be united by two bonds of each the remaining atoms being united to each other by one bond only the chain is more liable to rup-ture at the point of double junction than at any other.We have shown how in dimethoxalic acid a weak link of this kind can be developed;* for if' dimethoxalic ether be treated with phosphorous chloride it is transformed into ethylic methacry- late the acid of which contains two atoms of carbon in the condition just indicated. The nature of this transformation and the link in the chain which is thus weakened are ahown in the following graphic formulae :-W U Dimethoxalic acid. Methacrylic acid. # Journ. Chem. SOC.vol. xviii. p. 141. FRANKLAND AND DUPPA'S RESEARCHES If methacrylic acid be now heated with potash the acid molecule breaks up at the place indicated by the dotted line with the production of propionic and formic acids :-L Met,hacrylic Potassic Potassic acid.propionate. forplate. Q @ Propionic acid. Formic acid. Thus one of the atoms of methyl originally introduced into oxalic acid is now extracted in the shape of its well-known derivative formic acid. We have proved by synthesis that propionic acid is methacetic acid { gEiy2 ; but it still remains to extract this second atom ofmethyl fiom it. For thirs purpose we might transform the propionic acid into chloropropionic acid and the latter into ethylic lactate by well-known processes when by repeating the reactions with phosphorous chloride and caustic potash above described the second atom of methyl like the first ought to be eliminated as formic acid; but unfor-tunately the reaction with terchloride of phosphorus although so easy with a secondary acid fails when applied to a normal acid of the lactic series and we are therefore diiven to seek other means of obtaining the end in view.It is however only necessary to avail ourselves of the beautiful reactions of K 01b e* in order to extract the remaining atom of methyl in its integral farm. Thus if the lactic acid derived a8 above described be submitted to the action of electrolytic oxygen it is transformed into carbonic acid and aldehyde {gtg:Ho + 0 = CMeHO + COHO,. L htic acid Aldehyde. Carbonic acid. * Apn Chmn Pbm. cxiii 244. ON ACIDS OF TEE LACTIC SERIES. It will be oberved that one of the atoms of oxahyl in the original oxalic acid ({g",::) is here eliminated as the well- known derivative carbonic acid.The aldehyde thus obtained which contains the methyl sought for must now be oxidized to acetic acid; and it then only remains to resort once more to electrolytic oxygen to liberate the methyl together with the remaining atom of oxatyl originally present in the oxalic acid 2{gzfio + 0 = {:2+ 2C0 + OH,. Acetic acid. Methyl. We tabulate below the materials used in the synthesis of dimethoxalic acid side by side with the products obtained bY the analysis of that acid :-Materiala for Synthesie. Results of Analysis. ' I. 11. -\ I. 11. \ 2COH0,. Carbonic acid. CH,. Methyl. COHHo. Formic wid. Oxalic acid. Methyl. In like manner the radicals contained in the other acids belonging to the normal and secondary divisions of the lactic series can be extracted whilst it has already been proved by Butlerow" that etheiic normal acids when treated with con- centrated solution of hydriodic acid yield up as iodide the alcohol radical which in these acids is linked to carbon by oxygen; thus in the case of ethyl-lactic acid Ethyl-lactic Lactic acid.Ethylic acid. iodide. The olefine acids are as yet too little known to allow of their constitution being thus analytically investigated. These acids do not derive from oxalic acid by substitution alone but by simultaneous- addition of an olefine. They may in fact be regarded as standing somewhat in the same relation to the * Ann. Chem. Pharm. cxviii 326. FRANKLAND AND DUPPA'S RESEARCHES ETC. normal acids as the polyethylenic glycols occupy with regard to the normal glycols as seen from the following comparison :-{E:::* Glycol.{&* (EiP* {:yo. CH,Ho Glycollic acid. COHO CH,Ho P&dactic acid. Diethylenic glycol. We beg to append the following summary of conclusions to which our investigations have conducted us :-1. All acids of the lacti series are essentially monobasic. 2. These acids are of four species viz.,normal secondary normal olefine and secondary olefine acids; and each of these Bpecies has its own etheric series of acids in which the hydrogen of the hydroxyl contained in the positive or basylous constituent of the acid is replaced by a compound organic radical either positive or negative. 3.The normal acids are derived from oxalic acid by the re- placement of one atom of oxygen either by two atoms of hydrogen or by one atom of hydrogen and one semi-molecule of an alcohol radical. 4. The secondary acids are derived from oxalic acid by the replacement of one atom of oxygen by two semi-molecules of monad alcohol radicals. 5. The olefine acids are derived from oxalic acid by a like substitution of two monad positive radicals for one atom of oxygen with the insert'ion of an olefine or dyad radical (CnH2J between the two semi-molecules of oxatyl. 6. The acids of the lactic series stand to the acids of the acetic series in the"very simple relation fist pointed out by Kolbe viz. that by the replacement by hydrogen of the hydroxyl ethoxyl &c.contained in the positive radical of an acid of the lactic series that acid becomes converted into a member of the acetic series. 7. The acids of the lactic series stand in an almost equally simple relation to those of the acrylic series as is seen on corn-paring the following formulae :-Lactic acid. Acrylic acid.

ISSN:0368-1769    

DOI:10.1039/JS8692200028

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

81 V1.-On the connection between the Mechanica 2 Qualities of Malle-able Iron and Steel and the amount of P7kosphorus they contain. By B. H. PAUL,Ph.D. IThas been customary to consider the presence of veiy small amounts of phosphorus or sulphur in malleable iron and more especially in steel as being among the circumstances most pre- judicial to the qualityof the metal. This opinion is generally expressed in chemical text-bwks and metallurgical treatises ; but there appears to be much uncertainty as to the actual amounts of these substances which are sficient to cause dete- rioration of the quality of malleable iron or steel. Phosphorus is considered to render the metal weak and what is technically termed ‘‘(cold short.” As regards steel it has recently been stated by an eminent metallurgist* to be a fact at least as well established and as generally accepted as any relating to metallurgy that much less than about 0.3 per cent.of phos- phorus produces a decided and injurious effect. There is probably little reason to question the general ac- ceptance of the opinion that a very small amount of phosphorus exercises a prejudicial influence on the quality of steel but at the same time there does not appear to be any definite or satis- factory evidence that this opinion is well founded nor any sufficient- proof that the observed inferiority; in certain cases of the steel or malleable iron made from phosphuretted pig iron is really due to the presence of phosphorus in the metal ; still less is there any reasonable explanation to be met with either aB to the way in which phosphorus affects t,he qualities of the metal or as to the state in which it may exist.In fact the view held in regard to this subject though based to Bome extent on experience of a limited nature is unsupported by any scientific evidence and it rests mainly on the fact that certain celebrated varieties of malleable iron and steel of very high quality are known to be either free from phosphorus or to contain only infinitesimal amounts of that substance rarely exceeding 5+TT in malleable iron and s&a in steel. The opinion that the presence of phosphorus affects inju-iiously the qualities of steel and malleable iron has lately * Dr. Percy (‘Times,” 7th January 1869.VOL. XXII. H 82 ON THE CONNECTION BETWEEN THE MECHANICAL received considerable support from the experience gained in the application Gf the Bessemer method of converting pig-iron for it has been found to be a coincidence which so fa as I am aware is invariable that pig-iron containing as much as 0.1 per cent. of phosphorus is unsuitable for working by that method. As there is no elimination of phosphorus effecteih by the Bessemer method this amount of phosphorus hm conse-quently been regarded as the maximum proportion which steel can contain without its quality being deteriorated. This con- clusion appears to be a generalization much wider than is justified by the f‘dcts observed for it is still questionable whether the coiiicidence between the presence of‘ a certain amount of‘ phosphorus and the inferiority of the steel may not be purely accidental and whether the .inferiority of steel made fiom phosphuretted pig-iron may not be due to mme other circum- stance than the presence of phosphorus.The probability of this being the case occurred to me some years ago when I had occasion to give special attention to this subject and quite recently an opportunity has offered itgelf for testing the suffi- ciency of the received opinion. Some considerable surprise has been excited by the publication of an analysis by Dr. Miller of a sample of so-called ‘‘ steel iron,” which gave the proportion of phosphorus as amounting to 0.292 per cent. while the results obtained by Mr. Kirkaldy in testing a large number of samples of this metal showed that it gave indications of very excellent quality in regard to tensile strength and ductility These results taken together with the amount of phosphorus indicated by Dr.Miller’s analysis as Being present in the metal appeared to be so inconsistent with the general opinion as to the influence of phosphorus in rendering malleable iron weak and “cold short,” that I thought a further examination of other samples of this metal would be desirable; for if phosphorus were really the cause of weakness and if it were that substance which rendered iron (‘cold short,” it seemed to me that the tensile strength of the metal wds precisely the character that should be most prejudicially influenced by the presence of such an amount of phoaphorus.If therefore the analysis of several bars of thk “steel iron,” which had been tested as to their tensile strength and gave results showing that this was con-siderable should at the Bame time indicate the presence of phoaphorus to any great extent it appeared to me that there QUALITINS OF MALLEABLE IRON AND STEEL ETC. would at least be some ground for questioning the opinion hitherto held as to the influence of that substance on the quality of iron and Some evidence that in regard to the amount of phosphorus which might exist in malleable iron and steel with- out affecting its quality something yet remained to be learnt either as to the state in which the phosphorus existed or as to the conditions by which any prtjudicial effects of its presence might be counteracted.With this object I obtained through the kindness of Mr. No yes portions of several bars of "steel iron," produced from various kinds of pig-iron all of which bars had been tested by Mr. Kirkaldy as to their tensile strength and other mecha- nical qualities. These samples were examined for phosphorus quantitatively with the following results :-No. of bar. Tensile etrength in pounds per square inch sectional area. Permanent exteudon of bar per cent. Kind of pigironproduced from. Amount of phosphorus per cent. 1,090 1,091 51,671 51,181 25 '5 24 -5 Clay Lane No. 4 pig."Stanton forgepiq BBB.+ Clay Lane No. 4 pig.*Stanton forgepig BBB.t '206 -271 1,660 52,014 26 -6 *311 1,320 51,593 28 *6 -203 1,147 1,251 1,342 51,597 46,547 52,842 23 *7 21 .o 26 *6 Glengarnock,{ so.2 pig.§Round Oak11 ButterleyTI *170 0144 *286 These results are perfectly in accordance with the isolated result obtained by Dr. Miller and they indicate I believe an average amount of phosphoius much larger than would have been generally considered to exist in malleable iron presenting such a degree of tensile strength as that assigned to these bars and so far as this character gerves to indicate the quality of the * Cleveland iron. t Northamptonshire iron. $ Welsh iron. 9 Scotch iron. 11 .Staffordshire iron. 7 Derbyshire iron. H2 ON THE CONNEUTION BETWEEN THE MECHANICAL metal it would appear to be very good. According to the deter- minations of tensile strength of bar-iron by Fairbairn,* Kirkaldy,f Napier,-$ and others it amounts in the very best kinds of iron (Swedish and Lowmoor) to about 58,000 lbs.per square inch sectional area on the average and ranges from 47,855 lbs. to 66,390 lbs. while the average permanent extension or drawing out of the bars which furnishes an index of the ductility of the metal and its consequent power to resist the influence of a shock amounts to about 24 per cent. and ranges from 20 to 28 per cent. The number of analyses here given is of course much too small to admit of any general conclusion as to the amount of phosphorus which may be present in malleable iron without affecting its general quality and applicability for the various pur- poses to which it is applied; but in any case as tensile strength is one of the most important qualities of iron and as a high degree of that character appears to be compatible with the presence of a considerable amount of phosphorus in the metal this fact has an interest in reference to the manufacture of iron horn the very abundant iron ores of this country which have been considered inferior to a great extent by reason of the amount of phosphorus they contain.There are also other facts which tend to throw some doubt on the received opinion as to the influence of phoephorus. Thus for instance I can state as the result of my own observation that throughout the whole iron districts .of Belgium the ores smelted contain on the average a very large amount of phosphorus; but notwith- standing this fact some very good malleable iron is produced there although none of the Belgium pig-iron I have met with will answer for conversion into steel or malleable iron by the Bessemer method.In addition to the bars of ‘‘ steel iron ” above mentioned I also obtained portions of two bars of cast steel which were similarly tested by Mi*.Kirkaldy and on analysis I ascer-tained the presence of phosphorus in them in the following amounts :-* British Association Reports 1856. .t. Transactions of the Institution of Engineers in Scotland 1858-9. $ Ibid. QUALITIES OF MALLEABLE IRON AND STEEL ETC. Tensile strength Pemanent Amount of No.of bar. in pounds per extension Kind of pig-iron phOSphOrU6 square inch per cent.produced from. per cent. sectional area. ay Lane No. 4 1,077 80,916 3 -3 pig Stanton -240 p1 forge pig BBB. Clay Lane No. 4 1,082 106,602 13*7 pig Stanton *241 forge pig BBB. According to the observations of F nirbairn Kirkaldy and Napier the average tensile. strength of cast-steel bars and plates is about 100,000 lbs. per square inch of sectional area and it ranges from 75,594 lbs. to 132,909 lbs. according as the metal is hard or soft The corresponding permanent extension amounts on the average to 8.7 per cent. and ranges from 31 to 19-8per cent. In regard to mechanical qualities therefore the bars of cast steel here referred to come within the range of variation observed in high class steel. At the same time the amount of phosphorus in this cast steel is very much more in excess of’ the reputed maximum amount that can exist in steel of such quality as is indicated by these mechanical tests than it is in the case of the bars of ‘‘ steel iron,’’ and it is about tenfold -as much as is stated to be preseKt in the best kinds of steel.These results are therefore interesting in so .fax as they show that the presence of such an amount of phosphorus in steel does not ne’cessarily interfere with its possessing a high degree of tensile strength which is one of the most important qualities for many of the purposes to which steel is now being applied. It must be stated here that the samples of iron and steel analysed were produced by what is known as the Heaton method of converting pig-iron by means of alkaline nitrate.I am unable at present to give any results which wouldserve to indicate the state in which the phosphorus may exisrt in the samples of iron and steel above referred to; but this seems to be a question deserving of inquiry for as it is considered t80be an established fact that steel or ironmade by the Bessemer method cannot contain at the utmost. more than +&v part of phosphorus if its quality be good the existence of such a much larger amount in the samples I have analysed would seem to indicate the possibility that if phosphorus be injurious in some cases Kt5 MALLEABLE IRON AND STEEL ETC. still under certain coniiitions at least it may be present without any such effect. It is my intention to carry out a complete exaiiiination of theae samples with the object of elucidating if possible this question.The analytical method by which the separation of phosphorus was effected in these analyses; was that by means of molybdic acid and with the exception of the length of time required for the successful application of this method it is one-which I believe presents great advantages especially for the deter-mination of small amounts of phosphorus. The chief pre- cautioiis I have fwund necessary to be observed are to avoid the presence of any great excess of free acid in the solution to be tested; to haw this solution as concentrated as possible before adding the molybdic solution and then to give amply sufficient time for the perfect separation of the yellow precipitate.This separation is much facilitated by heating the liquid; but since arsenic acid reacts in the same manner as phosphoric acid and gives a similar yellow precipitate when the liqiiid is heated to near the boiling point it is desirable not to heat it much above 4OoC. At least 24 hours should be allowed for the separation of the precipitate and then it may be collected on a filter and washed with wat.er containing about 1 per cent. nitric acid and a mere trace of molybdate of ammonia in which the yellow pre- cipitate-containing only about 4 per cent. phosphoric acid-is 80 slightly soluble that the estimation of phosphorus is not sensibly affected. For the determinat3on of phosphorus 01-phosphoric acid the weighing of the yellow precipitate which may contain arsenic acid and silica is less to be depended upon than converting it into phosphate of magnesia arid ammonia by dissolving with ammonia and precipitating with a magnesia salt.The ammonia phosphate may either be weighed after drying at loPC. and then tested for silica and arsenic or ignited and the pyro- phosphate weighed as usual. This method of estimating phosphorus in iron and iron ore i%I believe much more to be depended on than any of the other methods hitherto adopted with some of which there is much iisk of an imperfect separation of t,he minute quantities of phosphoric acid from the disproportionately large quantity of iron.

ISSN:0368-1769    

DOI:10.1039/JS8692200081

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

87 TIT.-On the Chemical Composition of Canauba Wax. By NEVILSTORY-MASKELYNE, M.A. THEwax-like coating which protects the leaves and fruits of many plants has received little attention at the hands of chemists mainly probably because its quantity is small and the difficulties of collecting it in many cases almost insuperable. In Canaiiba wax however commerce supplies us with a material directly derived from a plant which furnishes such a wax in appreciable quantities. This vegetable wax is the pm- duct of a palm the Copernicia cerifera of botanists the'canauba tree of the Brazilians. It grows to a height of 20 ta 40 feet and when young its trunk is covered with leaves which however in the older plants are found only at its summit in a globular cluster.Its sap yields an amylaceous food its wood is a valuable timber while its younger leaves furnish in the gIaucous coating that protects them the wax-like body the chemical nature of which the following investigation may con-tribute to elucidate. The leaves are ghaken after being detached from the tree and the wax which they yield to the amount of some 50 grains per leaf is melted into a mass. In this state itpis a pale yellow body with a f'a.int tinge of green considerably harder at ordinary temperatures than bees- wax and from the descriptions of the wax made from the noble palm the Ceroxylon AndicoZa of the Cordilleras it would seem to be also harder and less resinous than this latter body. The specific gravity of Cawaiiba wax is 0.99907 and its melt-ing point is about $4"C.On being incinerated it yields 0.14 per cent. of ash for the most part consisting of dica and iron with some sodic chloride. Many trials were made as to the best way of breaking this body up into its cmstituent compounds. The following methods were those ultimately adopted for the purpose. A quantity of tlie crude substance was boiled with alcoholic solution of potash containing one-sixth of its weight of alkali till the liquid became clear when the spirit was distilled off. The residue in which are contained the saponified products STORY-MASKELYNE ON THE was poured into a solution of neutral plumbic acetate a yellow colour immediately developing itself throughout the mass. The whole was then carefully dried powdered and extracted with ether.Wax alcohols dissolve in this liquid in large quantities and mere successive crystallisation will give one of them which seems to be melissin in great purity. The insoluble lead salt can afterwards be decomposed by hydric chloride. In another experiment 12 oz. of the wax were sa,ponified with an alcoholic solution of potash as already mentioned; as soon as the liquid was clear it was precipitated by cold water the alcohol was then distilled 0% and from the mixed soap and alcohols which dissolve in the boiling water the acids were set free by hydric chloride. The mingled mass of acids and alcohols thus formed was then dissolved in boilingalcohol and the acids were saturated with ammonia ; the ammonia soap produced by this means was next thrown down by baric chloride.The alcohol was now distilled off and the precipitate after having been thoroughly extracted with boiling water was thrown on a filter. This precipitate was dried powdered and extracted several times with spirit. The residue was reserved for an examination of the acids contained in it. The part dissolved by alcohol was extracted with ether. Repeated crystallisations from this liquid yield at length a substance melting at first at 87O but ultimately rising to 88'. In this state the substance when fused on a watch-glass exhibits as it cools the concentric undulating rings characteristic of cooled wax alcohols. In appearance it is a very hard semi- transparent electric body exhibiting when in mass but little crystalline structure soluble in hot alcohol and in ether though not in large amount in either of theBe liquids.From its alcoholic dolution it separates on cooling as a gelatinous mass. From ether on the other hand it separates in small foliated crystals. Its analysis produced the following numbers :-I. 0.2858 grm. gave 0.8632 grm. carbonic acid and 0.365 grm. water. 11. 0.2914 grm. gave 0*8824grm. carbonic acid and 0.3738 grm. water. III. 0.2942 grm. gave 0.8898 grm. carbonic acid and 0.3768 grm. water. These results correspond to the following percentages :- CHEXICAL COllIPOSITION OF CANAUBA WAX. Experiment. Theory. I. 11. 111. (C3lHfX0)* Carbon .... 82.37 82.6 82-46 82.30 Hydrogen .. Oxygen ....14.21 - 14.28 - 14.24 - 14-16 3-54 100*00 The alcohol from these numbers was assumed to be melissin. In order to determine its constitutioii with greater exactitude the homologous acid resulting from its oxidation was formed. This was effected in the usual manner the tube containing an intimate mixture of the alcohol and potash-lime was kept by means of an air-bath at a nearly constant temperature of 270° this point being never exceeded. Pure hydrogen was evolved for some hours and when this gas ceased to be developed the substance in the tube was removed and the acids were separated by boiling with hydric chloride. The eliminated acids were dissolved in alcohol and their solution was filtered whilst hot ; when cold the alcohol was re- moved by filtration.The precipitated acid was again dissolved in a very large amount of cold alcohol and then boiled after which this alcoholic solution was converted into an ammonia soap and precipitated with baric chloride. This barium salt was filtered off from the boiling liquid and repeatedly exhausted of any unoxidized wax alcohol it might contain with boiling ether the process being continued till the ether dissolved no further trace of substance. The barium was then removed by boiling the pure salt with hydric chloride. Dissolved in hot alcohol and filtered from the remains of undecomposed barium salt the melissic acid after recrystallisstion presented on being fused and broken a fracture of highly crystalline aspect; and a fkagment fused on a watch-glass gave on cooling the needle-like crystalline radiations which mark the cooling of the wax acids.This substance was found to be in a high degree electrical; it melted at 91" and was only with the greatest difficulty at all soluble in alcohol. Its analysis gave the following results :-I. 0.2981 grm. gave 0.872 grm. carbonic acid and 0.36 grm. water. 11. 0-2972 grm. gave 08666 grm. carbonic acid and 0.3621 grm. water. STORY-MASKEEYNE ON THE 111. 0.2842 grm. gave 0.8286 grm. carbonic acid and 0.3462 grm. water. Them numbers corresponding to a percentage composition of-Experiment. Theory. I. 11. 111. (C31Hfi202). (CYOHfiOOt). Carbon.. . . 79.78 79.51 79.49 79-83 79.65 Hydrogen 13.42 13.53 13-55 13.30 13.27 Oxygen... . -6.87 7*08 I 100*00 100.00 The silver-salt of this acid was now prepared. An alcoholic solution of the acid after saturation with ammonia in slight excess was precipitated by an alcoholic solution of argentic nitrate and the pure white precipitate filtered off and washed in the dark. Dried at looo it presented the appearance of a greyish-white powder devoid of any waxy lustre and veiy readily affected by the light. Its analysis gave the following results :-I. 0.3692 grm. of the salt gave 0,8726 grm. of carbonic acid and 0.357 grm. of water. 11. 0.3276 grm. of the salt yielded 0.0632 grm. of silver. 111. 0.4192 grm. of the salt yielded 0.0816 p.of silver. These numbel-correspond to the following percentage composition:-Experiment.Theory. I. 11. 111. (C30H59Ag02) !C31Hfi1AIS02.) c Carbon .... 64.46 -64.4 64-92 10.75 -10.55 10.65 Hydrogen. Silver.. ... -19-29 19.45 19.32 18.85 . --5.7’3 5-58 Oxygen.. 100~00 100.00 In consequence of the large amount of alcohols yielded by the former process I was convinced that these alcohols were present in the free state. ‘1’0 establish this I endeavoured in a fresh quantity to aepnrate them by direct crystallisation with alcohol my preliminary experiments having proved the wax to be oidy partially soluble in t1ui.t liquid. 400 grainmes treated in this manner after an enormom number and continuation of boillngs which at last barely removed a trace of substance gave- CHEMICAL COMPOSITION OF CANAUBA WAX.91. 126 grarnmes of rsoluble ingredients which melted at 81"; 274 granimes of insoluble ingredients which melted at 86'. The insoluble portion when saponified by potash did not turn of 80 bright a yellow as the whole mass of wax does under the same treatment. This potash solution was then thrown down as before by a solution of lead and the precipitated lead-salt again dried pulverised and exhausted with alcohol. That part of the lead-salt insoluble in spirit corresponded to 85 grammes of acids which were liberated from it by hyclric chloride. From the portion dissolved in alcohol that solveiit was distilled off and the dried mass treated with ether. The boiling ether dis- solved a number of wax alcohols and left a residuary lead-salt which corresponded to 30 grammes of acids.The ethereal solution on cooling deposited mixtures of alcohols from which as before successive crystallisations yielded large amounts of melissin. The soZu62e portion of this fresh quantity weighing 126 gramrnes though repeatedly cryst,allised first from alcohol and afterwards from ether yieldedno products that after fusion on a watch-glass mould give any cq-stalline substance as they cooled. This appeared to be due to a resinous body which though very soluble in these liquids adhered pertinacioiisly to the alcohols as they separated out on cooling. With a view to saponifying and precipitating this substance a minute amount of potash was added to the alcoholic solution which instantly turned very yellow and of a much brighter colour than was observed on subjecting the insoluble ingredients of the wax to like treatment ; plumbic acetate threw down a precipitate com- paratively trifling in quantity; and on boiling it in alcohol it was noticed that the bodies which dissolved in this liquid no longer gave any yellow colour with potash.The resinous body thus eliminated in the form of a lead-salt was too small in amount and too readilF decomposed to invite further enquiry. The mass of substance now dissolved ,in alcohol began after a single crystallisation to exhibit on cooling from fusion on a watch-glass the concentrically annular ridges peculiar to the class of wax alcohols. The ridges were far lem coarse than in the case of cerotin and a few crystallisations from alcohol and ether yielded an individual alcohol of great purity which crystallised at 86O and was in fact melissin.The existence in the free state of a wax alcohol in Canaiiba STORY-MASKELYNEON THE wax to the amount of about one-third of its mass is a fact in vegetable physiology of no little interest. The melissin thus obtained is invariably accompanied by another body in very small relative proportions to it which is deposited in the flasks in fine cryslals; it does not yield annular surfaces on fusion but exhibits a crystalline structure of an entirely different kind. It is a circumstance important to remark that the melissin is present in much larger proportion to the mass of the other alcohols in the part soluble in spirit than it is in the portioii insoluble in this liquid.The whole of the residuary alcohols both from the fi-ee alcohols in the soluble and from the alcohol bases set fiee from the insoluble part of the wax were after the separation of t.he first crystallisations of the melissin mixed and treated together. Dissolved in boiling alcohol and filtered when cold these mixed substances fused at a variable melting point of from 81" to 86O and did not give a clear liquid at any temperature. By several recrystallisations more melissin waa extracted and a body obtained which had a melting point of 87" but which neither solidified in annular concretions nor presented the silky crystals characteristic of melissin. After these had been separated the residues began to melt at 81",and only became clear at tempera- tures over 90".On treating them with benzol there crystallised out a body having a melting-point of 88" which by repeated recrystallisation from this liquid could be raised to 96". After it had been crptallised from ether a few times its melting-point was furt.her raised to 105O and at this stage it solidified with crystalline characters similar to those of cerotic acid but did not saponify with an aqueous solution of potash. The residues of the solvents from which this body melting at 105" had separated yielded at once a substance that melted quite clearly at 84" whence it may be concluded that they con-tained no compound with a higher point of fusion. Substances crystallking between 80" and 84" are separated by the solvents from which this last body was obtained but they are devoid of cryst alliiie structure.Owing to the small amount of these substances obtained from even so large an amount of wax as 400 grammea a much larger quantity of the Caiiauba wax was next worked upon and the reaidues from the various stages of the treatment of these CHEMICAL COMPOSITION OF CANAUBA WAS. 400 grammes were mixed with the corresponding substances furnished by the new mat8eiial. Two pounds of the wax were treated with a mixture of ordinary benzol and alcohol a liquid which not to mention its greater solvent power has its extrac- tive influence enhanced by its higher boiling point. A result of the latter fact is that the wax fuses and is thus more readily acted upon by the solvent.Each portion as before was saponified by an alcoholic solution of potash. The insoluble part was precipitated. by plumbic acetate. By operating on small quantities at a time and allowing the flask to stand until the lead salt had fallen the melissin could be poured off in a state of partial precipitation from the solvent before the latter had become cold; or it may be allowed to cool when the lead salt will be found clotted into a lump at the bottom of the flask thus enabling the overlying portion con- taining the wax alcohols to be mechanically separated with great facility. The lead salt of course is in this way only partially freed from melissin ; it contains however none of the substance which melts at 105O.By again treating the mass thus separated fiom the lead salts with the same solventfi the melissin may be obtained in considerable purity; it still how- ever contains some lead salt. The soluble part was saponified by potash in quantities of about 6 oz. at a time. By filtering the liquid before it had become quite cold the solution of the soap was separat.ed from a quantity of very nearly pure melissin which a few crystallisa- tions rendered colourless and absolutely pure. The soap in the filtrate was precipitated by plumbic acetate and in this way a little more melissin was obtained. It must here be remarked that the mixture of benzol and alcohol used in treating this last quantity of the wax dissolved some of the compounds of melissic and other alcoholic bases with wax acids and that t>here-fore the precipitate produced by plumbic acetate in the soluble part contained a small quantity of lead salts and of acids which properly belong to the insoluble portion.After all the melissin had been crystdlised out as far as could be from both the soluble and the insoluble parts their residues were inixed and treated as one. Solution in alcohol and repeated crystallisatiou added to the amount of melissin obtained. The residuary matter contained in the filtrates from these last quan- tities no longer exhibited annular crystallisation on a watch- STORY-MASKELY~ON THE glass; they consisted in fact of a mixture of the substance melting at 105q with a number of lower wax alcohols whose chemical isolation is a problem for which at present there is perhaps no known satisfiLctory solution.In order to separate the body which melts at 103",these rcsidues were trhen dissolved in a very large quantity of alcohol sufficient in short to retain even when cold the more soluble of the wax alcohols. When cold this liquid was filtered and upon the filter there was left a substance which though it began to melt at 84O did not become transparent till it reached a temperature of 92O. Crystallisa-tion from pure benzol rapidly brought its melting point to 97O and this degree attained no amount of re-cry stallisat ion could raise it above this temperature. With ether however as already mentioned several cry stallisations gave a body having a melting point of 105" which cannot by any means be further raised and this was in fact the Substance previously dewxibed.Although the filtrates from the preparation of this compound yield by a repetition of the process of crystallisa- tion fiom ether a further amount of it this body is present in but very small proportions in Canaiibn wax. Enough however was at last obtained for examination and analysis. It crystal-lises from its ethereal solution in little bosses or lumps radiating fiom a centre. Fused on glass it solidifies with crystalline characters unlike however those of wax alcohols; and it is far less electric than melissin. Its analysis furnished the follow- ing results :-I. 0-271 grm. of the substance gave 0.778 grm.of carbonic acid and 0,3352 grm. of' water. These numbers correspond to the subjoined percentages :-Experiment. Theory. I. '(C39HdL03.) Carbon ........ 78.3 78.30 Hydrogen . . .. 13-73 13.71 Oxygen ........ -7.99 -I 100*00 It is very difficult however to assign a formula to this aiionia- lous substance in the -abHence of more experiments as to its nature. The filtrates from which the above body had crystalliaed CHEMICAL COMPOSITION OF CANAUBA WAX. yielded a series of substances melting respectively at 90" to 9 lo 92* and 95"; these however were obviously miutnres. The alcoholic bodies clissolved by the large amount of alcohol were next treated wit*h a view to a separation of the wax alcohols that they contain.The benzol residues from which the substance melting at 105' had been procured were distilled to remove the benzol and a considerable quantity of the spirit of the alcoholic solution of the lower wax alcohols was likewise driven off; these two residues were then mixed. On cooling a large mms of mixed bodies was deposited which were filtered off. This precipitate of a dark coloiir was then boiled with alcohol and animal char- coal filtered once more whilst hot arid the spirit removed by distillation. By repeatedly crystallising this purified residue from ether several bodies of the nature of wax alcoholp were obtained; they were however necessarily in a state of only approximate isolation. Their melting points were more or less definite being 72" 73" 71j3 78" 80' 81" to 82" 83" and (a little melissin) 85'.There was moreover a small quantity of a substance melting at 84O very similar to one melting at 78'; this however was not melissin aad though cooling from fusion with highly crystalline characters did not exhibit the annular kind of crystallisation. The alcohol melting at 78O appears to be that present in largest quantity and is probably cerotin. The remainder of the above series were present in small but pretty equal quantities. Sufficient of the alcohol which melts at 78O was obtained for the following analysis :-I. 0.2'722 grm. of the substance gave 0.809 grm. of carbonic acid and 0.3428 grm. of water. These results correspond to the following percentage com- positiou.:-Experiment.Theory. I. (C2s&O.) Carbon ........ 81.04 81.17 Hydrogen ...... 13.99 14.12 Oxygen ........ -4.7 1 100*00 It may here be mentioned that every attempt to obtain acids fiom these alcoholic bodies by submitting them to the action of soda-lime proved unsucceasful fkom the fact of the lower acids STORP-MASKELYNE ON THE undergoing decomposition at the temperature necessary for the reaction with the higher ones. In the endeavour to determine with greater exactness the nature of the alcohol the iodide of its radical was formed. In the first instance this body was produced by the action of phosphorus and iodine warmed gradually and subsequently treated by boiling with water and a little sodic carbonate. The resulting substance was dissolved in benzol and crystallised in large granular crystals.A similar preparation boiled with a strong solution of sodic carbonate gave a body with a melting point of 67". Subsequently the alcohol was treated by Von Fridau's method;* it was fused at a tempeyature of 120° to 135' C. in a sulphuric acid bath a small quantity of' phosphorus being dis- solved in it and iodine then added in excess. After being retained for 8ome time at a temperature of 130"C. the mass wa8 washed out with cold water fused and shaken with water at 80' C. It was then dried and digested with ether which left it with a melting point of 67" having dissolved a body that separates from it with a fusing point of 70" to 70O.5. The comportment of the iodide with argentic oxide was then observed.A quantity heated with this oxide and a little water in a sulphuric acid bath to a temperature of looo to 120' C. was converted into a pasty mass which when dried and boiled with alcohol was found to be soluble in this menstruum. Ats the solution cooled an abundant deposit was formed of a body the fusing point of which was found to be 67". Hence it appears that this reagent does not act upon the iodide. Analysis of the iodide produced by the above methods gave the following results :-I. 0.249 gim. of iodide prepared by means of phosphoric iodide when burnt with plumbic chromate in a current of air gave 0.2493 grm. water and 0.5946 of carbonic acid. A residue of urlburnt carbon weighing 0.0015 grm. remained in the platinum boat.11. 0*1009 grm. of the same preparation when heated with lime and sodic carbonate gave 0.0406 grrn. of argentic iodide. The smallness of the quantity employed magnifies the error of analyis. 111. 0.2085 gm.of iodide prepared by Von Fridau's method * Liebig's Handwarterbuch Bd. 11 924. CHEMICAL COMPOSITION OF CANAUBA WAX. gave when burnt 0.2095 gim. of water and 0.4902 grm. of carbonic acid. A residue of unburnt carbon weighing 0.0009 grm. remained in the. platinum boat. These numbers comespoiid with the following percentage composition:-Experiment. Theory. I. 11. HI. (CBOHB1~.) (C3IH63I*) Carbon .. .. 65.722 -64.556 65-693 66.193 Hydrogen.. 11.121 -11-16 11.132 11.209 Iodine .... -21.744 -23-175 22.598 100~000 100.000 The behaviour of the iodide with ammonia and aniline was next examined.When dry ammonia was passed through the fused iodide at 150"to 160"C. it soon became turbid and after the lapse of some time a white granular precipitate was formed in the fused mass. Heated with strong aqueous ammonia in sealed tubes it invariably became opaque and on breaking the points of ther;re tubes under water they immediately filled. The compound resulting from each experiment when boiled with water evolved much ammonia and had then a melting point of 68'05 to 69"C. indicating a return to the state of simple iodide. This body moreover appeared to decompose spon- tan eously. On boiling some of the iodide with aniline and allowing the solution to cool a precipitate formed.This was washed with cold ether in which it is almost insoluble and then boiled in this liquid which dissolved it with great ease and deposited it again in fine crystals. The product when fused evolved aniline leaving a residue with a melting point of 68' to 69O. The preparation of a corresponding chloride of the alcohol radical was next attempted. A quantity of melissin afier repeated treatment with phosphoric pentachloride yielded a compound with a melting point of about 65" which however sank to about 61" afterwarming the body with water. Boiling alcohol extracted from the above product a substance which fused at 64O.5 but after two crystallisations from ether was ob-served to melt at 65" to 65O.5. Two analyses of this substance gave the following results :-I.0.2201 grm. burnt in oxygen gave 002568grm.of water and 0.6035 grm. of carbonic acid. VOL. XXII. I STORY-MASKELYNE ON THE 11. 0.2154 grm. of a specimen once more crystallised from ether gave 0.246 grm. of water and 0.5913 grm. of carbonic acid. These numbers correspond with the following percentage composition:-Experiment. Theory. I. 11. (C3OH6lc1*) ((&1&&1*) Carbon.. 4.0. 74-784 74.865 18.861 79,065 Hydrogen .. 12.962 12.684 13.362 13.390 Chlorine . . . . -7.777 7.545 I 100*000 100*000 These closely agreeing numbers at first suggested that a chlorine replacement had taken place or that a bi-chloride of the biatomic radical had been formed; an inspection of their com- position however renders thig searcely probable.C30H60C12* Ca1H&12. Carbon.. . . . . 73.32 73.66 Hydrogen .. 12.22 12-27 Chlorine .. . . 14.46 1406 100*00 100*00 The body was therefore probably a mixture a view which the change of melting point after treatment with water might be considered to confirm. The acid produced by the action of sulphuric acid on melissin was also prepared and its potash salt submitted to analysis. For this purpose the wax alcohol was heated with sulphuric acid in a water-bath and continually pressed against the sideB of the tube in which the operation was conducted until it became completely dissolved or rather perhaps suspended ; by careful heating merely a trace of discoloration is noticed. If however the temperature of the sulphuric acid be raised too high and the wax be not stirred the liquid soon becomes black and much sulphurous acid is evolved.The wax therefore should never enter into more than incipient fusion. When taken up by the acid it was dissolved in alcohol and saturated witn alcoholic potash which threw down a large white precipitate. Boiled repeatedly with water this precipitate left a large flocculent residue which when mashed free from all sulphuric acid was dried and examined. It was scarcely soluble in alcoholor ether CHEMICAL COMPOSITION OF CANATJBA WAX. and consecutive portions of these solvents removed about an equal amount pointing to a slight solubility of the substance and not an impurity of melissin.The purified body thus obtained fused at 96". An analysis gave the following results :-I. 0.165 grm. when burnt gave 0.1681 grm. of water and 0.3975 grm. of carbonic acid and left in the platinum boat a residue of sulphate of potash which amounted to 0.0249 grm. These numbers correspond with the following percentage compositions:-Theory. Experiment. (C30H61KS04.)(C31HeKS04.) Carbon. ..... 65.69 64-75 65.26 Hydrogen .. 11.27 10.97 11.05 Potassium .. 6-74 7-01 6-84 so,. ....... -17.27 16.85 100.00 100~00 The above analysis like many of the earlier mentioned ones of the alcohol and its acid points to the formula C,,H,,KSO, unless the trifling amount of blackening at its first formation may have caused an increase of carbon and hydrogen in the body.The examination of the acids combined in the Gmaiiba wax -with the alcohol bases remains to be completed. The pertinacity with which a resinous body adheres to these ;acids and refuses to be separated from them by any amount t either of crystallisation fkom solvents or of partial precipita- *tion by any one or by different salts suggested the cautious 'use of a high temperature. By gradually raising the tern- ]peratare to about 240" in an air-bath the resinous sub-r3tance was successfully grappled with and acids obtained by czrystallisation fiom alcohol and ether which on fusion and c;ooling came to present the characteristic features of wax acids (3n a watch-glass. Acids with melting points &om 90O-5 and 13Oo-78O to 40°,were thus obtained but their further isolation 1md examination remains to be worked out.* * The greater part of the investigation of which this memoir is an account was carried out by the author in the years 1855-7; other duties then interfered and lime since prevented its completion.It is published nowJbecause no one having t'aken up the subject exhaustively in the interval the author trusts the interetit a,ttached to the composition of Canauba wax may induce some other chemist to c omplete its chemicd history. 12

ISSN:0368-1769    

DOI:10.1039/JS8692200087

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

100 VIII.-On the Chemistry of Sugar Rejning. Discourse delivered before the Fellows of the Chemical Society February 4, 1869.1 By DR. WALLACE, F.R.S.E. Glasgow. THEscience of chemistry embraces 80 wide a range of subjects that there are few men who possess sufficient versatility of mind or endurance of body to undertake the study of every one of its numerous departments. Hence we find that while all chemists regard original research as the highest aim of the profession there are many who have rendered good service to the science as literary chemists teachers of chemistry analyti- cal chemists assayers metallurgists and manufacturers. The Chemical Society has necessarily and very properly been chiefly occupied iu the promotion of original work but it has occa-sionally given some countenance to the scientific study of certain manufacturing operations and I think I may say that the publication in the Journal of the papers or discourses on such subjects as the manufacture of glass by Mr.Chance and the application of certain forms of furnace to the making of iron aid steel by Mr. Siemens has given great satisfaction to a large section of the Fellows of the Society especially those who are non-resident a large proportion of whom are interested in technical chemistry. In this country unlike Germany and France chemical technology receives no official acknowledg- ment from the State nor fkom the universities and the thanks of those interested in that important branch of the scienee are due to this Societ'y for the eiicouragement it offers to the pro- secution of study and research in technical subjects.While therefore I feel grateful to the Council of the Society for afford- ing rrie the honour of delivering a discourse here this evening I feel that I need offer no apology for bringing before them a subject of high utility and one which possesses many points of interest to the scientific chemist. The considerations which have induced me to bring before you the chemistry of sugar refining are these:-First the industry is one of very great importance ;secondly the trade has for some years been affected seriously by foreign competition; and thirdly the refineries in London formerly the principal seat WALLACE ON THE CHEMISTRY OF SUGAR REFINING.101 of refining in this country have for some time suffered from a very great depression in some cases almost threatening annihilation. As regards the extent of the industry in this country a few statistics will suffice According to the Board of Trade returns for 1868 the importation of sugar of all sorts amounted to 594,656 tons or in round numbers 600,000 tons. This is charged at various rates of duty but if we take 9s. per cwt. as the average the total revenue to the State from the import of tmgar will amount to nearly 53 millions and the total money value of the sugar including duty to about &21,000,000. I am not able to state what proportion of the quantity I have mentioned enters into direct consumption and how much is refined but I think I am safe in saying that at least 400,000 tons per annum are refined in this country.The competition of foreign countries particularly France is entirely in loaf sugar the quaatity of which imported in 1868 was 34,039 tons while the previous year it amounted to 42,047 tons. This is an alarming fact and one that de- serves the earnest attention both of our refiners and of our legislators. Either our refiners are f'iar behind in the march of improvement in manufacturing processes or the French refiners possess an unfair advantage in the fihape of drawback on duty which is equivalent to a premium offered by the French Govern- ment to the exporter of loaf sugar. That the latter is the fact I have attempted to show in a discourse recently published and I will not occupy our time with a repetition of it.If our refiners are really backward in adopting means to keep up with the times they deserve to succumb to the superior knowledge and skill of their continental neighbours ; but if the other ex- planation of the enormous importation of loaf-sugar is the true one then our Government ought to take stepa to have the cause removed and our own countrymen put on terms of equality with the French refiners. Besides the drawback on duty to which I have referred the French have a protective duty on foreign refined sugar which makes it impossible for our refiners under any circumstances to export refined sugar to France. Then as to the depression of the trade iii London I think it depends upon a number of circumstances but mainly upon the extraordinary development of the industry within the last few 102 WALLACE ON THE CHEMISTRY OF SUGAR REFINING.years in Greenock and Glasgow. In 1857 the quantity of sugw refined in the Clyde was 38,336 tons while in 1867 it rose to 178,013 tons or considerably more than four times the amount. Last year the quantity refined was rather less being only 171,643 .tons but even this ie fully two-fifths of all the sugar refined in the United Kingdom. At present there are twelve refineries working in the Clyde viz. ten in Greenock and two in Glasgow besides three standing idle or building and besides these there was refined last year about 11,000 tons by one house in Leith. Now there are in London twmtyrefineries in Liverpool eleven in Bristol four or five in Plymouth two in Manchester two in Newcastle-under-Lyme one and in Dublin one; but of those in the metropolis a considerable number are doing nothing.It appears to me that the London refiners generally have been somewhat tardy in adopting the most recent improvements introduced in the provincial refinei<eR and they have been unwilling to give up the making of loaf-sugar which has not lately been profitable for the reason I have named; and besides they work under the disadvantages of dear labour and water not particularly well suited for the purpose; and above all they are prevented from reburning their own charcoal and have to send it out to people who make a distinct trade of it.Thus while in Greenock it costs 3s. 6d. to reburn a ton of charcoal the same costs in London fi-om 228. 6d. to 25s. thus inducing the refiner to use less charcoal than he would otherwise be likely to do. The description I shall give of the process of refining mill refer to crushed or soft sugar and chiefly to the Greenock system the principal peculiarity of which is that no syrup is produced; all the sugar leaves the refinery as it came to it in the solid form and the loss consisting of insoluble matter compounds vege- table and mineral abstracted by the charcoal and loss in working do not amount in all to more than 5 per cent. Whether this system is theoretically a correct one I am not prepared to say but at all events it has been commercially successful; and the precision and rapidity with which the work is done appear to me to place rrugar refining at the summit of perfection as a manufacturing process and one which might with great ad- vantage be imitated in many branches of technical chemistry.WALLACE ON THE CHEMISTRY OF SUGAR REFINING. 103 sugar Refining. In refining raw sugar it is very important to make a proper selection of the raw material. The qualities are very various and each kind is adapted for a particular system of refining. In the Greenock system for example in which no syrup whatever is turned out it is absolutely essential to use sugars containing only a moderate amount of uncrystallisable sugar say not exceeding on the average 3 or 4 per cent.; but where a consider- able quantity of syrup is produced the quality of sugar is of less importance and concrete and low sugar such as spup Mauritius Jaggary and Manilla may be used. Mixtures are often judicious such as beet sugar with sorts which contain much fiuit sugar but in the Greenock system a large proportion of beet must be avoided as the soluble salts accumulate in the lowest kind of the refined product and communicate an objectionable taste besides retarding crystallisation. In pur- chasing sugars for refining several points demand attention. The absolute quantity of cane sugar is important as determining mainly the proportion of refined capable of being produced; and the fruit sugar and salts as preventing to a large extent the crystallisation of the cane sugar demand attentive considera- tion.The extractive matter determines chiefly the amount of animal charcoal required as well as the amount of deterioration of the charcoal. The insoluble matter when excessive is trouble-some to wash and some kinds of insoluble matter are dificult to filter stopping up the pores of the cloth which the her particles pass through and are afterwards deposited in the char- coal to its great detriment This irJ particularly the case with Home kinds of East Indian sugar. The analysis of sugar is very simple to those who have some practice in this kind of work and most of our refiners pay great attention to this branch of their business. Many of them have qualified chemists in their refineries while some employ a pro- ferssional analyst.I have myself made aboiit 400 analyses of raw sugar chiefly for refiners in Greenock and the following table contains a few results of analyses of some of the varieties of raw sugar used by refiners :- 104 WALLACE ON TffE CHEMISTRY OF SUGAR REFINING. O& d -------_. ---~ Cane eugar .. 92.35 92-31 90.41 90.80 89.00 84.20 67.00 47.0 88 -31 Fruit sngar .. 3-38 4.06 3.84 4.11 5.85 8-45 11 -36 20.4 4 -82 Extractive &c. -66 '66 '95 -77 *76 1*70 1'93 2.7 a94 Soluble salts.. -62 *37 *86 *92 *62 1 *I0 -76 2'6 -80 'Insoluble .. .. -15 *04 '22 '20 *06 -15 -73 Water .. . . .. 2-84 2.56 3'72 3.20 8.72 4'*55 18-80 2y.3 4 -40 ,----___ 100.00 100'00 100*00100~00 100 -00 1 1 1 1 ;; 1 1 CoIour,D.S.] 13 13 10 10 .. 8 Cane sugar 12-obtainable 85.9 8614 82.3 82-1 7Q-2 51..*8 13.6 79 -6 -These analyses muet not be coneidered as typical of the various kinds of sugar for all of them vary exceedingly; but they give a fair idea of the description of sugars used in refineries where crushed sugar is made. Several of the lower sorts are unfit for refining on the Greenock sygtem. The French mode of determining the value of raw sugar is upon the whole a very fair one and is based upon two assump- tiom namely lst that each perceatage of fruit or uncrystal-lisable sugar prevents the crystallisation of an equal amount of cane sugar ; and 2nd that each part of soluble salt prevents the crystallisation of five times its weight of cane sugar.My own experiments bear out the general accuracy of these assump- tions. To value a sugar or find the amount of extractable cane sugar in it we take the total amount of cane sugar as deter-mined by chemical analysis or the polariscope and deduct from it the fruit sugar and five times the soluble salts and the remainder is the quantity required. Thus take as an example a sample of Paraiba sugar containing 84.9 cane sugar 6 of fruit sugar and 1.2 of soluble salts the obtainable cane augar from this variety would be 72.9 per cent First Operation. 8olutioK The first operation in sugar refining is dissolving or what is technically called LL blowing-up,'' from the circumstance that WALLACE ON THE CHEMISTRY OF SUGAR REFINING.105 ai 5 c-.l B 4 84 -90 86 *80 86 00 87.06 86.73 79.00 74.60 76.53 72.60 94.30 87-80 6 -00 5 '03 6.35 6.95 6 05 11.76 16.13 13 38 13.95 -25 -33 1 .28 1 ,72 1 *62 *65 1 .29 1 .32 1 -70 54.47 2.11 -27 95 1 -20 1 *21 1 -44 -68 -88 1-95 1 .61 1-86 1 35 1.30 5.92 1 *lo 2 -01 -63 -54 5 -52 3 .04 5 -34 5 -52 100 900 100 .oo 100 a00 100 -00 I ~ 6 6 76.3 57.5 open steam was formerly used in the process producing a violent agitation and blowing noise. Although I do not purpose to detail the mechanical arrangements of the sugar refinery yet I must mention briefly some particulars in order that the chemistry of the subject may be understood. The different floors of a sugar house generally six or seven are arranged so that in the process the sugar passes down fiom one to the other.Acting upon this principle the sugar is hoisted to the top story or garret where it is removed from the hogsheads boxes baskets or bags in which it is imported and shovelled through holes in the floor into the blow-ups which are situated on the floor below. These vessels are cast-iron pans about 4 or 5 feet high acrid from 6 to 10 feet in diameter. At some distance fiom the bottom leaving room below for a series of steam pipes is a false bottom perforated with holes upon which the sugar rests until it is dissolved and both above and below this shelf revolving arms are moved by machinery so as to keep the liquor in constant motion. The operation is commenced by placing in the pan a sufficient quantity of water or thin liquor turning on the steam to the heating-worm and then filling in the sugar as quickly as it can be knocked out of the casks.If the blow-up is well constructed the filling should be completed in half an hour when the gravity of the liquor should be about 28' Baumd (or 1-225sp. gr.) and the temperature as nearly as possible 180° F. The liquor consists of about two parts raw 106 WALLAUE ON THE CHEMISTRY OF SUGAR REFINING. augar to one of water and a pan of 10 feet diameter will dis-solve at each filling about seven or eight tons of raw sugar. During the heating a scum iises to the surface which is skimmed with nearly flat perforated ladles but the amount of flocculent and insoluble matter so collected is very trifling.Such is the simple process as conducted in most of the Clyde refineries but elsewhere the liquor undergoes in the blow-up various kinds of treatment with the object either of removing a part of the colouringmatter of neutralising the trace of acidity in the sugar or of facilitating the subsequent process of filtra-tion so as t.0 produce a perfectly clear bright liquor. It is a very common practice to add a sufficient quantity of milk of lime or sucrate of calcium in such quantity as to neutralize the acidity of the sugar and although this is not done in some of the best conducted refineries yet I consider it a useful addition provided too much lime is not used for if excess is employed it tends to deepen the colour of the liquor and to give the char- coal additional work.Again blood was formerly much used for clarifying as it coagulates by heat producing flocculae which enclose and carry down fine particles of mud or other insoluble matter. The coagulated albumin also abstracts a small propor- tion of the colouring matter for which it has a strong attraction. Instead of blood the solid albumin obtained by evaporating the white of eggs or the serum of blood at a low tempemture has been used and has the advantage of not being quite so filthy as blood; but all these bodies which make the syrups very impure are now generally dispensed with. Various other sub- stances have been used instead of blood such as a mixture of sulphate of alumina and lime which forms a gelatinous precipi- tate of alumina but is objectionable on account of introducing calcic sulphate soluble tricalcic phosphate and soluble phosphate of alumina and lime.The greatest objection to these mixtures is the danger of the common workmen who are necessarily entrusted with the application of them using excem of one or other and so ma.king the liquor acid or alkaline and thus doing more harm than good. Above al1,it does not appear to be absolutely necessary to add anything to the liquor and many of the first refiners use no chemical agent whatever. For the removal or partial removal of the colour of the sugar ths dust of animal charcoal is sometimes introduced and if it is quite new that is not used in sugarrefining previously it has a good WALLACE ON THE CHEMISTRY OF SUGAR REF"& 107 effect.The charcoal can only be used once however as it gete mixed up with the insoluble matter of the sugar. The next operation is a purely mechanical one and consists in passiiig the solution of sugar through twilled cotlton filter bags of about two feet diameter crushed into coarse canvas sheaths of about 6 inches in diameter. These bags are 6 or 8 feet long and are fastened to the number of 200 or so to the bottom of a shallow tank into which the liquor is run from the blow-up pans and they are surrounded by the sides of an iron box so that the liquor is kept hot and also that steam may be introduced to keep up the temperature. Decolorising of the Syrup. The next operation after having obtained the saccharine solution clear anti bright is to remove the cofouring matter and this is effected by bringing it in contact with animal charcoal otherwise called bone black.This variety of charcoal has been found by practical experience to be the most suitable for sugar refining. Many kinds have been tried some of them as decolori- sing agents much more energetic than bone-black but none of them have been found to possess that peculiar combinatioii of qualities which is required-freedom &om soluble salts and from considerable quantities of calcic sulphate or carbonate sufficient density to sink readily inthe heaviest sugar-liquor and at the same time great porosity ;together with such a degree of hardncss that it will not suffer sensible deterioration by being ahovelled about and reburned every fourth day for several years.These qualifications exist in no kind of charcoal in such a marked degree as in that from bones. An artificial mixture of clay and some form of carbon has indeed been made which is said to rival animal charcoal but as I have heard nothing of it lately I fear that it has not been found so ad-varitageous as was expected. The only kind of charcoal I have found at all to approach that from bone is the kind made from certain kin& of sea-weed but even this variety is wanting in some of the characters necessary for refining sugar. Other decolorizing agents than charcoal have also been proposed. Sulphurous acid has been tried repeatedly and pro- cesses are published eveiy two or three years in which ite use is adyocated each writer apparently ignorant of the fact 108 WALLACE ON THE CHEMISTRY OF SUCIAR REFINING.that his results are already well known. St best it only removes about three-fourths of the colouring matter and the liquor requires to be treated with charcoal just as much as if sulphurous acid had not been used. It is true that sulphurous acid does not alter cane sugar like most other acids but it i8 very liable to change into sulphuric acid; and although this may be neutralized with lime still the calcic sulphate is very injurious to the charcoal which must afterwards be used. With regard to the bleaching action of ozoue I have made no experiments myself but I understand that its application has not as yet been practically successful and even if it were found economical in bleaching the colour still it would not enable us to dispense altogether with charcoal and I fear its oxidizing action would be likely to prove troublesome.Upon this point however I am not qualified to give an opinion as I have not had an opportunity of seeing the process in operation. The carbonatation process as applied in the continental factories where sugar is made from the juice of the beet and which is attended with excellent results has not so far as I know been applied on the large scale to the process of refining raw cane-sugar and I do not think its application would be advantageous. The sugar solution for this process requires to be rather dilute and consequently would require to be boiled down before passing through the charcoal for it would not be a substitute for charcoal but only an adjunct to it.I have made careful trials of the process with dark sugar and have found little or no benefit from it as regards colour although it makes the liquor beautifully clear and bright. I think how-ever that in certain cases it might be applied with good results as for instance in purifying the washings of animal charcoal which are very impure and very troublesome to deal with and also to bag filter washings and any other impure products of the process of refining To those who are not acquainted with the carbonatation process I may describe it very briefly. The sugar dissolved in a sufficient quantity ofwater is mixed with milk of lime the quantity depending upon the colour of the sugar to be treated and after being brought up to a moderate heat carbonic gas is passed through the liquor until the lime is completely carbonated after which it is boiled to decompose the calcic bicarbonate ;and the precipitate then becomes grainy and settles readily.In the beet fa-ctories the process is repeated WALLACE ON THE CHEMISTRY OF SUGAR REFINING. 109 with a smaller quantity of lime after which the juice is boiled down to 20° or 23O B. and passed througb charcoal. Impure saccharine products such as bag filter and char washings and low syrups much contaminated with salts may also be purified by precipitating the sugar as a sucrate of calcium or barium and afterwards separating the base by car- bonic gas or in the case of baryta by sulphurous gas.I consider it an excellent arrangement to have connected with every large refinery a smaller one immediately adjoining it where all im-pure products are separately treated and worked up separately from the sugars made in the refinery proper. As a preparation for the decolorizing process it has been proposed to wash or digest the raw sugar with alcohol before dissolving in water and this idea has been tried on the large scale in Belgium but has been discontinued. Theoretically the treatment of raw sugar with alcohol appears to be highly ad- vantageous. The quantity of cane sugar in a pure form obtain- able fiom raw sugar is very much reduced by the presence of soluble salts and fruit-sugar the former preventing the crystal- lisation of five times its weight and the latter of an equal weight of cane sugar.By the use of alcohol together with a minute quantity of hydrochloric or acetic acid to act upon the calcic salts present the whole of the impurities with the ex- ception of some of the colouring matter may be removed and nearly pure cane sugar obtained. But in practice there are serious difficulties to be overcome. A very pure and nearly absolute alcohol milst be used andthe expense of maintaining this would be considerable and the inflammable nature of the spirit is a serious objection; but under any circumstances it would be quite out of the question unless the spirit were obtained free of duty.A moderate sized sugar-house would require something like 10,000 gallons of spirit to start with and the duty on this alone would be about as many pounds sterling and as this quantity would require to be re-distilled every day there would be a considerable and unavoidable loss. The process has long been used for testing raw sugar and most successfiilly but the possibility of its successful application on the large scale has yet to be demonstrated. Filtration tlwouglz. Chawoal. After this rather lengthy digression we retuim to the process of sugar refining as it wtually exists. After being made clear 110 WALLACE ON THE CHEMISTRY OF SUGAR R;EFININU. and tranrrparent by passing through the bag filters the liquor is in into iron tanks or cisterns filled with animal charcoal where it is allowed to settle for several hours after which it is slowly drawn off below while more of the dark coloured liquor is run on to the top so asto keep the cistern full.As this goes on the liquor which comee away at first perfectly colourless becomes after a time distinctly yellow and the sugar solution is replaced by the syrup from a previous refine; and lastly this is washed out with hot water until no appreciable trace of sugar can be found in the washings; then the charcoal is further washed with a copious volume of boiling water next with some cold water and afterwards drained removed from the cisterns and taken to the kilns to be reburned. Such in few words is the decolorizing process which however I must now describe in greater detail.The cisterns are of various fbrms and sizes; some are square and shallow some of great depth 40to 60 feet and so on; but the kind universally employed in the Clyde refheries are circular and of no great depth being generally about 9 feet diameter and 16 feet deep and capable of containing from 20to 25 tons of charcoal according to its density. The cisterns are covered on the top and are constructed to bear the pres- Sure of a considerable column of water or liquor which may be applied when necessary to cause a more rapid filtration. The quantity of charcoal to a given weight of sugar varies exceedingly. Where water is scarce or dear coals dear and above all where the charcoal has to be sent out of town to be reburned the quantity of char is necessarily reduced as far as possible but in other circumstances the proportion should not be less than 25 cwt.of char to a ton of sugar. The size or “grist” of the charcoal must depend to some extent on the shape and size of the cisterns; but in all cases where it is possible to use it a small size such as would pass through a sieve of 20 meshes to the inch but would be retained by one of 30 meshes should be chosen. Theoretically the smaller the gist the better the finest dust being the best of all but prac- tically the char must have a sufficient size to permit the liquor to pass through it in a reasonable time. Then as to the quality of the charcoal it would occupy an entire lecture to go fully into that department.The whole subject is fully dis- cussed in a lecture which I delivered last year in Glasgow WALLACE ON THE CHEMISTRY OF SUGAR REFINING. 111 and which will be found in the Proceedings of the Philosophical Society of Glasgow (vol. VI. part 4) also in abstract in the “Chemical News.” On the present occasion I can only refer to some points connected with this most important subject. Animal charcoal when new consists of carbon calcic phosphate and carbonate and minute quantities of some other substances ; the composition is a little variable but the following results of analysis of three varieties will convey a good idea of its usual constituents A being made from ordinary bones col- lected in this country; B from South American shank bones and C from what are called camp bones which are frequently buried for some years before they are collected.Dry. Carbon nitrogenous.. A. 9.71 B. 7-64 C. 10.37 Calcic phosphate &c.. 80.48 84.05 78.70 Calcic carbonate. . .... 8.82 7-61 8.05 Alkaline salts. .. . .. -Calcic sulphate ..,.. . *34 *30 *20 -25 *53 -58 Feii-ic oxide -12 Silicious matters . . . -23 ... ..... -15 *lo -21 1.56 100~00 100~00 100~00 Cubic feet per ton (dry) 51 49 47 The above analyses represent the charcoal as being dry in order that they may be compared with one another but prac- tically the article is always sold with about 10 per cent. of water. The so-called carbon in animal charcoal is not by any means pure for it contains a very notable amount of nitrogen and a small proportion of hydrogen the quantities of both of these elements depending upon the degree of heat to which the charcoal has been exposed in the process of manufacture.Generally the quantity of nitrogen is about one-tenth part of the total carbonaceous matter but sometimes I have found it considerably more. The proportion of hydrogen in well-burnt animal charcoal is exceedingly minute being in one particular case (new) only 0034 per cent. Old charcoal which has been frequently used in refining and reburned contains less nitrogen and the proportion appears continually to decrease. I have 112 WALLACE ON THE CHEMISTRY OF SUGAR REFINING. found it as low as .3 per cent. and as the charcoal which gave this amount was not excessively old I have no doubt it may be reduced even further.I believe that the nitrogen is an important and essential constituent of animal charcoal and it is certain that no description of charcoal which does not contain an appreciable quantity of nitrogen is a good decolorizing agent. Wood charcoal for instance although eminently porous and an excellent absorbent of gases is a very poor decolorizing agent and is practically useless. Red-hot animal charcoal quenched with water evolves ammonia and I believe that the practice of cooling charcoal in this way pursued by some refiners is a highly injurious one. New charcoal always contains traces of ammonia but the amount is extremely minute being in a particular case only -011per cent.The effect of this minute quantity and of traces of sulphide of ammonium is readily seen in the sugar iun over new charcoal which should never be used until after it has been well washed and reburned. New charcoal also contains invariably a minute quantity of sulphide of calcium and gives off the odour of ‘hydric sulphide when treated with an acid and even when moistened with water. In a particular case a sample of new charcoal gave -08 per cent. of hyclric sulphide when treated with an acid. Charcoal both new and old retains appreciable quanl ities of gases which escape when cisterns containing it are filled with liquor and these gases frequently expIode when a light is brought near the top of the cistern. In a sugar-house the charcoal is usually burned every fourth or fifth day and is thus reburned from seventy to ninety times in a year.Old charcoal has not the same chemical compofiition as new. The carbon almost invariably increases and if the kilns are perfectly tight ought to increase so that the pores are gradually filled up with the deposit of carbon arising from the carbonizing of the vegetable matter extracted from the raw sugar which it has been employed to purify. This deposit of carbon is a very great evil in sugar refining and should be pre- vented as far as possible by washing the charcoal with boiling water before reburning. In some refinerieR the proportion of carbon does not increase and in others it speedily diminishes so that it sometimes does not exceed 2 or 3 per cent.When this decrease takes place it arises either from the admis- WALLACE ON THE CHESIISTRY OF SUGAR REFINING. 113 &on of air to the charcoal while hot or from excessive burning which causes a reaction to take place between the carbon and the elements of water resulting in the formation of carbonic gas and marsh gas. But if the kilns and cooling boxes are tight and the heat not excessive the carbon will inevitably increase rapidly unless we ta-ke the precaution of washing out of the charcoal before reburning nearly all the organic matters absorbed from the sugar liq-uor. Extensive washing has also a most beneficial influence in rernovi'ng mineral salts absorbed from the raw sugar. In all raw sugars a certain proportion of mineral salts is found varying in ordinary cane sugam from 4to 1per cent.in syrup sugars from 1to 2 per cent. and in beet sugays such as are used by the British refiners from 1+ to 7 per cent. The highly soluble saltg such as those of potassium have no effect upon the char- coal and only annoy the refiner by accumulating in the syrups ; but calcic sulphate a salt only slightly soluble in water is readily absorbed by charcoal and can only be removed by extensive washing. It is rather a sinplar fact that so long as the sugar liquor is strong the sulphate is absorbed and retained; but whenever the washing begins it comes away in the wash- ings so that it is no uncommon thing in boiling down weak char washings to obtain a plentiful crop not of sugar but of gypsum.When the water is hard and contains much calcic mlphate the proper washing of charcoal becomes almost if not quite an impossibility; and I have myself examined char- coal which contained 2+ per cent. of that compound. In beet factories where lime is freely used in clarifying the juice the pores of the charcoal soon become choked with calcic carbonate rendering it useless unless the compound is removed by treat- ment with an acid. But charcoal becomes old and useless from another cause ; it gradually shrinks in volume and the pores must become either lessened or altogether obliterated. The space occupied by a ton of new charcoal when dry is usually about 50 cubic feet but after being a few months in use it is reduced to 40;and so it goes on ghrinking until it reaches 28 cubic feet which is the densest charcoal out of about 400 samples that I have tested.Now this does not arise from an actual increase in the density of the charcoal. Ihave tried the specific gravity of old and new charcoal and have found the difference very slight indeed. Thus VOL. XXII. K 114 WA4LLACE ON THE CHEMISTRY OF SUGAR REFINING. new charcoal occiipy-ing50.6 cubic feet per ton had a gravity of 2.822 while t'he old occupying only 35 cubic feet had a gravity of 2.857. The fact is that the heat to which the char is subjected produces a semi-fixion of the calcic phosphate which is its most abundant constituent and causes a shrinking in the bulk of the particles. The following siniple experiment serves to illustrate this point.A quantit'y of new charcoal measuring 48 cubic feet per ton was exposed in a covered crucible to a rather strong heat for an hour after which it had contracted to 43.2 cubic feet ; after two hours more to 40.8 cubic feet ; after other four hours it measured 38 and with still four hours longer of a strong heat 35.5 cubic feet; thus losing in eleven hours as much of its porousness as it woiilcl by being worked in a sugar house for two years. It is well known to chemists that oalcic phoaphate is fusible at a high heat but the temperature of a charcoal kiln is sufficient to produce only agglutination. New charcoal burnt white has the appearance of bits of chalk but old char- coal has the texture of porcelain or flint.The quantity of liquid capable of being retained by the two kinds is also remark- able. If a funnel is filled with good new charcoal perfectly dry and water poured on it as long as it is retained it will be found to hold in its poreq from 80 to 100 per cent. while old charcoal retains from 30 to 45 per cent. according to its quality. Again dry new charcoal does not become perceptibly wet unless at least 20 per cent. of water is added to it while old charcoal is made wet with 5 per cent. All these considerations point to the necessity of renewing the charcoal very frequently in order that it may act efficiently. It is not enough merely to replace the dust that is sifted out occasionally and to make up by the addition of new char for the shrinkage in volume that is constantly taking place.If proper work is to be done and the charcoal maintained in a state of real efficiency a portion of the entire char (not the dust only) should be set aside from time to time and replaced by new material at the rate of 50 per cent. per annum and the addition should be made constantly; one two or three bags of new charcoal in every cistern according to its capacity. As regards the proper quantity of charcoal to use per ton of augar that depends a good deal upon the kind of sugar used and upon the quality of the charcoal; but the smaller the quantity of charcoal the better for the use of a large quantity WALLACE ON TEE CHEBIISTRY OF SUGAR REFINING. 115 entails a loss of sugar and the production of an extra propor- tion of weak and impure washings.For a ton of sugar 25 cwt. of charcoal is amply sufficient if the quality is good and if fine sugars are used an equal weight is enough. It is a mistake to suppose that a large quantity of bad or exhausted charcoal will serve the same purpose as a moderate amount of good charcoal. Not only does it occupy more space and SO limit the production of refined sugar but it does not in any quantity do the work so well besides producing an overwhelming amount of ‘6 sweet water,” or charcoal washings. I have found that it is impossible on a practical scale to wash out all the sugar from charcoal so as to make the washings worth boiling down and that for every 100 parts of charcoal there is it loss of *75 of sugar.If therefore an equal weight of charcoal is used the loss of sugar will be -75 per cent. while if two tons of charcoal are used for each ton of sugar the loss will be 16 per cent. from this source alone. I have selected a few analyses of specimens of old or used charcoal which will coiivey an idea of the variety to be found in different sugar-houses throughout the country. D. E. F. cf. H.I. K.L.M. Carbon nitrogenow 9 74 10.60 12.86 19.64 7.42 10 63 5.82 17 28 2 56 Calcic phosphate .. 82 8u 83 20 81-80 73.20 87-08 80 56 77.26 792~90.73 Calcic carbonate ,. 5.92 4.15 2 92 3.18 1-92 4.52 14.66 1.06 3.50 Calcic sulphate.. .. *67 -64 -42 1.12 .95 2 24 1 03 -59 1 10 Ferric oxide . . ,. ,. *33 -55 .67 66 -85 *72 *21 -69 1-17 Silicious mattera .. *54 -86 1 .33 2.20 1 .’i8 1.32 1.02 -83 -94 100 00 LOO *00100 ,oo 100so0 100 .oo 100 .oo 100 -00100-00100-00 Cubic feet per ton. . D is first-class charcoal; E is of excellent quality; F is of fair average quality; G is pretty old and very much glazed; H is very old and overburned; I has been used in a sugar-house where hard water is employed; K has hen used in a con-tinental beet factory; L has been soured in the process of washing; and M has been exposed to the air while cooling. The power which charcoal is capable of exerting in removing colouring matter from solutions is truly astoniahing. A very good lecture-room experiment consistrj in pouring into a funnel 116 WALLACE Oh' THE CHEMISTRY OF SUGAR REFINING.filled with good animal charcoal an aqueous solution of cochi- neal vhen it comes through perfect,ly colourless and its presence in the charcoal in an unaltered form may be illustrated by boiling the charcoal with alcohol when it gives up the colouring matter to that liquid. Port wine may be used for the same purpose and with a like result,. Charcoal has also the power of absorbing vegetable albumin gum oxide of iron calcic carbonate and hydrate and calcic sulphate. In sugar we have vegetable albumin extractive matters and invariably some salt of calcium and all these as well as the colouring matter are removed by the charcoal ; and not only so but their removal is important and essential so that if we could practically bleach sugar by ozone chlorine sulphurous gas or any other chernical agent we should still require to use charcoal to purify the sugar.The active ingredieiit in animal charcoal is unquestionably the iiit.rogenous carbon for if the charcoal is burned perfectly white not only on the outside of the grains but to the very centre of each particle it no longer retains the slightest trace of decolorizing power. But it is quite evident that the carbon owes its extraordinary powers to its extreme porosity the carbon being infinitely cornminut'ed and kept asunder by admixture with ten times its weight of calcic phosphate. The dark-brown solution of raw sugar comes away at first perfectly colourless; after a time the pores of the charcoal begin to get saturated and the liquor gradually becomes yellow and even brown if the process is continued long enough.The sugar refiner takea care to economize hi8 charcoal by passing through it first a fine quality of raw sugar afterwards an infeiior sort and lastly syrups from the drainage of previous refines. The calcic carbonate in charcoal is very useful in neutralizing the minute quantity of acid present in almost all raw sugars and also the acids always formed during the washing of the charcoal by a process of fermentation which it is very difficult to prevent. Charcoal deprived of all or nearly all its calcic carbonate is very objectionable and is sure to give rise to sour liquors and the occurrelice of iron in the syrups When the water used for dissolving the sugar and for washing the charcoal is very soft the calcic carbonate gradually decreases until in pretty old char it is reduced to 1Q per cent.and even in extreme cases disappears entirely. On the other hand when very hard water is uaed the calcic carbonate either decremerr WALLACE ON THE CHEMISTRY OF SUGAR REFIXING. 117 very slightly or it increases and sometimes to an alarming extent; and in beet factories on the continent wliere lime is freely added to the juice the eril is a very serious one. In this case it closes up the pores and many expedients have been adopted for the purpose of getting rid of it. This is done; either by washing with I or 2 per cent. of hydrochloric acid diluted with a sufficient quantity of water to saturate the char or better by Mr.Beanes’ process which consists in impreg- nating the burnt charcoal with perfectly dry hydrochloric gas until it is saturated then exposing it to the air until the excess of the gas escapes and lady washing with water and burn- ing. In beet factories and in some particular circumstances in refineries also when the liquors are slightly alkaline the process is attended with the best results but I have always objected to the use of acid in refineries using soft water for there the calcic carbonate instead of being in excess is barely sufficient to neutralize the minute quantity of acid in the raw sugar. That animal charcoal treated with an acid gives a whiter liquor than it would otherwise do is easily demonstrated ; but on the other hand it appears from my own experiments and those of others that it is impossible to get rid by mere wash- ing of every trace of acid; and the consequence to be feared is that the sugzr in the liquor will be to some extent converted into fruit sugar during the process of boiling down that the char washiugs will be very soar and the syrups contaminated with iron.In other words I believe that in a refinery working under ordinary circumstances less syrup is produced than would obtain if the charcoal were treated with hydrochloric acid while in the latter case the colour of the sugar produced would be superior. It may be interesting to mention that while dry hydrochloric gas passed over dry calcic carbonate does not give rise to any action whatever the dry gas passed over absolutely dry charcoal containing calcic carbonate de- termines the complete decomposition of the latter especially if.the charcoal is warm. Bean es’ process and others of a similar nature may be applied with advantage to new charcoal for the purpose of bringing it at once into efficient working condition. New charcoal contains traces of ammonia and sulphide of ammoniuni and also some fkee lime besides an excessive quantity of calcic carbonate; and although the ammonia is removed and the free lime carbonated by the processes of washing and KfL 118 WALLACE ON THE CHEMISTRY OF SUGAR REFINING. re-burning to which it ought always to be subjected before being employed in sugar refining yet the excess of calcic carbonate makes the liquors very yellow and it is usually five or six weeks before the charcoal is in first-rate condition.When however the new charcoal is added in small proportion to the old there is no danger of any harm resulting but on the contrary an immediate advantage is observed. The oxidizing power of charcoal is well known to chemists and although this property is useful in purifying water and in deodorising yet in sugar refheries it is the cause of much mischief. When the char cisterns of a refinery are to be washed off hot water is run on while the heavier syrup descends and is drawn off below. But the two liquids commingle to some extent and a weak solution of sugar is formed which is exceedingly liable to fermentation. The free oxygen in the washing water under the influence of the charcoal appears to act upon the vegetable albumin which the charcoal has extracted from the sugar converting it into a ferment which quickly changes the sugar into lactic acid and this acid dissolves from the charcoal lime and traces of iron.The consequence is that the char washings are sour and putrid and highly charged with salts of calcium besides which they frequently smell perceptibly of hydric sulphide. The ordinary way of getting rid of these washinq is to use them for dissolving fresh sugar but no greater mistake in sugar refining than this could be made As regards the temperature best adapted for the action of charcoal on sugar experience has shown that the liquor in the blow-up pans should be run off at 180' F.the char cisterns should have a temperature of about 155' and never below 150° and the water used for washing should be absolutely boiling. The quantity of water employed in the process of rehing is say for 100 tons of sugar something like this :-for dissolving 50 tons; for washing to produce sweet washings to be after- wards boiled down or used for dissolving 40 tons ; for washing the charcoal to purify it further 125 tons-in all 215 tons or nearly 50,000 gallons. I consider this the minimum quantity ; an additional amount of washing is invariably attended with increased excellence in the quality of sugar turned out. Revivifying of the Charcoal. The re-burning of charcoal in order to restore toit the power of absorbing colouring matter and other impurities is perhaps WALLACE ON THE CHEMISTRY OF SUGAR REFINING.119 the most important process in sugar refining. The object to be attained is to carbonize the organic matter extracted fkom the raw sugar so far as it has not been removed by washing. The process should be economical as regards fuel; it should allow of tfhe complete carbonization of the organic matters; it should permit of the ready escape of the gases and vapours produced; and it should expoae the charcoal for only the smallest possible length of time to the heat required for car- bonization so as to avoid the contraction of the pores of the charcoal besides other evils that result from overburning. There are two distinct kinds of reburners; those in which upright pipes are used and those which consist of hoiizontd revolving cylinders.The kiln hi general use consists of a series of upright; cast- iron pipes arranged in six rows of about ten pipes each row three rows being placed on each Ride of the furnace. The flame of the furnace plays directly upon the pipes and the pro-ducts of combustion are conducted away from the sides of the kiln. The wet char as it comes from the cisterns is placed upon the top of the kiln and sinks gradually down as the burnt char in the pipes is allowed to fall into the cooling boxes below. These consist of sheet-iron vessels the same length as the row of pipes to which they are attached about six or eight feet deep and an inch or three-quarters of an inch wide and cooled simply by contact with the atmosphere.The cooled charcoal is drawn from the cooling boxes every twenty minutes in such proportion that it is about six or eight hours in the pipes altogether. The time gven should depend upon the heat of the kilns and different quantities should be drawn fiom each row of pipes according to the amount of heat they receive from the fire. Thus if there are three rows of pipes the one nearest the fire should be emptied in about 5 hours that in the middle in 73 hours and the back row in 10 hours. These kilns although tolerably economical as regards fuel are open to many objec- tions not the least of which is that the wet charcoal above pre- vents the fiee escape of the gases and vapow evolved from the carbonizing and drying charcoal.Of the heat consumed in the kiln four-fifths are absorbed in drying and it is a great mistake not to dry the charcoal wholly or partially before putting it into the kilns. I cannot occupy more time with further details of the various mechanical arrangements which have been adopted by various sugiir rcfiners nor with the description of 120 WALLACE ON TKE CHEMISTRY OF SUGAR REPUTING. the various forms of revolving cylinder-kilns information about which will be found in my paper on charcoal previously referred to. When the charcoal is sufficiently cold it is again placed in the cisterns and the whole process is repeated. Evaporation of the Liquor. The next process in sugar refining is the boiling down of the decolorized liquor so as to recover the sugar in a cryatalline form.This as is well known is effect>ed by means of a vacuum pan in which the vapour that is formed is condensed by jets of water and thevacuum is maintained by means of an air-pump. A pan of good size is 10 or 12 feet in diameter and may hold about 20 tons of sugar and syrup. The boiling down occupies usually about two or three hours; the extent of vacuum averages in a well made pan about 28 inches and the tempera- ture is usually 120’ F. at the beginning of the boiling and about 130’ at the end of the process. The improvements intro- duced of late years into the vacuum pan consist in increasing the extent of heating surface and the quantity of water injected into the condenser and in enlarging the neck of the pan to 18 inches or even more so as to permit of the free escape of the vapour into the condenser.The operation commences by running into the pan a quantity of liquor s&ciel;t to cover the first coil of steam pipe or ‘‘ worm,” when the steam is turned on and the boiling commences. After a time more liquor is run in and go on a little at a time until the pan is full the different tiers of worm being supplied with steam as soon as they are covered. At the very first the liquor is boiled strong enough to form a tb grain,” consisting of almost microscopic crystals of sugar and these increase in size as the boiling proceeds until at the finish they are as large as may be desired. It requires a considerable amount of training and skill to boil sugar so that the grain may be gradually built up.What is called false grain consists of a mass of minute crystals collected into grains and although in some cases this kind of compound crystal results fr9m the carelessness or want of skill of the boiler in other iiistances it is made intentionally so as to give the resulting sugar a whiter appearance and to enable it to hold more syrup. When IYery large and distinct cfystals are deaired such as WALLACE ON Tm CmWSTRY OF SUGAR REFINING. 121 are made in Bristol and Glasgow a modified arrangement is adopted. The liquor is boiled more slowly and at a higher temperature and when the pan is full the whole contents are not drawn off but onlya half and this is repeated several times the crystals becoming larger every time.The large crystals are much prized on account of their beauty and purity but they have the disadvantage of being troublesome to dissolve while the manufacture of them necessitates the exposure of the syrup with which they are mixed for a long time to a rather high temperature (about 160’) causing the conversion of a con-siderable portion of sugar into the uncrystallisable form and also darkening the colour of the syrup. And here I wouldgive a word of advice to refiners who all insist that in order to obtain large crystals a high temperature must necessarily be employed. I believe this to be a mistake. If sugar requires a high temperature to form large crystals it must be different from all other crystalline bodies; and besides sugar candy is formed at a low degree of heat and consists of larger and more distinct crystals than ever were formed in a vacuum pan.Large crystals must be formed slowly and the degree of heat is I believe a matter of indifference. Strange to say I have not succeeded in inducing any refiner to boil slowly and at o low temperature. They all say that it cannot be done and so the matter rests. The mistake they makeis that they regulate the rapidity of boiling not by the quantity of steam admitted to the worm but by the quantity of injection water so that when the latter is diminished the extent of x-acuum is lessened and the temperature necessarily rises while the steam not escaping readily retards the process of evaporation.If on the other hand the maximum quantity of injection wdter were maintained and the amount of steam diminished the boiling would be as slow as inight be desired while the loss to the refiner by exposing the syrup to a high temperature would be avoided. In boiling down the syrup obtained from the drainage of the first crop of crystals less care is required a small grain being preferred on account of carrying more syrup than a larger grain. In boiling the lowest grade of syrup it is customary to make what is technically called a “jelly,” in other words the formation of grain is entirely avoided and the result is left for several days intanks in order that crystals may form. There are generally three qualities of crushed sugar made viz.,whites mediums and yellows the white8 constituting nearly half of the entire produce ; but the proportions of the different kinds vary to some extent with the kind of raw sugar employed.The total produce of 100tons of raw sugar should not be less than 95 tons. The separation of tlie crystals from the syrup with which they are mixed is effected in an apparatus called a centrifugal machine which is simply 8perforated basket revolving at great apeed so that the periphery travels at something like 100 miles an hour. The drainage of the crystals occupies from three to twenty minutes according to quality and in the case of the finest and whitest variety a dash. of cold water is sometimes given in order to wash off the adhering syrup.And now I must bring my lecture to a close and have to thank you for the kind attention you have given to the sub- ject. Ifeel that I owe some apology to the scientific chemists present who must have listened I fear with impatience to details iu which they can have felt little interest. I have endeavoured to avoid mechanical details as far as possible while trying at the same time to exhibit a connected view of the whole process; and to the sugar refiners who have favoured me with their presence I have to say that it is impossible in a single lecture to give anything like rz complete description of all the improvements that have duriug the last few years been intro- duced much less to describe the results of the investigations connected with this branch of industry with which I have been engaged.The field of inquiry is one that is sure to be fruitful of valuable result8 to any careful observer and I trust that my few remarks if not. otherwise useful may at least have the effect of attracting attention to a subject of great importance. At the conclusion of the lecture the Pr esiden t directed attention to the observations that had been made on the con- densation of the charcoal in re-burning. He observed that charcoals not containing phosphate of lime if they are subjected h a long-continued heat-which need not be very intense- eadually contract and become quite hard. He had found from his own experience that charcoal which has been produced in a very light and porous condition gradually contracts on long exposure to heat just as gold precipitated in the porous state by a ferrous salt becomes compact and acquires a metallic ap-pearance if heated far below its melting point.WALLACE ON THE CHEiWSTRY OF SUGAR REFIXIKG. 123 The use of lime in sugar refining really appears to bring the sugar into an uiicrystallisalole state and the power of crystallisation is not restored by addition of an acid though it is recovered spontaneously after a certain time. The action both of acids and of lime and alkalies appears to destroy the crystallisability of the sugar and therefore an excess of either should be avoided. In connection with the decolorization of sugar which appears still to be entirely dependent upon the absorbing power of animal charcoal the President directed attention to the great absorbing power for colouring matters possessed by sulpliide of lead as observed some years ago by himself in the case of a solution of cochineal &om which it entirely removes the colour- ing matter although he by no means intended to recommend such a substance for use in sugar refining.Dr. Hugo Muller said that the sulphide of lead cannot be used with advantage in liquids like sugar; indeed Dr. Scheib- ler has recently found that it is dissolved and retained by several liquids of that kind and cannot be separated from them after wards . Mr. Pearson stated with reference to the quantities of sugar imported into this country that Holland as well as France sends large quantities and that unrefined as well as refined sugar is abundantly introduced.He mentioned the case of a sugar refiner in London who about a year ago was refining at the rate of 400 tons per week of beet-root sizgar imported from the Continent. With regard to the washing out of the charcoal Mr. P e ars on observed that in the north where there is an abundant supply of pure water this process may be carried to a very great extent ; but in the south where the waters those of the metro- polis for example generally contain a considerable quantity of calcareous salts a limit is very soon attained the charcoal after a certain time actually abstracting these earthy matters from the wateq which consequently runs off purer than when it is put in.The President enquired if any gentleman present could inform the meeting whether the colour-absorbing power of animal charcoal remains the same aft,er the phosphate of lime contained in it has been removed by hydrochloric acid ? 124 WALLACE ON THE CHEMISTRY OF SUGAR REFINING. Dr. Hugo Muller said that he had found from his own ex-periments in filtration that the pure charcoal though actually stronger in its action than the ordinary bone-charcoal is not so in proportion to the quantity; in fact that the same quantity of charcoal when the bone-phosphate is removod from it is not so strong as if it contained the bone-phosphate. Mr. Williams said that he could fully corroborate this state- ineiit fiom repeated expeiiments of his owii ; that though the pure charcoal will of course do more than the common charcoal bulk for bulk there is no comparison in the real percentage action of the carbon in each case.Dr. V o el c ke r asked for information respecting experiments made by Mr. Beanes on the decolorizing effect of ozone upon sugar. Mr. B e a n e s replied that the ozone process is not yet sufficiently advanced to enable him to speak positively respecting it ; but that so far as his present experience goes ozoiiized air passed through a coloured syrup for three hours exerts a decolorizing action as great as that obtained by leaving the sugar in contact with animal charcoal for twenty-four hours. Professor Williamson observed that one of the most iin- portant points which have lately occupied the attention of sugar refiners is the relation believed to hold good between the quantity of solnble salts in the unrefined sugar and the quantity of crystallisable sugars retained by them in the mother liquid and prevented from crystallising.It is custornaiy now to estimate the quantity of such salts in the sugar and to deduct a proportionate quantity of the sugar as being unavailable. From experiments made in his own laboratory by a gentleman occupied in the matter it appeared that some salts possess the property of retaiiiiiig sugar in solution as such while others Beem to possesa the opposite property actually accelerating the separation of the sugar. Dr. Voelcker mentioned that beet-root sugar generally con- tains a considerable quantity of chloride of sodium and yet no fruit-sugar is found in it,whence it seems to follow that chloride of sodium has not the power of changing the nature of the sugars.That it to a great extent prevents the crystallisation is however a well-known fact ; indeed sugar-refiners dread the presence of common salt in their sugar8 more than that of almost any other salt.

ISSN:0368-1769    

DOI:10.1039/JS8692200100

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

125 IX.-Cjn Catlmrism or the ihJuence of Chemically Clean Surfaces. By CHARLESTOMLINSON, F.R.S. F.C.S. I PROPOSE to commence this lecture with an account of Borne experiments and remarks By three distinguished observers whose names. cannot fail to be received with respect in the Chemical Society. I refer to Oersted Schonbein and Liebig. As long ago as the year 1805,O erst ed published an account of an experiment* in which a solution of a carbonated alkali was filtered into a cylindrical glass not too narrow and upon this with the Leak of the funnel just touching the alkaline solution wa8 delivered drop by drop some dilute hydrochloric acid. At the moment when the acid drops touched the alkaline solution there was a slight effervescence but the gas was given off from the sidea of the vessel at the boundary line of the two liquids.Dilute sulphuric nitric or acetic acid might be used and the alkaline solution might be that of carbonate of potash of soda or of ammonia care of course being taken that the acid layer was of less density than the alkaline. Or a dense acid solution might form the bottom layer and a less dense alkaline solution might be filtered upon this until the volumes of the two liquids were about equal. The two strata remained quite distinct as was seen by colouring the acid red and the alkali green. The acid aiid the alkaline solutions could also be separated by means of a layer of water in which case there was little or no effervescence on filtering the acid upon the alkali or the alkali upon the acid.The liquids were ta be filtered into the centre or along the axis of the jar. If the funnel were so inclined as to make the drops trickle down the side of the jar there was a brisk effervescence. But if the experiment were properly conducted there was no escape of gas after the &-st slight effervescence. The glass might be left undisturbed during many hours without any ap- pearance of gas but the moment a solid was introduced such as a platinum wire a glass rod a bit of' shell lac the finger or any minute speck of solid matter such a solid not only be-# Ciehlen's Journal i 276 VOL. XXII. L TOMLINSON ON CATBARISM cttme instantly covered with gas but discharged gas briskly fiom its surface. Oersted put hia tongue into the jar and on examining it before a looking-glass saw that it was covered with gas-bubbles.He also perceived the taste of champagne and he argues that the tongue is efficient in separating gas fiom creamy wines. He also drew a much wider conclusion from his experiments namely that gas in solution is never given off except in contact with a solid. In order to see whether any rise of' temperature accompanied the escape of the gas 0erst ed put a thermometer into the jar; the bulb and the whole of the immersed portion of the stem were instantly covered with gas. There was no rise in temperature but thinking the thermometer would be more sensitive if' covered with silver wire he was surprised to find that the wire liberated gas even more abundantly than did the thermometer.There was however no rise in temperature. 0erst e d confesges that he cannot account for the connection between a solid and the liberation of gas from solution but he calls to mind many examples of such an action as when water is put under the receiver of an air-pump and the air exhausted the sides of the vessel become covered with globules of air and if a platinum wire be put into the water this too is simi- larly covered. So also if a little dilute spirits of wine be poured into fuming nitric acid and a glass rod be inserted gas is given off fiom its surface and still more abundaiitly from a platinum wire. Or if a little dilute hydrochloric acid be gently delivered to a solution of potassium sulphide there is scarcely any escape of gas or smell of hydro-sulphuric acid until a platinum wire is inserted and then the gas is given off abun- dantly.He further remarks that every one knows the influence of a solid on the crystallisation of saline solutions and also that water cooled below its freezing point instantly becomes solid when touched. Bla gden found that perfectly clean water was not readily frozen but water containing particles that diminished its clearness passed intv the solid state with ease. Liquids that are set aside to ferment do not begin to give off gas until they become clouded with solid particles; if these be removed ths fermentation ceases. In the effervescent drink made with carbonate of potash and citric acid the two solutions mixed in a large glass give off but little gas until stirred with a solid.If not stirred the mixture even after standing 24 houm will OR THE INFLUENCE OF CHEMICALLY CLEAN SURFACES. 127 enter into bi-isk effervescence if poured upon the surface of a linen filter. Thus far Oersted. In 1837 Schonbein published a number of facts pointing in the same direction as those contributed by 0erst ed." He says that in the formation of gas or npour in liquids certain physical circumstances have an influence and may even produce decomposition ; as for example when a solid is put into a solution of nitrous acid or into nitric acid con- taining some of the lower oxides of nitrogen. If such acid be covered with a layer of water and a platinum.wire be passed down to the boundary of the two liquids a lively effer- vescence takes place nitric oxide being liberated. Gas is also given off abundantly when copper brass iron or silver wire is put into so dilute a solution as one part of nitrous acid to ten parts of water. The escape of gas is far too copious to be ac- counted for by chemical action ; indeed there is no such action for there is not only no rise in temperature during the strongest effervescence but actually a slight fall. Moreover a bit of pine wood liberates gas with nearly as much energy as a brass wire but if the wood be deprived of air by long boiliug it becomes inactive. It is he says of importance to the interests both of physics and of chemistry to be able to explain these phenomena.It seems likely that the solids act by carrying down air into which the gas expands and that when deprivedof air they are inoperative. In 1839 Liebig while giving the details of an analysis of a mineral water,? noticed some phenomena connected with the liberationof gas from solution by the contact of solids as when sugar is thrown into a mineral water containing much gas it produces a lively effervescence; or if a stoneware bottle filled with such water be well shaken so much gas may be set free as to drive out the cork; 80 also if the mouth of a glass containing an effervescent wine be suddenly struck with the palm of the hand a foam appears on the surface. In all these cases air plays an important part. There is air in the pores of the sugar there is air in the stoneware jar which by shaking,mingles with the water and air also is driven into the wine by the sudden blow of the hand.Now taking into account the relative solubilities of air and of carbonic acid gas it * Poggendorffs Annalen xl 382. .t. Ann. Ch. Pharm. xxx 13. L2 TOMLINSON ON CATHBRISM follow that for every cubic inch of air driven into the water twenty cubic inches of carbonic acid will be set free. Such are the facts and remarks contributed by three first rate observers in science. Similar facts may be multiplied iiot only as it relates to the liberation of gases from solution but also of vapour from boiliug liquids and the crystallisation of saline solutions. Thus in the Scotch distilleries in converting the ‘‘wash ” into ‘‘low wines,” it is customary to throw a lump of soap into the still every time it is charged.The effect is to cause the slteam to rise quietly. The sugar-boilers also are accustomed to throw a lump of butter or of paraffin into the vacuum pan for the purpose of preventing that irregular kind of boiling which displays itself in furious bursts separated by almost passive intervals. It is also a usual practice in the laboratory during distillations to introduce into the retort solid matter such as eharp or angular pieces of metal glass &c the points being supposed to favour the generation of steam and prevent soubresauts or jumping ebullition. So also in crystallisation on a large scale strings stretched acrogs the vessel or a cinder thrown in favour the formation of crystals.But whether gas or vapour or salt escape fiom solution the influence of Bome mysterious function in the air is asserted by most writers. Thus Le Grand.,* who paid great attention to the phenomena of boiling says as De Luc had done half a century before that as Boon as the liquid water for instance has discharged all its air the boiling becomes difficult and irregular; indeed De Luc denies that water can boil at all if completely purged of air. Le Grand referring to the use of platinum for preventing bumping on account of its unalterable character says it is a mistake to employ that metal for as soon as the air introduced by it is expelled by the heat the bumping is renewed.He recommends zinc or iron-metals that decom- pose water with the greatest facility-and of the two zinc is to be preferred. Writers also frequently refer to changes in the molecular condition of the vessels containing gaseous or saline solutions or boiling liquids to account for unexplained phenomena. The idea originated wit8h Gay-Lussac in his paper published in * Ann. Chim. Phys. Iix 426. OR THE INFLUENCE OF CHE~CALLY CLEAN SURFACES. 129 1817,” on the shifting of the boiling point of liquids under a constant pressure in vessels of different materials. He imagines the boiling point to vary with the nature of the vessel and in the same vessel with the condition of its surface its degree of polish and also its conducting power for heat.The cohesion or viscosity of the liquid and its adhesion to the sides of the vessel must also exert an influence on the boiling point. So also in 18197 he explained the state of supersaturation of sodic sulphate on similar grounds such as the nature of the con- taining vessel its state of polish its conducting power the influence of electricity and a particular disposition of the saline molecules by virtue of which they resist more or less their change of state. Gay Lussac exerted so powerful an influence on the scien- tific mind of France that any suggestion thrown out by him took deeper rout than he perhaps intended. Moreover he was a man of lively imagination and inventive power and would readily throw off half a dozen suggestions to account for phenomena that were not clear to him without always stopping to test these suggestions in the crucible of experiment.But later observers with less invention regard these suggestions thrown off so carelessly by Gay-Lusgac as pearls of great price and estimate and cherish them as the talismans which are to explain some of nature’s mysteries. One of the greatest authorities on the subject of super-saturated saline solutions is the French chemist Liiwel who devoted eight or nine years of conscientious labour to the study of this subject the result of which is given in six elaborate memoirs,$ in all of which he relies upon a theory of molecular changes to account not only for the leading phenomena of supersaturation but also to explain many anomalous cases and this theory was applied as well to the solutions themselves as to the sides of the vessels containing them.Thus to select two or three passage out of many he says- ‘‘I think that at these low temperatures the inner surfaces of the tubes and flasks usually reassume their active or dynamic property of determining crystallisation which heat had de-prived them of.” Again he says with reference to the formation of the modsed salt :-* Ana Chim. Phys. vii SOT. tIbid. xia296. t Ibid. 1850 to 1857. TOMLINSON ON CATHARISM LLThereis every reason to believe that the walls of the vessel do not perfmm a merely pamive part.” And again- ‘‘Such solutions remain supersxtumted until in consequence of lapse of time and abovc! all of low temperature the inner surface of the phials have recovered that particiilar property of determining crystallisation of which heat had deprived them the cause of which is unknown to us.” Lowel also regards the functions of nuclei in determining crystallisation.“as the effect of one of those mysterious contact actions known a8 catalytic of which science has not yet been able to give a satisfkctory explanation.” I cannot help thinking that of iate years the terms C‘mole- cular change,” 66 molecular force,” ‘(molecularity,” &c. have been applied to phenomena in physico-chemistry without always sufficient cliscrimination. As used with respect to n large class of phenomena such terms do not advance our knowledge at all and every time we displace the word “molecular” by a simple common sense explanation of the phenomena in hand we per- form in my opinion a real service to science.Of the varied examples which I have thus selected from the labours of others Oersted gives no explanation at all; Schonbein accounts for his facts by reference to the action of the air which however he thinks insufficient; Liebig en-deavours to explain the phenomena brought forward by him by meam of the displacing power of common air over carbonic acid but for this he gives no experimental proof; Gay-Lussac offers a number of suggestions by way of explanation of his facts and from him Lowel and others have derived the idea of 6cmolecular change,” and from Berzelius t.hat of i4 catalysis.” In appearing before you to-night with a new scientific term I may seem to be guilty myself of the fault which I condemn ill others.But I venture to submit that if the term b6molecular change” is according lo my view a vague one in physico- chemistry the term “catharized condition ” has at least the merit of clearness. The Greek word lcaeupos signifies ‘6 pure ” or LL clean,” bnt the cleanliness of matter implied bF “catharizedn is very different from what is usually understood in the ordinary application of the word ‘‘clean.” 0erst ed found his finger act as a nucleus in liberating gas from solution but no amount of cleaning would have made it otherwise than uclean OR THE INFLUENCE OP CHEM~CALLYCLEAN SURFACES. 131 in the sense now intended.But if Oersted had cleaned his glass rod or platinum wire in a caustic alkaline solution or in sulphuric or nitric acid and rinsed it well in clean water he would have catharized it or made it chemically clean and it would then have no longer liberated gas from his solutions or salt from supersaturated or other solutions or vayour from a liquid at or near the boiling point. When bodies act as nuclei in separating gas or salt 01' vapour from solution it is because the gas or the salt or the vapour has a stronger adhesion to or attraction for the surface of the nucleus than the liquid portion of the solution has for such surface. If the nucleus be chemically clean there is no appreciable difference between the adhesion of the gas a'nd such surface and the liquid that holds the gas in solution.Hence there will be no separation of gas because the solution adheres perfectly and as a whole to a catharized surface. Bodies that are exposed to the air and to the products of respiration and of ordinary combustion that are handled or wiped with a cloth contract more or less of a greasy film which lessens the attraction between the liquid portion of a solution and such surface while the attraction between the gas &c. of such solution remains the same as before. Hence there is a separation of gas &c. from solution since gas or salt or vapour will adhere perfectly to a greasy surface and the attraction between such a surface and a gas is so strong as in some cases to produce chemical decomposition as when chloride of nitrogen is touched with an oily or greasy surface.The dust of a room which is constantly floating in the air is more or less contaminated with greasy or organic matter and acts as a nucleus. If such dust be collected on a filter and washed with a solution of caustic potash rinsed with water and dried out of contact with air it ceases to act as a nucleus. A nucleus then may be defined as a body that has a stronger adhesion for the gas or the salt or the vapour of a solution than for the liquid which holds it in solution. I believe this new principle of catharism is sufficient to gene-ralize and account for in a scientific manner the numerous facts already introduced to your notice. When Liebig shook a bottle half full of a carbonated mineral water the gas was liberated by coming into contact with the unclean sides of the vessel.When he struck his hand on a glass containing sparkling TOMLINSON ON CATHARISM Moselle or other gaseous wine he not only precipitated Borne of the unclean dust of the air upon it bnt he also shook the wine against the unclean sides of the glass. If a bottle of soda water be gently poured into a cutharized glass not a sinyle bubble will become attached to the sides. If water in n similarly clean glass containing a clean glass rod or wire be put under the receiver of an air-pump and the air be exhausted not a single bubhle of air will attach itself to the sides of the vessel or to the glass rod or to the wire. When Schijnbein found a bit of pine wood by long boiling inactive in liberating gas from solution it was not that the boiling had driven the air out I of the wood but that the boiling had catharized the wood.There is not a greater mistake than to suppose the air to have an influence in setting gas or salt or vapour fiee from solution. When air appears to act it is merely as a carrier of some unclean mote or speck of dust that ifi floating in it. And this explains the fact noticed by Low el and others that supersaturated saline solutions can be kept longest without crystallising in narrow- necked vessels the time being long in proportion to the narrow- ness 80 that if the mouth of a vessel be contracted to a capillary bore the solution can be kept as in a close vessel.I have found that highly charged supersaturated saline solutions in wide-mouthed flasks can be opened in a garden or a field in the country where the ah is free from the dust and motes of a room and be kept open for a long time without crystallising and when crystallisation does take place a nucleus is to be found in the shape of a small fly or other unclean objecf. By attending to this principle ofcatharism we may be able to account for and to eliminate those anomalous cases of crystal-lisation which have given rise to such terms as ‘‘ the mysterious action of the air,” “ the altered molecular condition of the sides of the vessel,” ‘‘ the molecular change which takes place in the solution,” &c. Previous obscrvers are I believe agreed as to the sensitiveness to cold of supersaturated saline solutions.According to them there is no separation of salt from solution during the summer months but the first touch of autumn’s or of winter’s cold immediately produces a deposit of salt. Hence according to Lowel whose view is generally adopted a super- saturated solution of the ordinary ten-atom sodic sulphate undergoes no change so long as the temperature is about 60”F. ; but below this it undergoes a molecular change and assumes the OR TRE INFLUENCE OF CEEMICALLY CLEAN SURFACES. 133 constitution of the more soluble seven-atom hydrate. Hence he ingeniously argues that supersaturation is a phenomenon in ap- pearance only and not in fact for the solution is but an ordinary saturated not supersaturated solution of the rnore soluble seven-atom hydrate.Why I have had highly charged super- saturated solutions of sodic sulphate (five salt to one water) in catharized tubes in freezing mixtures at 10' F. for hours to- gether without any separatioh of the salt ! And this observation applies not to sodic sulphate merely but to a number of other salts that form supersaturated solutions. Highly saturated boiling solutions of sodic acetate of sodio -potassic tartrate of sodic arseniate of potash alum &c. may be cooled down to near the zero of Fahrenheit wit'hout showing any gign of crystallisation. A salt of greater solubility is not formed and the state of supersaturation so far from being one in appearance only and not of fact is one both of fact and appearance.Take the case of potash alum. This is one of those salts which according to some observers throws down crystals in abundance when a hot saturated solution is left to cool in a close vessel. This is a true observation if the experiment be conducted in a vessel that is not chemically clean but if a strong solution of alum (3$ salt to 1 water) be boiled in a chemically clean flask and then filtered into a similar flask boiled again and a plug of cotton wool be fitted into the neck not only will such a solution cool down to the temperature of the air without any separation of the salt but the flask may be kept in a freezing mixture of ice and water for hours without any sign of crystallisation although the solution contains upwards of sixty times more salt than the water can take up at the reduced temperature.It was not known that the inner surface of a chemically un- clean flask acts as a nucleus on the solution as it cools down. L6w el often noticed the embarrassing fact that at low tempera- tures the sides of his flasks appeared to regain the active con- dition that heat had deprived them of and seeing that the glass rod and other solid nuclei which had been rendered inactive by means of flame or by long immersion in water and cooling or drying out of free contact with air became active by exposure to the air he naturally attached some mysterious property to the air yet to be discovered. All these anomalies disappear by making use of chemically cleau flasks with carefully filtered TOMLINSON ON CATHARISM solutions.The state of supersaturation then resolves itself in the majority of cases not into the formation of a more soluble salt but into a case of no nucleus in fact into the absence of any predisposing cause that influences crystallisation. We must even modify our ideas as to the influence of low temperature in inducing crystallisation. I think it a remarkable fact that alum for example of which 3.9 parts dissolve in 100 of water at 32' F. and 357.58 parts in the same quantity of water at 212O should allow a solution containing upwards of 60 parts more salt than it can dissolve at 32" to be cooled down to that point and even below it without any separation of the salt.And this is not a state of unstable equilibrium which it is difficult to maintain for such a solution in a bottle half full of air can be violently shaken or kept for a length of time without change or put into freezing mixtures or be exposed to various vicissitudes of temperature. It had not been hitherto supposed that highly saturated solutions could thus be made independent of low temperature. Since LOwel's time the course of inquiry has been chiefly directed to ascertaining the real function of nuclei in inducing cry stallisation. Solid bodies have been ex- amined by hundreds in the hope that in this multiplicity of examples a few might be got to speak the truth. My own labours in this direction conducted during a long period with a great respect for the authority of Lowel and others led to very contradictory results.By slow degrees it began to dawn upon me that in the simplicity of nature's dealings a slight difference in the force of adhesion between the nucleus the solvent and the thing dissolved was sufficient to explain the matter. A great many salts form supersaturated solutions. Only a few produce the modified salt of a lower degree of hydration and of greater solubility than the normal salt. My explanation ofthe formation of the modified salt when it does occur has already been published in full elsewhere,* but I shall have occasion to describe it in brief presently. In the mean time I may be allowed to remark that if Lowel's molecular theory were true,it ought to apply to all salts that form supersaturated solutions.Indeed it is so applied by L Owe 1's followers and they explain supersatnration by supposing the molecular character of every solution to change on a certain depression of * Phil. Trans. for 1868 page 666. OR THE INFLUENCE OF CHERIICALLY CLEAN SURFACES. 135 temperature so as to assume the condition of greater solubility of the more modified salt. Lowel in the course of his long inquiry extending as it did over eight or nine years never succeeded in showing that more than about three salts formed the more sohzble modified salt and his followers have done nothing to add to the nnmber. Anomalous cases occur which cannot be explained except in a way which seems to me to be fatal to the tliemy.For example to notice only one such case. Lowel poured a strong boiling solution of sodic sulphate into two bottles of the same size wliich were then tightly corked and set aside to cool under apparently the same conditions. The solution in one of the phials deposited the modified seven-atom salt while the solution in the other became solid throughout as the normal ten-atom hydrate. Lowel .supposes that in one case the solution did undergo the molecular change which led to the formation of the seven-atom hydrate while in the other case from some cauBe or other the molecular change did not take place. My explanation is this :-The one bottle was cleaner than the other or was made so by the hot solution. As the solution cooled down it deposited the excess of anhydrous salt which it could no longer hold.The heat thus liberated and also a rise in atmospheric temperature after sunrise caused the anhydrous salt to re-enter into solution and to form a dense lower stratum from which the seven-atom hydrate in small quantity crpstallised out there not being sufficient water in this dense stratum to form the ten-atom hydrate. In the other case the solution during the cooling met with a nncleus high up in the bottle to which the salt could attach itself and the action once begun in the presence of a nucleus was propagated rapidly throughout the needles having suflicient or carrying down sufficient water to form in every part of the solution the ordinary ten-atom salt. Cases of this sort have repeatedly happened to me in the course of my investigations.If we open a flask containing a supersaturated solution crystallisation sets in at the surface consequent on the entrance of some speck of dust fkom the air and the needles proceed from the surface to the bottom solidifying the whole contents of the flask ; whereas the modified salt when it forms at all invariably does so in small quantity at the bottom of the flask while the superposed mother-liquor is still a supersaturated solution. If the flask be now opened the normal salt forms on the surface crystallisation TOMLINSCJN ON CATHARISM proceeds rapidly downwards and the needles seem to inter- penetrate the transparent modified salt giving it in the case of sodic sulphate three additional equivalents of water and rendering it opaque in the process.The action of nuclei explained according to my view with reference to gaseous and saline solutions applies equally well to the liberation of vapow from a liquid at or near the boiling point. Such a liquid may be regarded as a supersaturated solution of its own vapour. If the vessel in which the liquid is boiled be chemically clean or becomes so by the action of the liquid the vaporous solution adheres perfectly and completely to the sides but as the heat is continually acting the liquid becomes more and more saturated with the vapour until not being able to dissolve any mare it relieves itself by a sudden burst a,s from a safety valve. This sudden burst of vapour occasions the jumping or rebound of the vessel by a mechanical reaction.The burst of vapour follows the direction of the line of least resistance or upwards along the axis of the vessel; this produces an equal reaction in a downward direction which tends to force the vessel further into the ring of the retort stand and it is the rebound from this that constitutes the soubresaut or the phenomena of bunqhg or jurnpivig ebullition. This explanation which I venture to give may be tested by Buspending a flask or a tube by means of a spiral spring or a thread of elastic against a board with a line drawn horizontally from the mouth. If the vessel be chemically clean or contain one of those solutions which according to Le Grand favour the production of sobresauts it will be found on the application of a spirit-lamp that every burst of vapour is accompanied by a downward kick of the vessel.If with the view of prei-enting soubresauts we throw into the vessel a solid of any kind that has been handled or exposed to the air the violent action is got rid of because the vapour attaches itself to such solid with greater force than the liquid does so that under the action of the heat there is a constant liberation of vapour from the surface of the solid. But should the liquid be of such a nature as to bring the solid into a catharized condition the bumpings return with even more violence than before because we have now increased the adhesion surfaces instead of the vapour-giving surfaces. If instead of an unclean body we introduce a catharized body into a vessel in which a liquid is boiling with OR THE INFLUENCE OF CHEMICALLY CLEAN SURFACES.137 little or no bumping we may at once bring about such violent bumping as to endanger the safety of the vessel. A little sand steeped in strong sulphuric acid and well rinsed in water or in a weak alkali is sufficient for the purpose in a flask in which distilled water is boiling. Even the iron on the zinc so much insisted an by Le Grand as favouring tranquil boiling produce soubresauts if made chemically clean. Zinc however often contains minute specks of poroiis matter which act in another way as will be noticed immediately. It is said that pointed or rough bodies are better “promotere of vaporization” than smooth ones.Make them all alike chemically clean and they act alike in impeding rather than promoting the liberation of vapour. It is true that rough bodies are apt to store up between their furrows or teeth that unclean matter which acts so well as a nucleus. But if a rat’s tail file for example which is a very active nucleus in its ordinary state be catharized either by the action of flame or of acidand alkaline solutions it becomes perfectly inactive in a boiling liquid so far as the liberation of vapour is concerned. It will be seen that I take no account of the influence of the dissolved air upon the phenomena of boiling and so far from assigning to it the exalted function of being absolute17 neces- sary to boiling I doubt whether it has any influence at all except in some cases slightly to diminish the cohesive force of the liquid molecules but this effect must soon disappear.Water for example when cold dissolves only about &th of its volume of oxygen gas and about d,th of nitrogen and these small quantities must be expelled by the heat and the absorptive power of the boiling liquid for air reduced to a minimum. Can it be supposed that the minute speck of air still left if it be still left in the boiling liquid is absolutely necessary for the vapour to expand into and produce the phenomena of boiling 3 Can it further be maintained that when bodies act in preventing soubresauts it is by the air they carry down and that such bodies cease to act as promoters of vaporization when they have discharged all their air? I cannot admit that there is experi- mental proof for either assertion.A lump of flint that has been exposed to the air when thrown into a boiling liquid is instantly covered with bubbles of vapour. Break it into two and throw in the fragments not a single bubble of vapour will be seen on the freshly fiactured surfaces but the old surfaces TOMLINSOX ON CATHARISM will be covered as before. If air had anything to do with the matter the freshly fkactured surfaces must have carried down air as well as the old ones. Why then do the new surfaces apparently refuse to act while the old ones are as active as before ? We can explain nothing on this theory but if we say that the freshly fi-actured surfaces are chemically clean we can understand why no vapour is given off fiom them because there is perfect adhesion between them and the solution as a whole.There is thus far an identity of action in nuclei whether aa applied to gaseous or saline solutions or to liquids at or near the boiling point. I have now to iiivite attention to an exten-aion of the principle of adhesion consequent on the extension of surface presented by porous bodies. The same force which according to Saussure enables 1volume of box-wood charcoal to absorb 90 volumes of ammoniacal gas 85 of hydrochloric acid gas 65 of sulphurous acid gas and so on enables charcoal and some other porous bodies to absorb vapour from boiling liquids and under the continued action of the heat to give it out in never-ceasing jets relieving the vessel of all tendency to bumping making the boiling soft gentle and regular and increasing the quantity of the distillate.The most remarkable circmmstance about this property of charcoal is its untiring activity. No amount of heating or washing in acid or alkaline solutions suffices to cathaiize it. These processes seem rather to improve its strong attraction for gas or vapour in solution. When once in action it will continue for days and weeks together to give off vapour from the boiling liquid and unlike the soap paraffir, &c. used by distillers on the large scale for the purpose of facilitating the discharge of vapoui- the charcoal or other porous body 80 far as my experience goes does not require to be renewed.In order to show the value of charcoal and other porus bodies in preventing bumping and promoting vaporization methylated spirit was distilled in a glass retort at a fixed boiling point of 171' F. The distillate collected in five minutes was weighed and found to be 244 grains. Three or four fragments of char- coal part.ly from box-wood and partly from cocoa-nut shell altogether weighing 20 grains were now added to the retort and when the spirit wak again fairly boiling the distillate duiing five minutes was again collected and weighed. It was now found to amount to 325 grains. The ratio of the results OR THE INFLUENCE OF CHEMICALLY CLEAN SURFACES. 139 may be thus stated:-As 244 325 : 100 133.2. Instead of charcoal 20 grains of pumice-stone in four fragments were next used in the retort and the ratio of the result was as 100 121.7; with 20 grains of meerschaum-as 100 112 ; and with 20 grains of coke as 100 107.46.These numerical results are however very much under-stated if compared with those obtained in a retort that is structurally free from nuclei which was by no means the case with the retort actually used. Indeed is is seldom that we get a retort or a flask or even a test-tube that is free from porous specks of ferric oxide or of carbon. These become attached to the glass while it is still soft in the process of nianufacture and they act as small but powerful nuclei in promoting vaporization and preventing bumping. Indeed were it not for the presence of these accidental impurities many a chemical operation must fail fiom the fracture of the vessel by excessive bumping and chemists would have only too close an acquaintance with the phenomena of soubresauts.Several writers have noticed that when a liquid is boiled in a glass vessel the boiling seems to proceed from certain points in preference to othera. Donny calls them ‘‘ foci of vaporization,” and Magnus noticed in the case of an old platinum vessel containing cracks and scratches that the vapour was more readily formed at certain points than at others. These phenomena are perfectly explicable on the principle of adhesion on the part of unclean or porous bodies which having a stronger attraction for the gases or vapours than for the liquids which hold them in solution thus effect their separation.During the last seven years I have applied the principle I am now advocating to the phenomena of the cohesion figures of liquids ; to the production of camphor-currents and camphor pulsations ; to the motions of creosote on water and its dis- placing power with respect to various films ; to the adhesion of liquids to liquids ; to the curious attractions and repulsions of eugenic acid on water ; to the production of tears in the wine- glass and in solutions ; to the production of lightning-figures which illustrate some new points respecting the disruptive dis-charge and the formation of fulgurites ; to the effect of clean and unclean surfaces in vegetable nature such as the different action of the leaves compared with the roots of plants; why dew is formed in globules and not in sheets of water ; to certain 140 TOMLINSON ON CATHARISM phenomena connected with animal and vegetable secretions and so on.I will now with your permission glance at a few other phenomena which do not seem to me to have been hitherto explained. I think it was Sir Humphry Davy who found that in at-tempting to make a voltaic circuit with pairs of plates of metal of the same name there was no current while the metals were in the mme physical condition but that if one metal of the pair had its surface covered with a film of fatty matter a feeble current was produced. In such a cage the urrclean plate aeparated the gas &om the solution and was thus enabled to perform the part of the conducting plate.So also it was found that zinc tin iron and copper heated in the air until they had become tarnished were negative towards the bright metals of the same name in acid alkaline or saline liquids. In these cases also the plates covered with a film had a stronger attraction for the gas of the cell than for the liquid and thus relieving the cell of gas were in the condition to act as con-ducting plates. A plate of pure zinc is scarcely acted on by dilute sulphuric acid on account of the perfect adhesion of the acid to the clean mrface. Or if gas be liberated when the plate is first immersed it is fiom unclean patches or points but these soon becoming cleansed or catharizedby the action of the acid there is perfect adhesion between the acid and the p€ate and chemical action is arrested.The same remark applies to amalgamated zinc or to impure zinc covered with a film of mercury. The mercury makes the plate chemically clean and the adhesion of the acid is too close to allow of the escape of gas. Or if gaB form when the plate and the acid first meet the gas goes into solu- tion and this solution adheres with such force to the plate as to prevent the formation of more gas. So also in what is called the ‘‘passive ” condition of iron and a few other metals in nitric acid of the specific gravity 1.4 to 1.5 the principle of catharism coupled with the fact that the iiitrates of such metals require at least six proportionals of water of crystallisation which are wanting in the strong acid Beems to me to explain phenomena that have excited an unusual degree of discussion.Gmelin in his Handbook of Chemistry (Cavendish Society’s Translation) devotes twenty closely printed pages to Ihe mere analysis of what has been done on OR THE INFLUENUE OF CHEMICALLY CLEAN SURFACES. 141 the subject. He says :-“ Many metals when immersed in coil-centrated nitric acid undergo a change; they become more electro-negative less oxidizable and lose either wholly or for the most part their tendency to decompose acids and metallic saline solutions ; they pass from their ordinary active state into a passive state.” Passive iron for example will not separate copper from a solution of cupric sulphate or nitrate nor mer- cury from mercurous nitrate nor silver from argentic nitrate and so on.Strong nitric acid is so powerful a catharizer that it renders chemically clean an iron wire however dirty it may be when immersed in it and the acid adheres to it with such force that it is not readily displaced. I have transferred a bright iron wire from iiitrk acid of 1.410 sp. gr. to ah acid of 1.200 sp. gr. and it has remained for hours in a perfectly passive condition; but if shaken or rubbed beneath the surface of the acid it instantly starts into activity it changes colour and a brisk effervescence sets in with the abundant evolution of red fumes. In what is called a ‘‘ pulsating wire” gas is liberated in bursts separated by intervals of repose.This is similar to what takes place when a glass rod covered with an oily film is put into a strong solution of carbonic acid as in Oersted’s experiment. The gas that is liberated from the surface of the wire imme- diately enters into solution with the adhering acid (which must be diluted to a certain strength determined by experiment for the wire used). As more gas forins on the surface of the wire and the acid can hold no more that first dissolved is driven off with a burst ; it accumulates again again goes into solution and once more escapes with a burst and this intermittent action produces the phenomena called pulsation. The most common case of nucleus is when a body is contami- nated with oily fatty or greasy matter; but this does not render an iron wire active in strong nitric acid for such acid immediately acts upon and displaces the impurity and catharizes the wire.Iron wire covered with a chemically clean film of oxide which would be quite inactive in separating a salt or a gas from an aqueous solution is powerfully active in iiitric acid of a certain strength. So also if the inactive wire be put into chlorine or held in the vapour of bromine or in hydro- chloric acid gas it may be active for a time at least if returned to the nitric acid in which it was previously pasaive. The same VOL. XXII. M TOMLINSON ON CATHARISM result may be produced by rubbing the passive wire against a softer metal. I fear I have already exceeded the time allotted to a lecture in this place but perhaps a few worh may be allowed by way of conclusion.I trust I shall not be assuming too much if I claim for catharisrn the properties of a principle of nature namely generality and breadth of application. The principle is as yet new to science. The work that lies before us in connection with it seems to me to be of importance. I believe that the proper action of nuclei which this principle teacheb will explain the formation of agates arid other siliceouls minerals which is at present obscure. I believe that catharism will account for many if not for all the cases of increased activity consequent on the nascent state of matter. In that state matter is chemi- cally clean and hence is endowed with a wonderful activity and power of combiiiation; but no sooner does it emerge from the nascent state and come into contact with unclean vessels and unclean solutions than it sinks to the level of activity of ordinary matter.I believe that catharism is competent to explain many of the anomalies connected with ozone and the increased activity of oxygen at the sea coast or still better on the wide ocean. I believe that catharism explains why sulphur phosphorus and aorrie other bodies sonietimes remain liquid during a great length of time at ordinary temperatures; why water may be cooled below the freezing point as well as many facts in vegetable and animal physiol!gy that are at present not well understood. If health and eyesight are spared to me €or some time longer I hope to cortinue my explorations in this rich field of inquiry; but I shall require time for my meane are very limited and I have no assistant or assistance from any one.But if what I have done am doing and propose fo do is likely to be in any way conducive to the interests of science rriy reward has been already earned. DISCUSSION. The Pre sident observed that the genera1 conclusion deriv-able fi-om Mr. Tomlinson’s experiments appears to be this :-that there are certain bodies which have the power of causing the liberation of gase8 or salts &om solution and others which OR THE INFLUZNCE OF CHE3IICALLY CLEAN SURFACES. 143 have not that power ; a perfectly clean glass vessel for example does not appear to possess this power but there are certain substances which may overlie its surface and induce the par- ticular action in question ; but we have not yet discovered what it is that causes the separation of one body from another which holds it in solution.Charcoal even when made perfectly clean appears to possess this peculiar power in a very high degree. Dr. W. A. Miller said that Mr. Tomlinson’s observations seem to show that the principal agent in producing these singular phenomena is a film of grease which very generally adheres to the surface of glass vessels arid other bodies and disturbs the balance of adhesion between the solvent and that which it holds in solution. The experiments in question may not have brought us any nearer to the knowledge of the cir- cumstances which cause adhesion between two substances but they have at least enabled us to advance one step viz.that of tracing a comiderable number of widely scattered phenomena to one very generally operating cause. Professor Williamson with reference to the presence of air in liquids during their vaporization directed attention to the very remarkable observations made Borne years ago by Mr. Grove,” showing that water if carefully freed fiom air and excluded from access of air may be heated to the boiling point for a very long time without showing any signs of ebul- lition. We know that eveiy vapour is formed much more readily in preseme of a permanent vapour or gas than when no such gas is present and though it would be going too far to say that no ebullition can take place without air we have as yet no evidence that ebullition can take place if permanent gases are completely excluded.The effect of charcoal in facilitating the escape of gases from solutions is decidedly in favour of the view which regards the presence of a permanent gas as necessary to ebullition ;for charcoal retains gases within its pore@with great tenacity and even after it has been to a great extent exhausted of air it probably still retains quantities considerably greater than Mr. Grove found to be contained in the water with which he experimented. With regard to the term ‘‘chemically pure,” which Mr. Tomlinson uses to dis- tinguish bodies which do not exert this action from those which do Dr. Williamson said that he felt Borne difliculty in * Chem.SOC.J. [2] i 263. TOMLINSON ON CATHARISM this application of it since to take one example among others the crystallisation of R supersaturatt?d solution of sodic sulphate is brought about by contact with a crystal of the same salt more certainly and rapidly than by any other substance; now such a crystal cannot well be called chemically impure or nn- clean. Dr. Gladstone thought that Mr. Tornlinson’s researches had done good service in pointing outc the incorrectness of maiiy of the explanations that have bceii given of the phenomena under consideration particularly in showing that the Bmooth-ness or roughness of a surface has nothing to do with its effect in determining the separation of a gas or of a solid fiom a solution.This separation appears according to Mi*. T omlins011 to depend upon the fact that the nucleus or solid substance immersed in the liquid has a stronger adhesion to the dissolved gas or solid than to the solvent itself. This however is not a matter of cleanliness or uncleanliness and therefore in speaking of such matters it wonld be well to get rid altogether of the words “clea~ii” and “unclean.” A piece of paraffin may be made perfectly clean and yet it would certainly produce the effect of removing a salt froin solution. Dr. Gladstone also referred to the well known instance of t’he ci-ystallisation of potassium bitartrate when a potassium salt is mixed with tartaric acid and the sides of the vessel are rubbed with a glass stirrer the crystals then forming chiefly on the rubbed portions of the surface; this again is a case with which cleauliness or iincleanliiiess has nothing to do.The sudden crystallisation of a supersaturated solution on dropping iiito it a crystal of the same salt appears to depend on the strong tendency which a crystal has to draw to itself other particles of the same substance iu fact of the tendency of all crystals to grow aiid may therefore be regarded as affording a strong argument 111 favour of the general expla- nation above suggested. Professor A. Vernon Harcourt objected to the principle of the paper that it is purely a iiegative princ;ple namely that certain results do not occur in the case of the absence of a number of different substances that a minute quantity of these substances will produce the results and that these substances being diffused through the air and in the vessels we employ are very liable to pass into the eolution.The only positive result we could have on the subject would be h the OR THE INFLUENCE OF CEE~OALLY CLEAN SURFACES. 145 way of a determination as suggested by the President of what kind these substances are which do produce this result. We want to know for instance whether charcoal is a substance which produces it in the greatest degree or whether it is a general property of porous substances whether it depends upon the evolution of a gas or what the substances are to which these results are due. Professor Harcourt here referred to a recent observation of his own which appears to have a bearing upon this subject although the case is rather an exception to than an example of the general fact brought forward by Mr.Tomlinson. In determining the rate of the decomposition of peroxide of hydrogen he had introduced a meamred quan- tity of dilute solution into glass bulbs at a certain tempera- ture and then determined what amount of peroxide of hydrogen remained hoping so to ascertain what relation the rate of decomposition of the substance bore to the temperature to which it was heated and the concentration of the solution; but he found some difficulty in making these experiments and obtaining concordant results. Taking exactly the same quan- tities being very careful as to the temperature of the solution and the concentration and as far as could be observed having everything in the same way the quantity of peroxide decom- posed after the Bame length of time was found to differ very much indeed according to the glass bulbs employed; and the more pains he took in cleaning these bulbs by heating acids in them and by heating alkalies in them the greater and not the less was the amount of decompoaition.On examining the matter closely he observed the very greatest differences bet ween the amount of decomposition according as he took glass as thoroughly clean as possible or glass which was not clean. On taking a little oil and noticing what happened when the bulbs were made dirty in that way he found that the rate of decom-position was very much reduced indeed; and when the bulbs were varnished over inside so as to prevent the contact of the glass with the liquid the decomposition was reduced to a minimum.A dilute solution of peroxide of hydrogen in a perfectly clean glass bulb at 10" or SO" centigrade would be nearly decomposedin half an hour but would be hardly decom-posed in any degree if it was placed in a dirty bulb or in a bulb varnished inside. Decomposition of t3he peroxide of hydro-gen is very much like the solution of oxygen in water and the 3x2 3 46 TOAILINSON ON CATHARZSM rate at which the gas is given off in this caBe seems to be increased by the cleanliness of the glass and to be diminished when the glass is dirty. Dr. 0dl in g said that he felt some little difficulty in seeiiig his way clearly to the conclusion to which Mr.Tomlinson haB arrived.This conclusion appears to be that when a liquid containing a gas or crydallisable solid is in contact with a body of a particular kind the adhesion is not 80 perfect a8 in others and in that case either the gas is evolved or the crystals are thrown down. In the cases where the adhesion is perfect no gas is evolved and no crystal is thrown down and if this be the case it becomes a question with which minute division has very little to do. Taking the car;re for instance of the retoi-t to which Mr. Tomlinson has alluded we have there two different materials. We have the material which constitutes the great body of the glaaa and we have the material which constitutes the nucleus and under thoae circumstances it woiild perhaps hardly be a sufficient explanation to say that the adhesion of the glass is simply leas perfect to the nucleiis than elsewhere.Supposing we have a retort which is all nucleus under those circumstances the adhesion will be equal in every direction; nevertheless there would probably not be any points from which this evolution of gas could take place. Take the case of paraffin which Dr. Gladstone has alluded to. Now it is a common thing as Mr. Tomlinson said to throw grease into water in order to promote ebullition. Sup-pose we make a retort entirely of paraffin or one such as Mr. Harcour t haa jurrt described under those circumstancea the adhesion of the liquid however imperfect will be uniform and according to Mr.Tomlinson’s view there aeema no reaaon why the ready ebullition of a liquid of low boiling point due to the non-adhesion to the walls of the paraffin retort should ever Come to an end-why that is to say the efficacy of the paraffi or pure grease in promoting ebullition should be temporary only. With regard to the observations of Dr. WilliamBon respecting the great difficulty of removing the last traces of air fiom water Dr.Odling said that if he remembered Mr. Grove’~3 experiment accurately the amount of water given off gradually got less and less up to a certain point and then there was an almost constant ratio between the amount of vapour given off and the amount of gab and that ratio rtontinued no OR THE INFLUENCB OF CLEAN SURFACES.147 matter how long the ebullition was maintained. Related to this subject ie the fa& of many liquids which nevertheless there is reitsou to believe are not very absorptive of gaa boiling with very great facility auch bodiea as the hydrocarbons for instance ; but it is by no mean8 to be taken asa matter of proof that the quantities o€ gas retained by a boiling hydrocarbon may not be at least equal to those minute quantities of garr which are capable of being retained by water which has been boiled for a long tims With reference also to the question of charcoal if it be really the charcoal itself that has this ac~on the densest and most compact kin& of charcoal ought to amwer almost ag well as those which are more porous.Profwor Foster said that he was unable to we in any of the facts brought forward by Mr. Tomlinson a proof of the incorrectness of De Luc’s theory which supposers that the presence of air or gas of some kind or other is a necessary condition of ebullition. The different effect of a glaas rod when it hast been exposed to the air andbeen carefully cleaned and the different effects of other bodies under like conditiona Beem to resolve themselves simply into different degreea of facility with which they are wetted by the solution into which they are immersed. Now water cannot wet a body thoroughly unless it is able to &place the air which adheres to the body. If it does displace it then it wets it but the greasiness or whatever may be the condition of the surface acts in a great many cases at any rate by increasing the adhesion of the air or diminishing the adhesion of the water or liquid whatever it may be.It is very difficult indeed to form any clear idea of vaporization taking place in the midst of a liquid. If we try to form a definite idea of what the mechanism of vaporization is we must mmmo that it consists of such a motion of the particlesof the substance as drives them for an instant out of the spbere of attraction of the aeighbouring particles and when they once get to a certain distance from them the attraction of the remaining particles k unable to bring them back again. But if we take Clausius’s view of vaporization or any other equiva-lent to that it is impossible to gee how any such process could go on in the middle of a mass ofliquid; but if we take the amallerrt quantity of vapour already foimed or gas or the smallest possible quantity of vacuous space (of course a perfect vac~m would do ahl well if we could get it) then it ia easy to see how 148 TOXLINSON ON UATHARISM molecules should be driven by the increased action of their neighbours into thi8 space and liberated once for all from the attraction of their neighbours and thus appear as gas.Dufour found that liquids of very various character could be heated far above their boiling point if suspended out of contact either with solid wadls to which the gases might adhere or out of contact with the atmosphere but that an unfailing way of causing liquids in such a state when above their boiling-point to enter into ebullition was to send an electric current through them.If he had the wires of a battery projecting into the liquid a globule of liquid heated above its boiling-point and suspended in some liquid which did not dissolve it might come into contact with the wire with perfect impunity but if the battery contact was made so as to make an incipient decomposition and form a globule of gas rapid ebullition took place. Professor Foster further stated that in distilling liquids which one may suppose do not readily dissolve air in very large quantities for instance the iodides of methyl and ethyl he had noticed more than once that ebullition in the distillation of such a liquid ceases com- pletely without the evolution being much slower evaporation appearing to take place from the surface.All these facts seem to support De Luc’s theor?- and he copld not see that the facts brought forward by Mr. Tomlinson are sufficient to overthrow it. Mr. Heisch referring to Mr. Tomlinson’s attempt to explain the passive state of iron by supposing the iron had been rendered perfectly clean by immersion in strong nitric acid said we must remember that if we immerse but half an inch of a wire in strong nitric acid it renders any length of the wire perfectly passive to dilute acid. You may take 50 or 60 feet and provided you immerse the end in the strong acid the whole is rendered passive in the dilute acid and it is passive only to that same sample.But if you take another vessel and dip the wire into it the wire immediately becomes active in that vessel but not in the original nitric acid. More-over if you take pieces of iron wire bend them into a U shape and place one end in very strong and then in dilute acid that wire is passive. If you take another vessel and bring the other end of the U into it that part is active and dissolves completely. Then take another U and place one end of it first of all in the OR THE INFLUENCE 0%’CHEMICALLY CLEAN SURFACES. 149 glass in which the iron is being dissolved and then put the other end of the U into the glass in which it is not being dis- aolved and you will find that it is passive at oue end and active at the other.Rut if you reverse the experiment you make the whole perfectly active. NOW,it appears scarcely possible that the fact of the wire being cleaned by the nitric acid can explain these phenomena at all. Dr. F. Crace Calvert mentioned some remarkable facts relating to the sudden crystallisation of carbolic acid and of glacial acetic acid. Carbolic acid presents in a higher degree than acetic acid the curious property that it may be agitated with a stirrer or anything else or with dirt-with a solid or not-without undergoing crystallisation. In fact carbolic acid has been known to go all the way from Manchester to the south of France and reach there perfectly liquid; but on droppifig just one crystal of carbolic acid into the liquid the whole will become a solid mass within the space of perhaps three or four minutes.That is the method which Dr. Calvert constantly adopts in his works and it affords an instance in which there is not a mere question of a nucleus or of a solid body determining the formation of crystals. The vessel is far from being chemically clean the rods which the men use are far from being chemically clean and yet all this is of no use in causing the liquid to become solid; but just take the most minute quantity the size of a pin’s head and put it into a vessel where there is 5 cwt. of carbolic acid and in a moment it will be perfectly solid. The same may be done with acetic acid. You may take a jar of glacial acetic acid stir it move it shake it; but just put a crystal of glacial acetic acid into it and the whole vesselful whatever niay be its size will in five minutes be a solid mass.The President in calling upon Mr. Tomlinson to reply to the preceding observations wished to direct his attention par- ticularly-1. To the effect of different conditions of surface in the same body as in the platinized platinum of Smee’s battery this being a case in which porosity may be supposed to be con- cerned. 2. To the facilitation of the escape of vapour from boiling water by contact with paraffin or other greasy matter which appears to be similar to the case mentioned by Dr. Williamson inasmuch as we have there a vapour of a different kind into which the vapour of water can diffuse 150 TOiMLINSON ON CATHARISM itself incre readily than into its own vapaur.3. To the question whether these bodies which are called “dirty,” have really certain peculiar properties in themselves and whether if ae Dr. 0dling has supposed they were the containing vessel they would produce this evolution of gas or induce crystallisa- tion or whether it is not their presencein contact with another body-whether it is not the dm1 action-whether it is not the sides of the vessel haT-ing a certain amount of attraction for one part of the liquid and the unclean body for the other which produces a kind of rending action. Mr. Tomlinson replied in substance as follows :-With regard to the President’s observations upon the effect of char- coal in facilitating the evolution of gas this he could not attribute to the presence of gas in the pores of the char- coal because after charcoal has been made red-hot and then suddenly quenched under mercury or plunged into a boiling liquid it cannot be supposed to retain much air; but by its powerful capillarity it is always re-absorbing the liquid and under the continued action of heat giving it out again.The denser kinds of charcoal act most quickly hecause they sink to the bottom of the liquid and are thus brought nearer to the soiirce of heat. The platinized plates of Smee’s battery Mr. Tomlinson regards as very much in the condition of the plates employed by Davy exposing them to the air and gett-ing them oxidized. They collect particles of dust and get into an unclean condition and immediately there is a different adhesion between the gas of the cell and the liquid in the cell and thus there is an easy separation.Interior sides of vessela also are often in a condition of chemical impurity and it is this difference in adhesive force of a clean and an unclean surface which appears to constitute the whole matter. If t~ glass rod be exposed to the air or drawn through the hand or wiped with a cloth and then put into a solution,-say 9f soda-water,-it is instantly covered with gas bubbles; the reason of this appears to be that gas will adhere to ail oily greasy 01-fatty surface and water will not. But if the rod be freed from grease and then put into the soda-water the solution adheres to it as a whole and there is no separation because the adheBion is the same in both cases.With reference to the phenomena of ebullition alluded to by Dr. Williamson Mr. Foster and others Mr. Tomlinaon OR THE INFLUENCE OF CHEMICALLY CLEAN SURFACES. 151 expressed his opinion that the phenomenon of ebullition or generally the escape of gas or vapour from a liquid does not depend on the presence of air in the liquid. In connection with this subject he referred to two papers which he had published one in the 6‘Philosophical Magazine,” about two years ago the other in a recent number of the “Proceedings of the Royal Society,” in which the following experiments are described :-A wire cage made chemically clean was lowered int’o a glass of soda-water where there was a mass of air surrounded by the solution of carbonic acid and not a single bubble of gas escaped.But the moment the cage was rubbed between the hands and then put in it was covered with carbonic acid. So in the case of a boiling liquid. Several boiling liquids were tried. A wire-gauze cage was lowered so as to secure a mas8 of air in the centre or in the midst of a boiling liquid ; and one would suppose that if the air had anything to do with the liberation of vapour the vapour would have disdiarged itself through the meshes of the wire gauze into the cage; but so long a8 the cage was tho- roughly clean there was no such discharge of steam into the air. But a bit of paper or any solid let fall upon the cage instantly disengaged large quantities of vapour.From this and a large number of experiments of a similar nature Mr. Tomlinson infers that nuclei do not act by carrying tiown air and that air is not necessary to the ebullition of liquids. In Dufour’e experiment referred to by Professor Forjter Mr. Tomlinson considers that the water was in the spheroidal state. With regard to the sudden crystallisation of a salt or other substance from solution on dropping into the liquid a particle of the dissolved salt Xlr. Tomlinson concludes from his own observations that if the crystal be perfectly clean no such effect takes place ; it must be exposed to the air handled or otherwise rendered unclean before it will induce the crystal- lisation. NOTE. -In the discussion above reported several distin- guished chemists have objected to the term catharked or chernicaZ7y clean as not embracing all the phenomena.Now although by far the most commoii form of’ impurity is some kind of greasy matter which renders bodies unclean and there- fore active as nuclei while the absence of such fatty matter renders them cZem2 and therefore passive I am nevertheless TOMLINSON ON CATHARISM ETC. bound to admit that cases may arise i~iwhich the distinction between clean and unclean may not apply; aB when a solution of a solid in an oil is touched with a bit of ice both the s01u-tion and the ice may be cliemically cZean and yet the ice may act as a nucleus. So also a supersaturated aqueous solution cannot be kept as such in a vessel of stearin although such vessel be chemically clean.Stearin would act as a nucleus in mch a case. I have already (Phil. Trans. 1868) defined a nucleus as a body that has a stronger adhesion for the thing dissolved than for the liquid which dissolves it. This differential kind of action is not always expressed I admit by such terms as unclean and dean unless by an ex- tension of the meaning of such terms as are expressed in the words a-catl~arized and catharized:; but admitting the defkiition of a nucleus as just given to be correct the terms nucleixed and de-nucleizad would perhaps be sufficiently comprehensive to include all cases. Thus a glass rod which had been exposed to the air or drawn through the hand would be nzicleixed or simply a nucleus as respects aqueous and probably alcoholic solutions while a glass rod that had been washed in caustic alkali &c.would be de-nzccleixed or inactive as respects such solut'ions. The terms active and pawive do not quite accord with my view since the solutions exert a much stronger adhesive force on a so-called passive (clean) as compared with an active (unclean) rod. The principle I advocate is now on it'strial. If it be admitted a correct term will be found for it in the course of examination and further inquiry. I am indifferent as to the name because I am certain of the reality of the principle. The other objections that several gentlemen were so good as to bring forward will be of great assistance to me in enabling me to apply new tests to my work.I propose shortly to reply to them in a separate paper. C. T. Highgate N. 24th March 1869.

ISSN:0368-1769    

DOI:10.1039/JS8692200125

出版商:RSC    

年代:1869

数据来源: RSC

摘要:

153 X.-On the Butyl Compounds derived from the Butylic Alcohol of Fermentation. By ERNESTT. CHAPMANand MILESH. SMITH. (Read March 18th 1869.) C~RCUMSTANCES placed at our disposal a large quantity of fiisel oil,* from which a portion of the amylic alcohol had been removed. The crude oil just as it came from the distillers had been distilled and everything which came over in one dis- tillation below 1.27' collected apart. It was this portion boiling below 127' that we operated upon. It had been standing for a good many years in badly-corked jars and was conse-quently yellow and dirty. It was saturated with water. We operated on seventeen gallons of this material as follows -It was first simply distilled those portions which came over below 115' and those from 115' to 131' being col-lected apart.Everything which came over above 131' was also separately collected. That portion which came over at 115°-1310 was repeatedly distilled the distillation being stopped when the thermometer rose to 131' and that which remained behind being added to that which boiled above 131O. After this process had been repeated about ten times the greater portion of the liquid boiled between 106' and 115O or above 131'. That portion which boiled between 115' and 131' was now fractionally distilled in the ordinary manner. It almost entirely split up into liquids boiling above 13G' and liquids boiling below 115'. That fraction which oliginally boiled below 115' was now repeatedly distilled the distillate being always received in vessels containing fi-eshly-ignited carbonate of potash.This liqnid gradually split up into three fractions the one boiling about 130°,another boiling between 106O and 115' and the third boilingfrorn 79' up to 1013'. This latter fraction was gradually split up into bodies boiling above 106O and a considerable volume boiling below 80'; but large quan- tities remained which no amount of fractional distillation appeared capable of splitting into definite bodiea. As will be * From London Distilleries. VOL XXII. N 154 CHAPMAN AND SMITH ON THE BUTYL COMPOUNDS shown on a future occasion this portion which proved so un-manageable is of special iiiterest. The portion boiling between 106O and 115Owas now frac-tionally distilled.We are afraid to say exactly how many times but the fractionation took up several weeks. Finally we obtained from it about five litres of a body boiling within some &ths of a degree. This substance consists almost entirely of butylic alcohol. It is however contaminated with small quantities of iso-butylic alcohol. From this impurity it is im- possible to separate it by fractional distilliLtion notwithstanding the difference in their boiling points. NoTE.-The fractional distillations were performed in an apparatus like that sketched below. The distilling vessel consisted of a tin can,* such as is employed for holding methylnted spirit or varnish of two gallons capa-city ; it could distil conveniently between six and seven litres ; (e-)-_---* For the information of foreign readers we should perhaps remark that in Eogliah a tin can implies a vessel constructed of thin sheet iron coated with tin.It is known in Germany as *‘btech.” A small mistake in a foreign translation of one of our papers is the cause of the insertion of this note. DERITED FROM BUTYLIC ALCOHOL OF FERNENTATION. 155 its neck was closed by a cork through which passed a wide glass tube bent twice at an obtuse angle. C is the tin can used as a distilling vessel; a a is the tube; c is the connection with the condenser and d the thermometer. Of course great condensation takes place in this long tube and by slow distillation we may be assured of condensirig at least twice as much liquid in the tube as we allow to distil.This condensation very greatly facilitates the separation of the liquids by fractional distillation. The tube employed in most of these operations is about five feet in length about six-eighthe of an inch in internal diameter at the end connected with the distilling vessel and rather narrower-say about five-eighths of an inch-at the other end. It is made of very thin glass. We prefer it to a series of bulbs as recommended by Wurtz because it exposes a greater amount of surface in proportion to the vapour it contains. Moreover it mare readily drains is more easily cleaned and is less fragile. The disad- vantage of its inordinate length is to a great extent got over by bending it in the manner illustrated. Butyl compounds may be prepared from the above mixture of constant boiling point.We 'nave prepared and examined in detail the iodide bromide nitrate nitrite acetate alcohol and mercury compound. Iodide of Butyl is a heavy liquid agreeing accurately with TVurt z's description of it. It cannot be satisfactorily prepared by treating the crude butylic alcohol with iodine and phosphorus ; as under these circumstmces large volumes of butylene are evolved and a very poor yield is obtained. By operating with hydriodic acid this difficulty is entirely obviated. If the crude alcohol be mixed with a large excess of hydriodic acid of specific gravity about 1*85-1*9 and the mixtiire be raised to the boiling point the alcohol is without sensible loss converted into iodide. To prepare the iodide the crude alcohol is boiled for half an hour or forty minutes with four times its volume of hydriodic acid of specific gravity about 1.8 or rather higher.At the end of this period the alcohol is completely converted into iodide which latter will be found to have separated completely from the acid. It ig to be separated off and run into a flask containing carbonate of soda and water. The mixture of crude iodide and carbonate of soda solution is now distilled and the clear colour- N2 156 CHAPMAN AND SMITH ON THE BUTYL COMPOUXDS less iodide separated. It is then dried with chloride of calcium and fractionally didled; but by far the greater part of it is found to boil constantly at 121O. Small quantities of liquids of lower boiling point separate out.We prepared altogether about 1,300 grammes of the iodide. The fractional diBtillation was carried on in an apparatus like that previously described but consisting entirely of glass. The same remark applies to all other fractional distillations mentioned throughont t'his paper. Iodide of butyl is a clear colourless mobile liquid; it boils quite constantly at 121'. Its sp. gr. is 1,6301 at Oo 1.6032 at 16O 1.54816 at 50'; from which it follows that 10,000volumes at. 0' become 10,168.at 16O and 10,529 at 50'. The following decompositions of the iodide were observed :-With alcoholic solution of potash or ethylate of soda it is for the most part resolved into butylene and iodide of potassium or sodium a comparatively small portion only being converted into ethyl-bntyl ether.With alcoholic ammonia it is converted into butylaminea little or no butylene being produced. Heated with acetate of potash and glacial acetic acid it is converted into acetate of butyl; a certain amount of butylene is formed at the same time. Heated with bichloride of mercury it yields iodide of mer- cury aid chloride of butyl together with traces of hydrochloric acid and butylene. On heating it with zinc and ether large volumes of gas are evolved and a small quantity of zinc-butyl which however cannot be distilled out of the mixtnre. With dilute sodium-amalgam and acetic ether it yields mercury-butyl not, however without considerable evolution of gas. With cyanide of potassium it yields cyanide of butyl with tolerable facility and without the liberation of much butylene.With sodium it yields much gas consisting in part of buty- lene and in part of a gas which is in all probability hydride of butyl. The radical butyl is produced at the mme time but not apparently in any large quantity. As will be obvious from the foregoing this iodide possesses in a high degree the peculiar property of splitting up into hydriodic acid and olefine. Bromide of BxtyZ cannot be conveniently obtained by the DERIVED FROM BUTYLIC ALCOHOL OF FERMENTATION. 157 action of phosphorus and bromine on the alcohol ; partly because much butylene is eT-olved and partly because bromous substitution takes place to a very great extent. It is best obtained by saturating the alcohol with gaseous hydrobromic acid of which it readily absorbs rather less than ita own weight.This saturated liquid is to be mixed with its own volume of aqueous hydrobromic acid of sp. gr. about 1.6 or rather less ;the mixture is then to be heated in closed vessels up to the boilipg point of water.* The heating must be continued until the oily layer which separates out at the top no longer increases. When this is the case the digestion vessel must be removed from the hot water allowed to cool and opened. The bromide is then separated from the hydrobromic acid by means of the separating funnel. Should it contain phosphorus as it frequently does (hydro-bromic acid frequently having traces of phosphorus adhering to it) it is advisable to wash it with hydrobromic acid containing a little free bromine.So soon as it is slightly tinged with bromine it is run into a flask containing a dilute solution of carbonate of soda and distilled along with that liquid. The distillate is neutral and perfectly colourless ; the oily liquid is separated off from the small quantity of water which accom- panies it and dried over chloride of calcium. It is now frac- tionally distilled. By far the larger portion boils at 92* C. but another poi-tion which has apparently the composition of bromide of butyl boils 16O or 17" lower. Both liquids distil perfectly without decomposition and may be separated by fractional distillation though the process is somewhat tedious. Bromide of butyl is a colourless liquid of sp.gr. 1.2702 at 16'. Q We employed soda-water bottles closing them with corks nhich had been heated in melted spermaceti for half an hour before being used. Corks that have undergone this treatment are readily forced into the necks of the bottles though beforehand it was impossible to force them in at all. The corks were covered with little tin plates used by Messrs. Sandford and Blake in securing their soda-water bottles ;the corks were wired into the bottles the tin plates preventing the cork being cut by the wire. The soda-water bottles hold when full up to the neck between 2'70and 300 c.c. they will therefore take a charge of 200 C.C. conveniently. When charged and wired down they were placed in tepid water which was very gradually raised to boiling point.If the temperature be raised too rapidly the pressure becomes excessive and there is great danger of the bottles bursting. By raising the temperature gradually this danger appears to be entirely averted. At least in charging 15 soda-water bottles as above described not the slightest accident nor even the slightest leakage occurred. 158 CHAPNAN AND SMITH ON THE BUTYL comoms In its reactions it most closely resembles the iodide giVing of€ butylene in almost all decompositions. Its reaction with acetate of potash is dew and requires a tolerably high temperature. At 130° it takes many hours to complete the reaction but a little above this point it goes more rapidly. With sodium amalgam and acetic ether it behaves exactly as the iodide behaves.With ammonia the same remark applies. With cyanide of potassium decomposition is perhaps a trifle slower than with the iodide. With zinc its behaviour is exactly similar to that of the iodide. It does not appear to react with chloride of mercury. At any rate decomposition is very slow. With alcoholic potash it behaves exactly as the iodide does yielding butylene. We made about 1,600 grammes of the pure bromide boiling at 92OCy. A7itrate of ButyZ.-Nitrate of butyl is a colourless liquid of ~p.gr. 1-0384at Oo and 1.020 at 16'; it closely resembles the nitrate of amyl both in its stability and in its odour which resembles that of bugs-it boils at 123'. It has the most extremely disagreeable physiological action when in-haled causing restlessnese and most severe headache.It is prepared by a process strictly analogous to that by which nitrate of amyl was prepared by us. A mixture is made of two volumes of concentrated sulphuric acid and one of nitric acid of about 1.4 sp. gr. and 100 C.C. of this mixture are placed in a beaker surrounded by salt wat,er and ice. About 30 C.C. of the alcohol are now added fkom a small dropping funnel the stem of which is drawn off to a fine point and passes beneath the surface of the mixed acids; it is employed to stir the mixture as well as to add the alcohol. The alcohol must be added dowly and the mixture kept constantply stirred ; the nitrate rises to the surface as a clear colourless oil; it is decanted by means of the separating funnel and run into a retort containing excess of solution of carbonate of soda the process being repeated until a sufficient quantity of the nitrate has been prepared ;then the contents of the retort are distilled.The nitrate passea over quite unaltered along with the vapour of water. It is simply separated from the water and dried with chloride of calcium. If pure butylic alcohol has been wed DERNED FROM BUTYLIC ALCOHOL OF FERMEWTATION. 159 in its preparation it is now chemically pure; if not it must be fractionallj distilled when but 1it.tle difficulty ~vill be found in obtaining it of constant boiling point. Nitrate of butyl is unattacked in the cold by concentrated sulphuric acid; very strong aqueous potash has little or no action upon it ; alcoholic potash to a great extent resinifies it but at the same time a small quantity of ethyl-butyl ether appears to be formed :no trace of lnutylene is liberated and the action is exceedingly sluggish.The vaiioiis reactions which we have described in speaking of the nitrate of aniyl may all be repeated with the nitrate of butyl. It is converted into iodide of butyl with great facility when digested with strong hydlriodic acid binoxide of nitrogen and free iodide being liberated. Nitrite of Butt$.-Nitrite of butyl is obtained by passing nitrous acid into butylic alcohol; it is very desirable that the nitrous acid should be as free as possible from nitric acid. This may to a great extent be effected by never heating the mixture of arsenious acid and nitric acid excepting in the water-bat'h.Under these circumstances the nitrous acid comes over nearly pure and dry. The butylic alcohol must be kept cool by surrounding it with cold water and it is advisable to pass the nitrous acid into it slowly. When it is saturated the passage of nitrous acid must be discontinued and the nitrite thoroughly washed with water with dilute caustic potadi and then again with water. It will now present a brilliant bluish- peen colour of which it cannot be deprived by washing ;it may be dried over chloride of calciiim and fractionally distilled ;the distillate will be yellow. Great volumes of binoxide of nitrogen are evolved during the first portion of the distillation.Nitrite of butyl is a yellow light and very mobile liquid; its boiling point is difficult to determine with accuracy as it appears to undergo a slight decomposition. However its boiling point may be taken at 67O; at least on distilling 120 grammes of it it began to boil at a little over 65'; by the time 2 or 3 grammes had passed over it had arisen to 664O between which temperature and 67&O almost the whole of the remaining liquid distilled a very few grammes of liquid remained in the retort by the time the temperature had reached this point. This liquid is almost insoluble in water and ab- sorbs only the smallest traces of that liquid. It does not dis- solve chloride of calcium Its specific gravity is 089445at 0'; 160 CHAPMAN AND SMITH ON THE BUTYL COMPOUNDS -8771at 16'; and $25638 at 50'; therefore 10,000 volumes at Oo become 10,198 at 16' and 10,833 at 50'.It has the same physiological action that &rite of amyl has though the action is more intense. Its smell is not quite so disagreeable. In almost all its decompositions it closely resembles the before-mentioned nitrite of amyl-thus sodium liberates nitrogen from it ;slightly dilute sulphuric acid transforms it into butyrate of butyl With evolution of binoxide of nitrogen and sulphurous acid. Hydriodic acid converts it into iodide of butyl with liberation of binoxide of nitrogen and iodine. Ethylate of soda converts it in part into ethyl-butyl ether. The yield of nitrite of' butyl is not very good unless very great care be taken in its preparation as the butylic alcohol is easily oxidized into butyric aldehyd and butyiic acid which latter combines with a portion of the butylic alcohol to form butyrate of butyl.Of course the butyric aldehyd is removed during the mashing of the niti-ite and the butpate of butyl during the fiactional distillation ; 100 parts of butylic alcohol may however be made to yield from 105 to 110 of the nitrite. L4cetate of ButyZ is prepared by mixing crude butylic alcohol with glacial acetic acid saturating the mixture with hydro- chloric acid warming in the water-bath and then washing with cold water. The great bulk of the acetate separates at once; a small quantity however remains in the washings which are therefore distilled ; the distillate is treated with carbonate of potash; and the oily layer separated from the aqueous one.The oily layer is again treated with glacial acetic acid and hydrochloric acid and washed as before. The acetate so recovered is about 10 per cent. of the whole preparation. The mixture is now carefully dried fimt by agitation with carbonate of potash and subsequently by long standing over a new portion of the freshly ignited carbonate. It is now carefully fractionally distilled. Notwithstanding the drying the first portions of the distillate are always a little wet ; they are there- fore received in a flask containing more ignited carbonate. Other compounds of lower boiling point than the acetate separate fisom it during the distillation.Acetate of butyl boils at 117.5. Its sp. gr.is 089096at O' -8747 at 16' and 083143at 50'. Therefore 10,000 volumes at 00 become 10,186 at 16' and 10,716 at 50'. The smell of the acetate is fragrant only DERIVED FROM BUTYLIC ALCOHOL OF FERMENTATION. 161 distantly resembling that of acetate of amyl; it recalls the odour of quince. It is not easily decomposed by treatment with aqueous caustic potash. By sealing up however and so raising the temperature to 140' decomposition takes place very rapidly. With strong aqueous ammonia the ether is slowly decomposed into acetamide and butylic alcohol. With alcoholic potash it is decomposed almost instantaneously. With solution of pbtash in butylic alcohol the decomposition is eqiially rapid. Sodium dissolves in the acetate absolutely without evolution of gas.ButyEic Alcohol.-The pure alcohol is most readily obtained by decomposing the pure acetate with caustic soda. The acetate is poured upon about half its weight of powdered caustic soda. After a few minutes the mixture gets hot and finally boils violently. It should now be cooled by immersing the vessel containing it in cold water. The mixture will now have become a semi-solid mass. Water is now to be added and the whole distilled from the oil-bath. Butylic alcohol ac- companied by acetate of butpl and water distil orer. The distillate is now saturated with carbonate of potash the oily portion decanted and treated as before with caustic soda. In this second operation the conversion into the alcohol is quite complete.The mixture is now treated with water and again distilled from the oil-bath ; the distillate treated with carbonate of potash as before then thoroughly dried by boiling with and allowing to cool over carbonate of potash. It is next treated with a large quantity of caustic lime over which it must either be allowed to stand for gome weeks or else it must be digested along with the lime at a temperature between 65" and 75" for 12 or 14 hours. On now distilling it off the lime in the oil-bath it will be found to be perfectly dry. It boils at 1084O at the normal pressure going quite to dryness below 109". Its specific gravity is $055 at 16O.8. Its smell is quite different from that of the alcohol with a trace of moisture in it.Butylic alcohol cannot be dried by treatment with sodium. It would appear that hydrated oxide of sodium is more or less decomposed by butylic alcohol water and butylate of sodium being the products. At any rate butylic alcohol dried as per* fectly as possible with carbonate of potash was not rendered anhydrous by treatment with 6 per cent. of sodium. This 162 CHAPMAN AND SMITH ON THE BUTYL COMPOUNDS alcohol could not have contained much over 1per cent. of water 60 that there was much more than sufficient sodium to form even anhydrous oxide of sodium with the oxygen of all the water present. When quite dry butylic alcohol will dissolve about half an equivalent of sodium though only with considerable difficulty and with the aid of much agitating and heating.Butylic alcohol readily dissolves chloride of calcium acetate of potash and caustic potash. It does not appear to dissolve notable quantities of the chlorides nitrates or sulpliates of the alkalies. It does not dissolve cyanide of potassium. It is readily mis-cible with glacial acetic acid also with glacial acetic acid to which twice its volume of water has been added It is very readily soluble in hydrochloric acid. It dissolves in about 11 volumes of water. If large volumes of the alcohol be distilled it is possible to obtain a portion of it nearly if not quite an- hydrous. The best plan of drying really large volumes of the alcohol appears to be to distil it repeatedly always treating the first portion of the distillate with carbonate of potash.The alcohol appears to form a definite hydrate which however cannot exist at the boiling point of water. Treatedwith iodide of phosphorus or iodine and phosphorus the alcohol is con-verted partially into butylenc and partially into iodide of butyl. We have never been able to obtain a conversion of' more than 60 per cent. of the alcohol into the iodide. With bromine and phosphorus a perfectly similar decomposition takes place. If the alcohol be cooled to -15" or -16" C. and then poured slowly into concentrated sulphui-ic acid kept at the same low temperature the alcohol appears to be totally or almost totally converted into butyl-sulphuric acid. If the mixture be effected at the ordinary temperature polymerised butylenc appears to be the piincipal product.If the sulphuiic acid be diluted with a third of its weight of water and the mixture gradually effected at the common temperature but$-sulphuric acid is the principal product. If butyl-sulphuric acid be diluted and gently warmed and excess of crystaked sulphate of soda added a colourless liquid of most extraordinary odour rises to the sur- face. This liquid is soluble in water in all proportions. It appears to be a hydrate of butylic alcohol. At any rate on distillation it splits up into water and butylic alcohol. Mercury-ButyZ.-Mercirry-~utyl is eaaily prepared by the DERIVED FROM BUTYLIC ALCOHOL OF FERMENTATION. 163 general method given by Frankland and Duppa for the pre-paration of the mercury-compounds of the alcohol radicala.Five granimes of sodium were dissolved in over 2,000 grammes of mercury and agitated with an equivalent quantity of iodide of butyl to which about one-tenth of its weight of acetic ether had been added. The process was carried on in a stout glass- stoppered bottle the stopper of which was removed and its place supplied by a bored cork carrying a long wide upright. glass tube; this served as a condenser. When the mixture in the bottle was vigorously shaken the mercury which at first remained fluid soon divided itself into an infinite number of minute globules which with the liquid and iodide of sodium formed a grey pasty mass in which after a while not a single globule of mercury could be discovered.On further agitating the mixture as the reaction slackened the mercury coalesced again into a liquid mass. Great heatwas given out during the reaction. When the bottle was nearly cold it was found that the mercury could be poured out in a perfectly clean state with- out the smallest difficulty the whole of tht mercury-butyl iodide of butyl &c. remaining in the form of a paste along tVit,h the iodide of sodium formed and a small quantity of mercury. The mercury was at once re-amalgamated poured into a clean bottle and again treated with iodide of buts1 and acetic ether a8 before. During the progress of the second operation the first bottle was washed out the washings being collected in a retort ; this bottle was nciw dried and was ready to receive the charge of mercury from the other bottle by the time the operation going on in it was completed.The process was continued in this way until a sufficient quantity of crude mercury-butyl had been obtained. The contents of the receiving retort consisted of two layera an aqueous layer and a layer of dense liquid at the bottom. Most of the water in the retort was removed and the contents of the retort were distilled from the oil-bath. Mercury-butyl passes over readily with the vapour of water. The distiIlate consisted of two very well-defined layers the lower being mercury-butyl contaminated with iodide of butyl and acetic ether. To fi*eeit from these two latter impurities it was placed in small retorts and a current of steam driven through it ; this was continued until no iodine could be detected in the distillate.The liquid in the retort was now separated from the water accompanying it and dried with chloride of calcium. 164 CHAPMAN AND SMITH ON THE BUTYL COMPOUNDS Mercury-butyl thus prepared is a colourless tramparent liquid of sp. gr. 1*7469 at O" and 1.7192 at 16". It cannot be distilled by itself but it will stand a temperature of 130" without undergoing much decomposition. It combines with iodine and bromine with characteristic violence. Boiled with hydrochloric acid it liberates a gas apparently hydride of butyl. It is attacked with comparative facility by zinc forming zinc-butyl; no great disengagement of gas takes place in the transference. It has the peculiar disagreeable yet perfume-like smell which appears to be characteristic of the whole of this class of bodies but we did not experience the slightest ill effects from working with it.Its smell is one the dislike to which is soon converted into absolute disgust. We are not acquainted with any sub- stance excepting these mercury-radicals the smell of which we cannot more or less accustom ourselves to; but though at first the smell does not strike one as being peculiarly disagree- able after a few days' work we seemed instinctively to shrink from it ; we have prepared all the known mercury-compounds of the alcohol radicals and have always found that they pro- duce this extreme disgust. We may here observe that we do not think that there is any great danger in working with these compounds now that their poisonous nature is 60 well esta- blished.The butyl spoken of in the above paper is isopropyl- rn e thy 1;the alcohol therefore would be in K o1 b e's nomen- clature isopropyl carbinol and is represented by the for- mula-(OH The alcohol yields on oxidation iso-butyric acid. We defer a detailed account of' its oxidation products to a future com- munication. The following is a tabular statement of the boiling-points and specific gravities of those butyl-compounds examined both by W iir t z and ourselves. With regard to the specific gravity of the iodide we have here inaerted a specific gravity observed at19" so that the humbers may be strictly comparable. It will be Been that whilst DERIVED FROM BUTYLIC ALCOHOL OR' FERMXNTATION.165 the iodide and alcohol agree closely as to boiling-point alI the other compounds differ notably. -4s we have made many pre- parations of all these compounds and have operated on a very large scale we think the numbers we give may be implicitly depended upon :-Boiling point Co. Specific gravity. Name of substance. c.& 5. Wurtz. c. & 5. I Iodide of butyl.. ...... Bromide of ditto.. .... 121 89 121 92 1.604 at 19 C. 1.274 at 16" C. 1 .59C3 at 19"C. I -2702 at 16OC. Nitrate of ditto ..,,,. Acetate of ditto ...... Butylic alcohol. ....... 130 114 109 123 117.5 ioa-5 heavier than water ,8845 at 16"C. *8032at 18*5" C 1 *030at 16"C. -8747 at 18" C. -804at 18PC. ~ APPENDIX Containing the evidence on which the above account of the butyl-compounds rests.A. The following is the proof on which we base our assertion that we are dealing with butyl-compounds First. A combustion of the alcohol. Burnt with chromate of lead. 03507 grammes of the alcohol yielded 4348 grammes of carbonic acid and 440 grammes of water from which the follow- iiig percentages of carbon and hydrogen are calculated :-Theory. C ................ 64-92 64.8'7 H, .............. 13.94 18-51 O................ 21.62 Second. A combustion of the iodide obtained fiom the alcohol was made. Burnt with chromate of lead and copper-turnings 0844 grammes of the iodide yielded -807grammes of carbonic acid and 03775 of water. These iodine determinations were made in three different samples of the iodide prepared at dif-ferent times.I. 1.257 grammes of the iodide yielded 1.6016 of iodide of silver. 11. -6904 of iodide yielded -8839 of iodide of silverd 111. *8830 of iodide yielded 1.1253 of iodide of silver I66 CHAPMAN AND SMITH ON THE BUTYL COMPOUNDS From the above the following percentages are calculated :-I. 11. 111. c c ............ 26.08 - L -H ............ 4.97 - I ............ -6S*86 69-19 68-87 Theory. Found. C4........ 48 2 6.09 2 6.08 H9.. ...... 9 4.89 4.97 I ........ 127 69-02 68-91 (mean) 184 100. 100.02 These iodine determinations were made by decomposing the iodide with alcoholic soda free fieom chlorine (obtained by dis- solving sodium in alcohol).The alkaline iodide was rendered acid by dilute nitric acid and precipitated with nitrate of silver. The iodide of Eutyl was also titrated in the manner described by Professor Watnklyn the digestion being carried on in sealed tubes. I. 2,471 gramrnes of iodide digested with alcoholic soda neutralized as much alkali as 13.5 C.C. standard sulphuric acid would have done. 11. 5.384 grammes of iodide neutralized soda equivalent to 29.3 C.C. of standard acid. These titrations correspond to the following percentages of iodine :-I. 69.38 11. 69.11 Theory 69.02. When we recollect that the atomic weights of propyl butyl and amyl are as follows C,H =43 C,H9 = 57 and C,Hll =71 we see that a determination of the atomic weight at once points out with which radical we are dealing.Now the atomic weights as deduced from the three iodine determinations are respec- tively :-I. 57043; 11. 56.55; 111. 57.4. The atomic weights deduced &om the titrations are- I. 56.05; 11. 56.76. The above appears to us to be ample and more than ample proof that we were dealing with butyl compounds ;incidentally it establishes also the purity of the alcohol and the iodide. B. Proof of Pudy of the Iodide of ButyL-This depends lst DERlVED FROM BUTYLIC ALCOHOL OF FERMENTATION. 167 on the combustion given above; 2nd on the three iodine determinations given above ; 3rd on the two titrations given above; 4th on the yield of iodide from the alcohol. 80 grammes of the alcohol were digested with a very large excess (500 cc.) of hydriodic acid of apecific gravity 1.8 for forty minutes.The mixture was then distilled the distillate rendered alkaline with carbonate of soda and again distilled. The heavy oily layer of the distillate was pipetted off and while still wet weighed. Weight 198.5 grammes. To ascertain how much water hung about it 200 grammes of the pure dry iodide were distilled from carbonate of soda solution and the distil- late weighed &c. as before; it now weighed between 201.5 and 201.6. We may therefore assume that the increase of weight due to moisture was about 1-5; this gives us 197 grammes as the yield of iodide from 80 grammes of alcohol therefore-100 parts of alcohol yield 246.25 parts of iodide. 100 parts of butylic alcohol yield 248.65 parts (theoretically.) 100 parts of propylic alcohol yield 383.33 parts (theoretically.) 100 parts of amylic alcohol yield 225 parts of iodide (theo- retically.) We have therefore obtained 99-03 per cent.of the yield of iodide theoretically obtainable from butylic alcohol. C. Proof of purity of Bromide of ButyL-This rests entirely on the yield under the circumstances a perfectly sufficient datum. Two experiments were made on 80 grammes of the alcohol. I. yielded 147.4 grammes of bromide; 11. yielded 146.7 grammes ; or calculating from these yields- By I. 100 parts of alcohol yield 184-25 of bromide. 9 9, ? 11.9 ,) 183-38 , Theoretically , , 185.14 of bromide of butyl. We have therefore obtained reBpectively- I. 99-52 per cent.; II.99.05 per cent. of the theoretical yield. The conversion of the alcohol into the bromide was effected in soda-water bottles. The weighing of the bromide was in this instance effected dry; the contents of the soda-water bottles were distilled the distillate re-distilled from carbonate of soda solution the oily layer pipetted 0% and dried over chloride of calcium; it was now decanted from the chloride of calcium and weighed. Water was now added to the chloride of calcium and the mixture distilled whereby a few grammes 168 CHAPXAN AND SMITH ON THE BUTTL COMPOUNDS of bromide were recovered ; these were decanted and weighed wet and their weight added to the weight of the dry bromided As in neither case did the weight of this wet portion amount to 4 grammes and as bromide of butyl does not contain more than 97 per cent,.of water the error introduced by weighing this bromide wet could never amount to 0-03 grammes a quantity totally without influence on the result and indeed only influ- encing a figure in the third or fourth decimal place. D. Proof of purity of Nitrate of ButyL-This depends also on the yield. From the nature of the method of preparation a very sharp result could not be expected. Two determinations were made :-I. SO grammes of the alcohol yielded 126.5 grammes of the nitrate. 11. 100 grammes of the alcohol yielded 158.5 grammes of the nitrate. Calculating fiom I. 100 parts of the alcohol yield 158.13 of the nitrate; and by II. 100 parts of the alcohol yield 158.5 of the nitrate.Theoretically 100 parts should yield 160-8. From I. therefore we have obtained 98.35 per cent. of the theo- retical quantity and from IT. 98.57 per cent. E. Proof of purity of Acetate of ButyZ.-In this case we could not depend upon the yield because it is necessary to wash the acetate many times and because it is difficult to ensure the total convergion of the alcohol into the acetate. Still by dis-tilling the washings and treating the mixture of acetate and alcohol obtained from them with glacial acetic and gaseous hydrochloric acids and again separating the acetate so obtained we succeeded in obtaining between 96 and 97 per cent. of the theoretical yield. The proof of the purity of the acetate how-ever rests on titrations of which two were made.I. 3-9246 grammes of acetate neutralized as much caustic potash as 42.2 C.C.of standard acid could have done. 11. 4-9846 grammes neutralized as much potash a8 53.7 C.C. standard acid; of this acid 1 C.C. equals 0*03118 grammes of potasaium. From these numbers we calculate that according to-I. It yields 51.44 per cent. of acetic acid; and according to II. 51.53. Theoretically it should yield 51.72. F. Proof of purity of Mercury Butyl.-This rests on a deter- mination of the mercury contained in the compound. DERIVED FROM BUTYLIC ALCOHOL OF FERMENTATION. 169 0.370 of the compound yielded 0.235 of metallic mercury therefore 63-51 per cent. Theory for (C H9),Hg requires 63.69 ,) G. Proof of purity of Butylic AZcohoL-This rests first on the combustion quoted above; secondly on the yields of iodide bromide and nitrate ;lastly on the purity of the numerous butyl compounds obtained from it as shown by the iodine determina- tions and other analyses quoted above.H. The annexed table contains the equivalent of but71 deduced from the various analyses mentioned above. It is appended chiefly because in this manner and in this manner only can the exact comparative value of the different estima- tions be seen since the intervals between the percentage composition of different compounds vary so greatly that what is a sufficient approximation to the trut8h in one case has com- paratively little meaning in another ; thus in comparing one combustion with another for example a combustion of butylic alcohol with one of iodide of butyl an error of 0.25 per cent.in the carbon in the case of the alcohol would only correspond to an error of 0.1 per cent. of carbon in the iodide. If there- fore we were to argue from two combustions one of the alcohol with an error of -5 per cent. and one of the iodide with an error of -25 per cent. we should arrive at a more accurate result by using that combustion with the largest appa.rent error. TABLEshowing the Atomic Weight of Butyl as deduced from the following 13 determinations. Atomic weights deduced from. Nature of Determination. 3ets of Expe-solatedExpe-riments and riments. neam of sets. (1.) By combustion of alcohol C + H found = 79.86 per cent.100 -(C + H) found 22 14. 2214 79.86 : 16 = (Eq 0) atomic weight.. .... .. 66 *27 (2.) Bycombuebion of iodide C + H found = 31-05 per cenf. 100 -31.05 per cent. = 68-95 :. 68.95 31.6 : 127 = (Eq I) ....,.....,,.................q .. 67 .I9 VOL. XXH 0 170 CHAPMAN AM3 SMITH ON THE BUTYL UOMPOUNDS Atomic weights deduced from. Nature of Determination Sets of Expe-solated Expe- riments and riments. neana of seta By estimation of iodine in iodide as Ag I-(3.) 1. ......................................... 57 *43 (4.) If. ........................................ 56.55 (5.) 111.. ....................................... 57 -40 Mean.. ...................................... .. 67 -13 By estimation of iodine in iodide by titration- (6.) I......................................... 66-05 (7.) 11. ........................................ 56 *76 Mean. ....................................... .. 56 -41 (8.) By yield of iodide of butyl from alcohol ........ .. 58 -22~ By yield of bromide-(9.) I. . ...................................... 67 *77 (10.) 11. ....................................... 58 *50 Mean.. ...................................... .. ti8 -17 By titration of aeehte-(21.) I. ........................................ 6'1 -64 (12.) IT. ....................................... 67*42 Mean.. ...................................... .. 67 *63 (13.) By estimation of Hg in mercury butyl. ........ .. 67-46 Mean of all determinations ...................... 67.30 DISCUSSION. Dr. Odling objected to the definitions commonly given especially in text-books of primary secondary and tertiary alcohols these definitions being based upon the manner in which the carbon atoms are supposed to be grouped whereas it would be much better that they should be founded upon reactions. The definition of a body should in fact be that it is one which behaves in a particular way from which its constitution is after-wards inferred. Thus with regard to the particular case under consideration an alcohol may be classed as primary when it * We should perhaps here point out that the method of exhibiting the resuIts o€ analysis in atomic weights whilst it shows the relative value of anaiyses better than any other plan exaggerates the apparent error very much.Thuu for example if we exhibit the percentage composition of iodide of butyl 88 detetmined by the yield we obtain 68-57 per cent. of iodine a result which is-&G bf the iodine in Prror' but the atomicz weight is 58-22 a result fiin error. DERIVED FROM BUTYLfC ALCOHOL OF FERMENTATION. 171 yields by oxidation an acid containing the same number of carbon atoms. Hydrocarbons may be formulated first according to the residues which they contain viz. :-Methyl.. ............ CH,’. Methylene .......... CH,”. Formyl ............ CH“‘. Carbon ............ C””. Secondly according to the number of each of these constituent residues; and thirdly according to the manner in which they are tied together.The hydrocarbon C4H1,, from which the butylic alcohol under consideration is derived is admitted to contain the residue CH three times its formula being CH(CH,), and the piimary alcohol derived from it by substitution of OH for €3. in one of the groups CH will be-CH CH, r3 CH,OH. Such formulae have this advantage over those now generally in use that they do not involve any particular assumptions as to the superiority in importance of one hydrocarbon residue over another and its consequent selection for the post of honour as the typical basis of the formula. Professor W ankl y n said that the classification of alcohols according to the linking of the carbon atoms appeared to him to be indirectly a classification according to reactions but that he preferred to classify according to the linking and to have criteria by which to recognize that linking.The butyl alcohol which forms the subject of Mr. Chapman’s paper is a primary alcohol that is an alcohol in which the carbon which is united with hydroxyl is united directly with only one atom of carbon. The criterion by which we recognize such an alcohol is that by oxidation it gives an acid containing the same number of atoms of carbon as the alcohol itself. The alcohol that Mr. Chapman haa examined fulfils this character. By oxidation it gives isobutyric acid which has the same number of atoms of carbon as the alcohol. In order to get this isobutyric acid we have to oxidize carefully but still we can get an acid containing the 02 172 CHAPMAN AND SMITH ON THE BUTYL COMPOUNDS same number of atoms of carbon as the alcohol.This alcohol would be called a pseudo-primary or an iso-primary alcohol. The proof that this alcohol is not the normal butylic alcohol c{r ,is that the four-carbon acid formed from it by oxidation is not common butyric acid C 0 ,but iso-{F2cH3 butyric acid C 0 ,identical with that which is produced r3), by the action of alkalies on cyanide of isopropyl. The salts of these two acids exhibit considerable diversities of character. The calcium salt of isobutyric acid is much more soluble than ordinary butyrate of calcium and isobutyiic ether boils at 112" whereas butyric ether boik at 119'. Mr. Chapman observed that a further difference between these two iaomeric acids is afforded by the fact that isobutyric acid breaks up on oxidation whereas normal butyric acid does not.Dr. Odling said that it wa8 not the ordinary mode of classi- fshg the alcohols that he objected to but the definitions. He thought as a matter of logic that the definition should have reference as nearly as possible to the criteria or characteristic properties of bodies 80 that in saying that a Body belongs to a particular class we should be understood as implying that it behaves in a particular way. Dr. Crum Brown said that he perfectly agreed with the last remarks that had fallen from Dr. Odling though he could not quite agree with him respecting the classification of the alco- hols. Some alcohols when oxidized yield an aldehyde and mme aldehydes (those namely to which the term is generally applied) yield by oxidation acids containing the same number of carbon atoms.NOW the alcohols which yield aldehydes converted by oxidation into the corresponding acids are those which we call primary alcohole. Then again there are alcohols convertible by oxidation into aldehydes (ketones) which when subjected to the action of oxidizing agents split up into two acids; theRe are the secondary alcohols. And lastly there are alcohols which do not yield aldehydes at all but split up at once by oxidation into acida containing smaller num- DERIVED FROM BUTYLIC ALCOHOL OF FERNENTATION. 173 bers of carbon atoms. So far as we can at present Bee &om observed facts primary aecoudary or tertiary alcohol is a carbinol in which 1 2 or 3 atoms of hydrogen are replaced by alcohol radicals.By classifjTing in this way we get rid of the danger attending the too free use of the atomicity theory which must be regaded as at best only a temporary expedient destined Booner or later to be replaced by a theory more in accordance with the true principles of physics. Theories in fact are but mere scaffolding; let them be used as such and knocked away when the proper time comes. Dr. Guthrie inquired what was the precise origin of the fusel oil upon which Mr. Chapman had been working. It would be interesting to know whether it was obtained fiom potatoe spirit or grain spirit. Mr. Chapman expressed his regret at not being able to give an exact answer to the question and indeed he thought it would be difficult to obtain a precise answer as many distillers are in the habit of using mixed grtius.The fusel oil upon which he had worked was obtained fiom Bowerbank‘s and fiom Whatney’s and unfortunately the two had been mixed before he got them. He had however examined many other specimens of fusel oil and they all appeared to contain butylic alcohol. Returning to the question of formulae and classification Mr. Chapman said ‘‘1 do not see any objection to the mode of defining the several claases of alcohols proposed by Dr. Odling and Dr. Crum Brown which indeed is quite in accordance with observed facts. There is however one car- dinal point about alcohols or the compounds derived fiom them.Some alcohols split up directly into olefine and water and some do not. Now can we not base some kind of classification upon this fact or can we not make it a portion of some classi- fication? I of courae have never seen tvha,t would be called normal primary butylic alcohol. But if it should turn out that on treating normal iodide of butyl with alcoholic potash no butylene whatsoever is evolved and that on treating this isopropyl car- binol with alcoholic potash butylene is evolved as we know it is I think we should there have a very fair ground for beginning to make a very wide division of the alcohols and that we should perhaps be justified in calling one set of them hydrates of olefines and another alcohols giving them two generic names.There 174 STOKES ON A CERTAIN REACTION OF QUININE. is however another question not immediately connected with this. Before we can argue very directly as Dr. Odling and Dr. Crum Brown appear to wish from the reaction to the nomenclature we must have a very much more careful study of the reactions than has hitherto been made. At the prerJent moment we do not know whether on treating iodide of amyl with alcoholic potash any amylene is evolved or not or whether ontreating common iodide of ethylwith alcoholic potash anyethy-lene is evolved. I have however ascertained that on treating normal bromide of proyyl which I have obtained from another portion of this fusel-oil with alcoholic potash no olefine or only an infinitesimal quantity is evolved.”

ISSN:0368-1769    

DOI:10.1039/JS8692200153

出版商:RSC    

年代:1869

数据来源: RSC