摘要:

THE QUARTERLY JOURNAL OF THE CHEMICAL SOCIETY June 3 1850. THOMAS GBAHARf EsQ.,Yap.,in the Chair. Dr. D. S. Price was elected a Fellow of the Society. The following presents were announced ‘‘The Pharmaceutical Journal for June :” from the Editor. Journal of the Franklin Institute for March and April :” from the Institute. “Watson’s Chemical Essays :” from Nr. Medlock. The following papers were read XX.-Analysis of the Ashes of the Spanish Potato ~~onvo~v~l~~ Batatas) and of the Eddoes (Arzcm esculenturn Linn. Colocnsia esculenta Schott,) BY THORNTON F.C.S. J. HERAPATH The Spanish or sweet potato and eddoes although of little or no importance to the English agriculturist are conimonly cultivated for their roots in most if not in all tropical climates both in the eastern and western hemispheres.The tubers of these plants in fact are employed in large quantities in all the West Indian Islands as food for man and animals and are looked upon in those countries as is the potato in our own being at the same time nutritious and pleasant to the $taste Only the roots of the former the batata however I am informed can be made use of by Europeans those of the latter particularly when fresh being extremely acrid although not so much so as to render them unpalatable to the negroes with whom they are a common article of food. This acrimony would appear to be caused by the presence of some volatile body as the VOL. 111,-NO xr. 0 MR. HERAPATH ON THE ASHES vegetable is said to become sweet and well-tasted after boiling or when roasted in hot ashes Proximate analyses of these plants have been already performed by other chemists,* but no attempt as fm as I am aware has ever beell made to determine the nature of their inorganic constituents.It was therefore with the wish of supplying this desideratuln that I undertook the present examination as I thought my results might possibly be of service to some of those of my fellow-countrymen who are connected with the interests of our West Indian colonies. For the specimens which I have operated upon I am indebtcd to the kindness of my friends Charles Thornton Coathupe Esq. of wraxall and W. H. Richards Esq. of Barbadoes to both of whom I must acknowledge my obligations.The modus operand; employed in the preparation and analysis of these ashes has been already fully explained in some of my former papers which have been communicated to the Society. I.-SPANISH POTATO OR BATATA. 749.54 grs. of the fresh roots cut into thin slices gave 249.34 grs. of dried vegetable matter and furnished upon incineration 11.996 grs. of ash. Subsequent analysis however proved that this ash contained 0.690 grs. of charcoal and sand; consequently the true inorganic coastitueiits amounted to 11.306 grs. in weight = 1.50849 per cent numbers which correspond to Water and other volatile matters . 66.7340 Vegetable matter . . 31.7575 Inorganic constituents . . 15085 100~000 The proportion per cent of ash from the dried plant therefore amounted to 4,5347.The 11.996 grs. of ash obtained as above xere found up011 analysis to be composed of Substances soluble in water (A) * 7.883 , insoluble , (B) 4*113 The solution A when treated with re-agents gave 8 Carbonic acid . . 0*9800 SuIphate of baryta . . 2*37OO=SO 0.8030 * 0.Henry J. Pham. [3] XI 233. OF THE BATATA AND THE EDDOES. Phosphate of baryta (3 BaO. PO,) 0*45OO=PO 0.1058 Chloride of silver . . 5°7600=C1 1°4400 Mixed chlorides of potassium and sodium . . 8.0770 Potassio-chloride of platinum. 22*056= KCI 6.7897= KO 4.2786 Chloride of sodium (by loss) f*2873=NaO 0.6868 Quantities which are equivalent to Carbonate of potash . 3.118 = 27.5763 p. c of ash.Sulphate of potash . . 1.766 = 15.6243 , , Phosphate of potash (3 KO. PO,) ' . . 0.302 = 2.6771 , , Chloride of potassium . 1.407 = 12.4465 , , Chloride of sodium . . 1.287 = 11.3904 ,, -79380 = 69.7146 The substances insoluble in water (B) furnished Carbonic acid 8 0.7040 Sulphate of baryta . traces SO . traces Earthy phosphates &c. 1.626 . 0.1988 Perphosphate of iron . 0'346= {g:O . 0.1472 Phosphate of alumina # traces Pyrophosphate of magnesia. 1*335= PO . 0*8009 Carbonate of lime . 2*449= CaO . 1.3719 Pyrophosphate of magnesia. 0*404= MgO 0.1613 Silica . . . . * . . 0*2400 8 Charcoal sand &c. . 0.6870 They were consequently composed of Carbonate of lime . 1.334 = 11,7970 p.C. of ash. Carbonate of magnesia. 0.224 = 1.9828 >) , Sulphate of lime. . traces = traces ,) Perphosphate of iron 0.346 = 3.0595 , )) Phosphate of alumina . traces = traces , , Phosphate of lime (3CaO. PO,) . . 1.160 = 10.2590 , , Phosphate of magnesia. 0.120 = 1.0613 ) ,J (. Silica . . Q240 =1 2.1258 yJ Charcoal sand,and IQSS 0.689 = deducted - 4.1113 = 30.2854 02 MR. HERAPATH ON THE ASHES The percentage-composition of the ash of this plant after deduc- tion of the charcoal sand and carbonic acid may be expressed as follows SOLUBLE SALTS co . . 8.6671 After deducting the CO,. so . . . 7.1018 8.3448 PO . . 0.9357 1.0324 KO . . . 29.3490 34.4848 NaO * . -0-KC1 . . . 12.4465 145070 NaCl .. . 11.3904 13.3848 INSOLUBLE SALTS co * . 6-2289 PO so 0 . . 7.0720 . traces traces 8.3769 CaO . . . 11.9545 14.25 43 MgO Fe 0 . . . . . 1.4265 1.3018 1.6761 1.5297 M,O . . traces traces SiO . . 2.1258 2.4092 100*0000 100~0000 11,-EDDOESOR EDDOW. 74918 grs. of the fresh root when dried and incineratcd fur- nished 12.729 grs. of ash which was afterwards found to contain 0.39 grs of carbon and sand; consequently the true weight of ash was equal to 12.339 grs. = 1.6470 per cent. These 12.729 grs. of ash when treated with hot water were resolved into Substances soluble in water (A) . . . . 7.854 , insoluble , (B) . . . 4875 The aqueous solution (A) when treated in the usual manner afforded of Carbonic acid .. . 1.2820 Sulphate of baryta. 1-18?'= SO . . . . 04025 Phosphate of baryta (3Ba0.P05) . 2*147== PO . . 05090 Chloride of silver 2.070 = C1 . 0,5175 a Mixed chlorides of potas-sium and sodium 8.460 OF TEIE BATATA AND THE EDDOES. 197 Potassio-chloride of platinum 23.376 = RC1= 7.597 = KO 4.7981 Chloride of sodium (by loss) . . 0,863 = NaO 0.4603 Quantities of which are equivalent to Carbonate of potash . . . . 4,0791 = 33.0532p. c. of ash. Sulphate of potash . . . 0.8855 = 7.1'752 , , Phosphate of potash (tribasic) 2.0270 = 26.4249 , , Chloride of sodium . . . . 0.8630 = 6.9929 , , The substances insoluble in water (B) gave upon analysis Carbonic acid . . . . . . . . . . . 0.4430 Sulphate of baryta .0.399 = SO . . 0.1353 Earthy phosphates &c. 2.616 PO . . . 0.1089 Perphosphate of iron . 0.230 . (Fe o . o.1211 I Phosphate of alumina . traces Pyrophosphateofmagnesia 1.837 Carbonate of lime . . 3.467 Pyrophosphateof magnesia traces Silica . . . . . 0.633 Charcoal and sand . . 0.390 They were therefore composed of Carbonate of lime . . . . Carbonate of magnesia . . Sulphate of lime . . . Perphosphate of iron . Phosphate of alumina . Phosphate of lime (tribasic) Phosphate of magnesia . . Silica . . . . . * Charcoal and sand * . . = PO . . . 1.1023 = CaO . . . 1,9421 == MgO . traces 1*0070= traces = 0.2300 = 0.2300 = traces = 2.3860 = traces = 0.6320 == 0.3900 = 8.1590 p.c. of ash. traces ,) 19 3.8637 , ,? 1*8637 , $3 traces. 18.2223 , J traces. 5.2451 , deducted > L 4.8750 35.3538 After deducting the carbon and sand and carbonic acid the com- position of the ash of the eddoes may therefore be stated as follows SOLUBLE SALTS CO . . . . . SO . . PO . . . . KO . . . . . NaO . . . . . KCl . . . . . NaC1. . . . . 10.3921 . After deducting CO 3.2614 . . . 4.0920 . . . . 38*8790 . . . L_ .... I .... 6.9929 . . . -63,6174 3.7879 4*7526 45.1440' c_ c 8*1218 53.8063 MR HERAPATH ON THE ASHES 198 Soluble salts . . 63*6174 + b 53.8063 INSOLUBLE SALTS 3.5086 -0 m...co . . so3 b 1.0963 . . . 1.2732 .me.. PO *...* 9.8144 . . . . 11.3990 15.7369 . . . . 18.2774 CaO . . . traces . . traces MgO. . 0.9813 . . . . 1.1397 Pe,03 . traces . . . traces A&O * . . SiO . . . . . 5.2451 . . . . 6.1044 * 100*0000 1oo*oooo Now if we compare the results of the two analyses just recorded with those of my former examination of potato-ashes,* we shall observe a very close resemblance between them; in fact the ashes of all these three plants evidently belong to the same class namely to that in which the alkaline carbonates predominate. Reasoning from this circumstance alone then we should be led to expect that the same species of soil would be suitable for the cultivation both of the potato eddoes and batata; and such I am informed is the fact.The ashes of the potato however we shall find contain a much larger proportion of alkalis and phosphoric acid than either of the others; and we should hence at first be induced to believe that the former plant would prove a more exhausting crop than the eddoes or batata; but 8 little calculation will show us that this would be an erroneous conclusion; in fact just the opposite is the case as Will be readily seen upon consulting the following table TABLEI. Showing the amounts of the several inorganic consti- tuents removed from the soil in a ton weight of each crop Batata. Eddoes. Potato.$ ~~ -Sulphuric acid . . . 2 lbs. 6 oz. 1 lb. 13 OZ. 1 lb. 24 ox.Phosphoric acid . . 2 11; 5 1 3 74 Potash . . ' . . 9 144 14 2$ 13 9 Chloride of potassium. 4 22 --.__ Chloride of sodium 3 13% 2 2 0 1; Lime. . . . . .4 1+ 5 15 0 114 Magnesia . . . . 0 7g a little 0 15 Oxide of iron . . . 0 7 0 52 Silica . . . . . 0 11% 1 144 281bs. 15oz. 31 lbs. 59 ox. 19lbs. l4g ox. * Chem. SOC. Qu. J. 11 21. t This cdculation was made by taking the mean of the five analyses given in the paper just referred to -.-,---. OF TEE BATATA AND THE EDDOES TABLE11. Giving formule from artificial manures required by the same quantity of each vegetable :* I Batata. I Eddoes. I Potato. -Pearl-ash . 18 Ibs. 4 oz. 19 Ibs. 12902. Epsoin-salts (Mg0.'S03 4iH0) . 3 54 -Glauber-salts (NaO. SO3+ 10 €10) .4 0 5 1 Common salt . . . .i 26 2 2 Gypsum (CaO. SO3+ 2 HO) . . 4 5;5 0 13 Bone earth . . . . . 5 13% 10 10 or Burnt bones . . . . 6 lbs. 5 02. 11Ibs. 15 02. 8 Ibs. ?$oz. :I 1 Bones (half-inch) . . . 9 13+ 18 6 112 94 The relative powers of exhaustion (if 1 may be allowed to use the expression) of these three crops for the most important of the inorganic constituents-the alkalis and phosphoric acid-may therefore be represented by the following numbers Alkalis.* Phosphoric acid. Potato . 217 or 1000 55$ or 1000 Eddoes . . 2444 or about 11263 81 or about 1459 Batata . . 233 , 10732 43$ )> 779

ISSN:1743-6893    

DOI:10.1039/QJ8510300193

出版商:RSC    

年代:1851

数据来源: RSC

摘要:

OF TEE BATATA AND THE EDDOES XXL-On the Bichromate of Ammonia und some of its Double Salts BY MESSRS HENRY R,RICHMOND AND JOHNS. ABEL Of the Boyd College of Chemistry. Being engaged a few weeks since in preparing some of the double salts of chromic acid described by Mr S. Darby in the Quarterly Journal of the Chemical Society,$ we were struck by the unusual and somewhat improbable nature of the formula NH,. 2 CrO, assigned by him to the bichrornate of ammonia. We therefore prepared a specimen of the salt and made several analyses of it the details of which are given below. We also prepared and analysed several double compounds vhich the bichromate of am-monia forms with protochloride of mercury. BICHROMATE OF AMMONIA. The bichromate of ammonia was prepared according to the direc-tions given by Mr.Darby. A strong solution of chromic acid was * In the construction of these formulae the oxide of iron and silica were not taken into consideration as it was supposed that all soils contain these substances in sufficient quantity to supply the wants of any plant not belonging to the graminece. t Including the alkaline chlorides and regarding them as free alkalis. $ VOl. I. p. 20. 200 ?&ESSRS RICHMOND AND ABEL divided into two equal portions one of which was saturated with ammonia ;the ttr o solutions mere then mixed and evaporated. As the chromic acid employed contained a large quantity of sulphuric acid the product of the first crystallization was very im- pure. It was of a brown colour but became perfectly yellow and Gpaque on drying This curious change could also be produced at once by pouring water over the crystals.After several recrystallizations the colour changed to a beautiful red and the crystals no longer became opaque under any circum- stances. For analysis they were powdered and dried in wacuo over sulphuric acid In determining the quantity of chromic acid we availed ourselves of the remarkable deportment of this salt when exposed to the influence of heat. Under these circumstances the salt is decomposed with evo- lution of nitrogen and water according to the following equation NH,O. 2 CrO = N + 4HO + Cr 0, or if we take the formula NH 2 CrO, NH3 2 CrO = N + 3 HO + Cr203. This decomposition was observed at an early period by Hayes and lately again by Bo ttger who noticed that the sesquioxide sepa- rated in this reaction presents a veiy peculiar appearance closely resembling mixed tea.In order to avoid all loss from the violent evolution of steam and nitrogen which was apt to scatter portions of the sesquioxide it was found convenient to insert a plug of asbestos into the glass tube in which the operation was performed the tube was subsequently drawn out so as to leave only a small opening for the escape of the gases. The ammonia determinations were made in the following manner a weighed portion of the substance was dissolved in a small quantity of water in a porcelain dish; hydrochloric acid and alcohol were added to reduce the chromic acid ;and the ammonia was precipitated by means of bichloride of platinum After evaporating nearly to dryness the residue was thrown on a filter and the sesquichloride of chromium was removed by mashing in the usual way with a mixture of alcohol and ether in which it is readily soluble Several other methods of determining the ammonia were tried without success.One of these consisted in distilling the bichromate with a solution of potassa the liberated ammonia being collected in the ordinary nitrogen bulbs. The results of this process were always too low owing to a portion of the ammonia remaining in the solution. In addition to the determinations of chromic acid and ammonia several hydrogen determinations were made by burning the salt with chromate of lead.ON THE BICHROMATE OF AMMONIA We have given below the calculated percentages of chromic acid and of ammonia for the formulae NH,. 2 CrO3J and NH,O. 2 CrO, It will be seen that the results of all the analyses agree pretty closely with the latter formula. Theoretical percentages Formula NH,. 2 CrO,. Formula NH 0.2 Cx03. Chromic acid . . 104.30 85.98 104.30 80.05 Ammonia . . . . l7*00 1+02 17.00 13.05 _L Water . . . -9.00 6.90 121.30 lOO*OO 130-30 100.00 Details of analyses CHROMIC ACID DETERMINATIONS* I. 0.8753grm. of salt gave 0.5393 grm. of sesquioxide of chromium Jj 11. 0.624 9) jj 0.385 $9 J? JJ 111. 0.2273 J9 1) JJ 001409 JJ JJ JJ AMMONIA DETERMINATIONS. IV. 0.3682 grm. of salt gave 0.641 grm.of the platinum-salt V. 0.1198 , 11 >J 0*204?d YJ JJ t1 VI. 0.2185 3) JJ JJ 0*3767 JJ JJ J> VII. 0.2515 3 ?J JJ 9g4332 JJ JJ JJ The percentage of chromic acid and ammonia calculated from these analyses is tabulated below. Calculated percentages I. 11. 111. IV. v. V? VII. Chromic acid 80.03 80.14 80.40 --Ammonia . --13.11 12.99 13-09 313.08 HYDROGEN DETERMINATIONS. VIII. 2.8217 grm. of the salt gave 0+3165 grm. of water jj JJ IX. 2.0455 , JJ 0.5752 The theoretical percentage of hydrogen for the formula NH,. 2 CrO is 2.47. The theoretical percenta&of hydrogen for the formula NH,O. 2CrO is 3.07. Analyses VIII. and IX. give respectively 3.21 and 3.12 per cent agreeing with the latter formula. In all the calculations we have taken the equivalent of chromium as 28.15 instead of 26.3 which is the number adopted by Mr.Darby The latter supposition reduces the theoretical percentage of chromic acid according to either formula by about 0.5 and slightly increases the percentage of chromic acid deduced from the amounts of sesquioxide of chromium found in the analyses These discrepan- MESSRS BICIEMOND AND ABEL cies however are by no means sufficient to account for the great difference between our results and those of Mr. Darby. We have made a few experiments in order. to ascertain whether the compound in question might lose an equivalent of water at looo and thus give rise to the formation of the substance which has been analysed by Mr. Darby :we have not however succeeded in obtaining such a compound.Leaving it therefore doubtful whether such a body actually exists we do not hesitate to conclude from the results of our own analyses that a compound of the formula NH 0. 2Cr0 does exist exactly corresponding to the potassa-salt KO. 2 CrO, with which it is most likely isomorphous. DOUBLE COMPOUNDS OF BICHROMATE OF AMMONIA WITH PROTO-CHLORIDE OP MERCURY. Having satisfied ourselves with respect to the constitution of the bi-chromate of ammonia we next turned our attention to the double salt which it forms with protochloride of mercury and to which Mr. Darby has assigned the formula NH,. 2 CrO,. HgCI. This salt presents itself in very different forms according to the strength of the solution from which it is crystallized.The first specimen which was prepared was deposited from a concentrated solu- tion in the form of small red needles closely resembling those of the bichromate of chloride of potassium. Several analyses of this salt gave rather uncertain results approaching however. most nearly to Mr. Darby's formula. As it seemed probable that a small quantity of uncombined protochloride of mercury was mixed with the salt we prepared another specimen in the following manner. About equal weights of the two salts were dissolved together in rather a large quantity of water; the solution being allowed to cool a portion of the protochloride of mercury separated and was removed. The solu- tion was then evaporated down just sufficiently to cause the formation of a few crystals on cooling.The salt obtained in this manner crystal- lized in beautiful large six-sided prisms of a splendid red colour The crystals were dried on blotting-paper and afterwards in vacuo over sulphuric acid. On further evaporation the liquid yielded a second crop of crystals in appearance exactly the same as the first which were likewise removed and dried. The mother-liquor was once more evaporated and on cooling deposited some more beautiful red crystals very much resembling the other crops but rather more inclined to the needle-shape; these crystals were also preserved and dried. On attempting to recrystallize portions of these salts it was found that a part of the protochloride of mercury crystallized out by itself',- ON THE BICHROMATE OF AMMONIA.whence it appears that it is necessary to have an excess of bichromate of ammonia in the solutionJ to obtain the salts free from uncombined protochloride of mercury. The products of these three crystallizations were analysed succes- sively in the order in which they were deposited. They all deflagrated on heating the protochloride of mercury being driven off together with the water of the nitrogen resulting from the decomposition of the bichromate of ammonia and pure sesquioxide of chromium remaining behind the first two salts deflagrated gently leaving the sesquioxide of chromium in the form of a dark powder which became green when strongly heated ; the third salt deflagrated violently swelling up to a great bulk and leaving the sesquioxide in large flakes of a dull green COIOU~J assuming the most fantastic shapes.CHROMIC ACID DETERMINATIONS BY IGNITION The chromic acid in these salts was determined in nearly the same manner as iu the bichromate of ammonia; but as they did not de-flagrate with such violence as the latter salt and as it waa necessary to apply a strong heat to drive off the whole of the protochIoride of mercury the operation was performed in a porcelain crucible instead of a glass tube DETERMINATIONS OF MERCURY AND CHROMIC ACID. The mercury was determined as protosulphide the chromic acid being reduced by means of hydrochloric acid and alcohol before passing the hydrosulphuric acid in order to avoid the precipitation of free sulphur.The chromic acid was also determined in the usual way by precipitating the sesquioxide by means of ammonia in the filtrate from the protosulphide of mercury. HYDROGEN DETERMINATIONS. In making the hydrogen determinations some precautions were neeessary for if the chloride of calcium tube had been placed as usual close to the combustion furnace the mercury would have been driven into it together with the water. To avoid this the combustion tube was drawn out in two places so as to form a kind of bulb in which all the mercury and the greater part of the water condensed. The chloride of calcium tube was attached in the usual manner beyond the bulb. After the combustion was completed all that portion of the com- bustion tube which projected from the furnace was cut off by means of a file at one of the narrow necks ;the chloride of calcium tube re- maining attached to it.The water was then swept into the chloride of calcium tube by means of a current of dry air drawn through by anaspirator. The mercury was dissolved and determined as sulphide. MESSRS. RICHMOND AND ABEL Details of analyses of the first salt CHROMIC ACID DETERMINATIONS BY IGNITION. I. 0.210 grm of the salt gave 0.0614 grm of sesquioxide of chromium. 11. 0.2205 ,> 3 0.0645 , >> 111. 0.2155 1) 2) 0.0634 , 3 DETERMINATIONS OF MERCURY AND CHROMIC ACID IV. 0.2565 grm. of the salt gave 0*1085 grm. of protosulphide of mercury and 0.0762 grm. of sesquioxide of chromium. Tr. 0.434grm of the salt gave 0.183 grm.of protosulphide of mercury and 0.1267 grm of sesquioxide of chromium. VI. 0.2243grm. of the salt gave 0*0940 grm of protosulphide of mercury. DETERMINATION OF HYDROGEN AND MERCURY VII. 0.6390 grm of the salt gave 0-1080 grm. of water (mercury lost.) VIII. 0.6440 , 39 OW60 ,, >, and 0.2720 grm of protosulphide of mercury. The following are the percentages calculated from these analyses I 11. 111 IV V. VIe VII. VIII. Chromic acid 38.00 38*00 38.19 38-08 37-9 --b Mercury . --36.49 36.36 36.20 -36-40 Hydrogen . -1.87 1.83 -_I--We had not anticipated the presence of more than one equivalent of water in this substance and it was on this account that we repeated the determinations of the various constituents several times.The formuh NH,O. 2 CrO ,HgCl and NH .2 CrO .HgCl appeared at the first glance to be the most probable; the former as an ordinary double salt of the bichromate of oxide of ammonium with protochloride of mercury corresponding to the potassa-salt to which Millon has assigned the formula KO. 2CrO,. HgCl the latter as representing a compound analogous to the bichromate of chloride of potassium containing in the place of potassium the hypothetical metal mercurammonium. The formula of the potassa-salt being KCl. 2 CrO, we should have NH 2Cr0,. HgCl = (N%)~~.2 CrO,. The comparison however of the percentages deduced from our analyses with those calculated from the preceding formula? and ON THE BICHROMATE OF AMMONIA* 205 from the formula NH,O.2 CrO,. HgCl + HO leave no doubt that the latter is the constitution of the salt as we obtained it. NH,O. 2 CrO,. HgCl ; NH,. 2 CrO HgCl ; NH,O 2 CrO,. HgCl I-HO. Chromicacid 39*24 40.61 37.96 Mercury . 37.62 38.94 36.39 Chlorine 13.35 13.83 12.92 Nitrogen 5.27 5.45 5.09 Hydrogen . 1-51 1.17 1*82 Oxygen (as water) 3*01 ---5.82 100-00 100*00 100*00 The product of the second crystallization proved to be identical with the preceding. I. 0.4215 grm. of salt gave 0.1215grm of sesquioxide of chromium corresponding to 37.94 per cent of chromic acid. TI. 0.463 grm. of salt gave 0.1954 of protosulphide of mercury corresponding to 36.39 per cent of mercury and 0.1354grm. of sesquioxide of chromium corresponding to 37.97 per cent of chromic acid.Another specimen of the salt was prepared which yielded the same results. Lastly the product of the third crystallization was analysed and yielded the following numbers I. 0.1880grm. of salt gave 0.0862grm of sesquioxide of chromium 11. 0.2093 ) 0.0958 >) ,f 111. 0.2068 ,) )) 0*0454 ) protosulphide of mercury IV. 0*2190 , ?? 0.0480 , >? >) Calculated percentages I. If. 111. IV. Chromic acid 59.52 59.43 - c . -18.91 18.90 Mercury . Theoretical percentages for the formula 3(NH40. 2 CrO,) HgCI Chromic acid . . . 59.44 Mercury . . . . 18.99 Ammonia . . 969 Water . . . 5.13 Chlorine . . . . . . 6.75 -100*00 It will be seen that the calculated percentages agree very closefy with those required by this formula.

ISSN:1743-6893    

DOI:10.1039/QJ8510300199

出版商:RSC    

年代:1851

数据来源: RSC

摘要:

206 MR GRIFFIN June 17 1850. THOMAS GRAHAM,EsQ. V.P. in the Chair. John Bennett Lawes Esq. and Frederick Vaux Esq. were clected Fellows of the Society. The following presents were annotrnced ‘‘Proceedings of the American Philosophical Society,” No. 44 presented by the Society. ‘(On a New Medium for Mounting Organic Substances as Per-manent Objects for Microscopic Inspection,” by Robert Warington presented by the Author. The following papers were read XXIL-Description of art Ammonia-Meter. BY JOHNJOSEPHGRIFFIN F.C.S. I take the liberty of presenting to the Chemical Society a Hydro-meter for determining the strength of solutions of Ammonia. think it may be interesting to the Society because it is founded on a chemical principle while its indications arc such as adapt it to the use of the manufacturer.In a memoir which the Society did me the honour to insert in their Transactions four years ago,* I recited some experiments to prove that mixtures of liquid ammonia with water possess a specific gravity which is the mean of thc specific gravities o€ their components; that in all solutions of ammonia a quantity of anhydrous ammonia weighing 212+ grains which I call a Test-atom displaces 300 grains of water and reduces the specific gravity of the solution to the extent of *OO125; and finally that the strongest solution of ainrrionia which it is possible to prepare at the temperature of 62O Fah. contains in an imperial gallon of solution one hundred test-atoms of ammonia. The new Ammonia-Meter is founded upon those facts.The form of the instrument is that of an ordinary glass hydrometer with a paper scale showing 100 degrees. Every degree indicates 1 test-atom or 212& grains of anhydrous ammonia in the gallon of solution. The zero of the scale signifies pure water at the temperature of 62O F. * On the Constitution of Aqueons Solutions of Acids and Alkalies hlem. Chem. SOC. 111 188 ON THE AMMONIA-METER. The first degree signifies 1test-atom of ammonia and the hundredth degree 100 test-atoms The specific gravity of the liquor which corresponds with 1000 of strength is 0875 water being taken at 1.000. TO render the indications afforded by this instrument useful to manufacturers I have prepared a table which shows the constitution of the hundred solutions of ammonia corresponding with the hun- dred degrees of the instrument.The table contains six columns of numbers. The first column shows the spec@ gravity of the solutions; the second column the weight of an imperial gallon in avoirdupois pounds and ounces ; the third the percentage of ammonia by weight; the fourth column the degree of the solution as indi- cated by the instrument corresponding with the number of test-atoms of ammonia present in a gallon of the liquor ;the fifth coluniii shows the number of grains of ammonia contained in a gallon ; and the sixth column the atomic volume of the solution or that measure of it which contains one test-atom of ammonia. The horizontal lines represent the various equivalents of every degree of ammonia indi- cated by the instrument.The Ammonia-iUeter and the Table together will enable a manu-facturer to determine not only the actual strength of any given liquor but the precise amount of dilution necessary to convert it into a liquor of any other desired strength. Thus a liquor indicating 96' by this instrument has a specific gravity of *88 and another indicating 32O has a specific gravity of 96. If the strong liquor is to be diluted to form the weak liquor the numbers in column 6 of the table show that 104-16measures of the former must be diluted to 312.5 measures of the fatter. The direct quotation of the number of grains of ammonia contaiiied in a gallon of solution enables one to judge at a glance of the money value of any given sample of ammonia.Finding that a liquor at 33O contains about one pound of ammonia; a second liquor at 66u two pounds; and a third at 990 three pounds in the gallon we perceive at once the relative value of these liquors. The degrees of this instrument mark the strength of solutions of ammonia in a more comprehensible manner than is done by a state- ment of their Specific Gravities. Thus the weak liquid ammonia of the London Pharmacopoeia has a specific gravity of *96 and that of the Dublin Pharmacopmia. a specific gravity of -95. A gallon of the latter weighs only 1-&ounce less than a gallon of the former. These comparisons do not appeay to indicate any great differmce in the strength of the liquors; yet the new Ammonia-Meter marks the London ammonia as of 32O and the Dublin ammonia as of 40°;and 208 MR.QRIFFIN the respective strengths of the liquors agree with these numbers the Dublin solution containing 25 per cent more ammonia than the Lon- don solution. In proposing to determine the strength of solutions of am-monia by a hydrometric process I do so in accordance with the practice of chemical manufacturers; but I may add that in point of accuracy the best hydrometer that can be made stands for such a purpose far behind the cheniical process of centigrade testing. This arises from the fact that the density of ammonia in solution closely approximates to the density of water. A gallon of water weighs only 20 ounces more than a gallon of the strongest solution of ammonia.The extreme difference between the specific gravities of the two liquids is only *125. Every degree of the Ammonia-Meter shows the hundredth part of that difference and therefore indicates an alteration equal to + of an ounce in 10lbs. of water or the 800th payt of the entire weight. As a hydrometer of many spindles is ex- pensive and troublesome and as a single spindle cannot conveniently carry above 100 degrees this instrunlent may be said to exhaust the capabilities of such a mode of trial;-but centrigrade testing applied to ammonia readily discriminates ten degrees of chemical strength between each of the hydrometric degrees. The following precautions are necessary to be taken in using the dmmonia-Meter 1,The instrument must not be warmed by the hand before inser- tion into the liquor to be tried.-2.The spindle must not be unne- cessarily wetted by the liquor to prevent this the instrument in a dry state should be put gently into the liquor and the jar or table be tapped till the hydrometer sinks to the proper level,--3. The lines on the scale are drawn level with the general surface of the liquor under trial not with the liquor which capillary attraction draws up round the spindle.-4. It must be borne in mind that when the so-lution of Ammonia has been made with undistilled water the ap-parent strength will be less than the real Strength according to the increase of density due to the impurities contained in the water.* * The specific gravity of the Thames water at Greenwich is 1*00116 (Bennett Chem.SOC. Qu. J. 11 log) and that of London Well-water is 1.0007 (Brande ibid 11 349). Liquid ammonia prepared with the former would be lo,with the latter +o stronger than the degree indicated by the instrument T,QGLE OF LIQUID A&I&!lQNIA. One Test-Atom of Anhydrous Ammonia = NH weighs 2125 grains. Sp. Gr. of Water = 1*00000. One Gallon of Water weighs 10 lbs. and contains 10,000 Septems. Temperature 62O Fahr. H-W I-! %'eight of j. r Septems Weight of Id. Weight of :.r 2 Specific an imperial ercen tage i.22 hains of :on tainine Specific an imperial 'ercentage i: g Grains of Septems Specific an imperial 'ercentage $ .s-0 2raius of Septems mmonia :ontaining *J gravityof gallon in of ;g$ immonia test-atoE :ravity of gallon in of i gz smmonia ontoining :ravity of gallon in of test-atom '2 the liquid avoirdu-immonia in one of he liquid avoirdu-ammonia '& in one test-aton he liquid avoirdu-ammonia ;82 in one of ammoma.pois Ibs. by weight. ;gE gallon. mmonia. rmmonia. pois Ibs. )y weight. ;EE gallon. Of immonia. .mmonia. pois lbs. 'y weight. *EaJ gallon ammonia. and 02s. and ozs. ama and ozs. !s5 !--$7500 3 Ib. 12-02 34,694 100 21250.9 100~00 *91750 9 lb.2'8 02. 21.837 66 14025.0 151.51 -95875 9 Ib. 9.40~. 1@4490 33 7012.5 30303 -87625 d .. 12.2 .. 31,298 99 21037.5 101*01 -91875 9 .. $0 .. 21,477 65 13813 5 15385 -96000 9 .. 9'6 .. 101190 32 6800 0 312.50 %7750 8 .. 12.4 ,. 33'903 98 20825 0 102*04 -92000 9 *. 3'2 .. 21.118 64 1:3rjuo*o 156 25 '96125 9 ..9.8 .. 9 7901 31 6587.5 Y22.58 -87875 8 .. 12.6 .. 33.509 97 20613 5 10:3*09 %?I25 9 ..3.4 .. 20.760 63 133875 158'73 '96250 9 ,. 10.0 .. 9.4620 30 6375.0 333.38 *880"0 6 .. 12.8 .. 33 117 96 20400*0 104 16 *YWiO 9 ..3.6 .. 20 403 62 13175*0 16129 ,96375 9 .. 108 *. 91347 29 6162.5 !$4 83 '88125 8 .. 130 .. 32*725 95 20187.6 106.26 -92373 9..38 .. 20.046 61 1291;2*5 163.93 '96500 9 ..10.4 .. 8.8083 28 5950.0 &7*14 *83250 8 ..13.2 .. 52335 94 19975 0 106.38 -92500 9 .. 40 .. 19 691 60 12750 0 166 67 56625 9 .. 106 .. 8 4827 27 573745 370.37 *88375 8 *. 13'4 .. :i1*916 93 19762.5 107.53 *92625 9 ..4'2 .. 19 337 59 12537.5 169 49 96750 9 *. 108 *. 8.1560 26 3925.0 384 62 w500 8 ..13% .. 31 558 92 19550'0 108.70 *92750 9 ..44 .. 18 983 58 12325 0 li2.41 '968i5 9 ..11.0 ..7.8341 25 5312.5 40OS00 -88625 8 ..13.8 .. 31.172 91 19337.5 109.89 ,92875 9 ..4.6 .. 18 631 57 12112 5 175.44 *97000 9 .. 11.2 .. 75111 24 5100 0 416.67 '88750 8 .. 14.0 .. 30.785 90 19125.0 111'11 *93000 9 .. 48 .. 18280 56 11900~0 178.57 '!)7125 9 .. 11.4 .. 7.1888 23 4887'5 434-7s -88875 d .. 14-2 .I 30400 89 1891235 112.36 -93125 9.. 50 .. 17 929 a5 11687.5 181'82 -97250 9 .. 11 6 .. 6 8674 22 4675 0 45454 -89000 8 *.144 30 016 85 18700.0 11364 *932.50 9 .. 6.2 .. 17'579 51 114i5.0 185.18 '97375 9 .. 11.8 *. 6.5469 21 4462 5 476.19 -89125 8 .. 14% .. 29 1%~ 87 18187'5 114 94 -93375 9 .. 5.4 .. 17*23I 53 11262 5 18@68 w500 9 .. 12.0 .. ti.2271 20 4250.0 500.00 '89250 8 .. 11.8 .. 29'2.32 86 18275.0 116% *93500 9 ..5.6 .. 16.883 52 11050'0 192.31 *9ifi25 9 ..12.2 9. 5 YO82 19 4037 5 52632 .S93i5 8 .. 15.0 .. 28 s71 85 18062.5 117.65 99625 9 .. 5.8 .. 16'536 51 10837'5 196 08 '97750 9 .. 12.4 .. 5 5901 18 3825 0 555.56 -89500 8 .. 15-2 .. 23'4'32 84 1i850.0 119.05 *93750 9 ..6.0 .. 16.190 50 10625 0 200 00 *97875 9 .. 126 *. 5 %728 17 2613 5 668 24 -89625 d .. 15.4 . 28.113 83 17637'5 120-48 -93875 9.. 62 -. 16.846 49 10412'5 204.03 '9x000 9 .. 12.8 .. 4'Y563 16 3400 0 625.00 '89750 8 .. 15.6 . 27.736 82 17425.0 121% .91000 9 ..6.4 .. 15 502 48 10'2c0.0 20fP33 *98l25 9 .. 13-0 .. 4 6406 15 3187.5 666.67 -89875 8 ..15% .. 27.359 81 17212.5 123.46 *94125 9 ..66 15.158 47 9987 5 212.77 '93250 9 .. 132 .. 4.3255 11 2975.0 714 29 a-'90000 9.. 00.. 26984 80 17000.0 125.00 942550 9a.68 .* 14.816 46 9775'0 2 17.39 * 98375 9 ..13.4 .. 4 0116 13 2762.5 769.25 -90125 9 .. 0.2 .. 26.610 79 16787.5 126.58 '94375 9..70 *. 14.475 45 9562'5 222 22 '93500 9 .,136 *. 3'6983 12 2550 0 833.33 -90250 9 .. 0.4 .. 26%7 78 16575.0 128.21 '94500 9 ..7.2 .. 14.135 44 93500 227'27 -98625 9 .. 138 .. 3.3858 11 2387 5 909.09 -90375 9 .. 06 . 25 865 77 16362.5 129.87 W625 9 ..7.4 .. 13 795 43 9137'5 232 56 *Yir750 9 .. 14.0 .. 3,0741 10 2125 0 1000~00 '90500 9 ..I 0'8 .. 25.493 76 1615OqO 131.58 -9.4750 9 .. 76 .. 13.456 42 8925'0 238 09 '988T5 9 *. 14.2 .. 2'7632 9 1912 5 1111.10 90625 9.. 10.. 25.123 75 159317'5 1:33.;33 -91875 9 ..78 .. 13'119 41 8712.5 24) 90 '99000 9 .. 144 .. 2.4531 8 li00 0 1250.00 90750 9 .. 1.2 .. 24.754 74 15725.0 135.13 *95000 Y ..8.0 .. 12'782 40 8500 0 250 00 '99 125 9 ..146 ..2-1438 7 1425.60 -90.75 I).. 1.4 .. 24386 73 155125 136.93 *!J5 125 9 ..8.2 .. 12.446 a9 8287'5 256.41 '99250 !) .. 148 .. 18352 6 ?P,F1666 70 Id3 0 '91 000 9 .. 1,6 .. 24.019 72 15300 0 138*89 *95250 9 ..84 .. 12 111 38 8075'0 263 16 '99375 9 .,15.0 .. 15274 5 1062.5 200000 ,91125 9 .. 1.3 .. 23'653 71 15087.5 140.85 95;m 9 ..8.6 .. 11 '777 37 7862'5 270 27 '99500 9 .. 15.2 .. 1.2204 4 P50 0 ?!op'oo * 91250 9 .. 2.0 .. 23.288 70 14875.0 142 86 '95500 0 ..8.8 .* 11'444 ::6 7650'0 277.78 '99695 9 .. 15.4 .. 0'9141 a 637 5 i3.W su *91375 9 .. 2'2 .. 225m 69 1466'25 141*93 '95625 9.. 90 .. 11'111 35 7437'5 285.71 '9!)750 9 .. 15.6 .. 0 6087 2 425.0 5000~00 -91500 9 .. 3.4 .. 22.66 I 68 14450*0 19-06 ,95750 9 ..9'2 .. 1W780 31 7295'0 291.14 '99875 9 ..158 .. 0-3040 1 212.5 1000000 '91625 9 .. 2.6 *. 22.198 67 14237.5 14925 1*0000 10 lbs. Water. 0 1. 2. 3. 4. 5. ti. 1. 2. 3. 4. 5. 6. 1. 2. 3 4. 5. 6.

ISSN:1743-6893    

DOI:10.1039/QJ8510300206

出版商:RSC    

年代:1851

数据来源: RSC

摘要:

MESSRS. BRAZIER AND GOSSLETH XXlII.-Contributions towards the history of Caprob and CEnanthylic Acids. BYMESSRS.J. S. BRAZIER AND G. GOSSLETH Of the Royal College of Chemistry London. The leading notions which begin to elucidate the vast number of observations collected in the department of organic chemistry have been acquired in the careful study of a comparatively limited number of groups of analogous substances. The investigation of a series of bodies closely allied to each other in their composition and proper-ties and a comparison of their cornposition and properties im-parted to the results obtained a degree of interest which could not have been possibly claimed by the most accurate and minute exami-nation of an isolated compound. Among the groups of substances the study of which has thus most materiaIly assisted in the elaboration of our theoretical views the series of acids usually called fatty acids appears in the first rank.This series commencing with formic acid the simplest of all organic acids and terminating with an acid of so high an equivalent 88 rnelissic acid discovered by Mr. Brodie,* is at once distinguished by the definite character of its members by the extent to which it is represented by well-investigated terms and by the variety of sources belonging to almost all the various departments of organic chemistry from which these terms have been derived. Descending from the alcohols by way of the aldehydes and connected with the former group in another manner by the nitriles again related in its deriva- tives with marsh-gas and its homologues as well as with the increas- ing family of acetones the history of this group when traced in its various ramifications extends over a field on which we meet with almost all the compounds esseutially concerned in the progress cf chemical science.In the following pages we beg to communicate to the Society a few contributions towards the history of the fatty acids which not-withstanding their fragmentary nature may be acceptable on account; of the interest attached to the subject. These communications refer to the sixth and seventh term of the series of fatty acids namely caproic and ananthylie acids. CAPBOIC ACID. This acid discoyered by Chevreul in the course of his unforgotten researches into the nature of fatty bodies and subsequently met with ON CAPROIC AND (ENANTHYLIC ACID.in cocoa-nut oil by Fehling,* has been produced of late under very remarkable circumstances from cyanide of amyl by Messrs. Kolbe and Frankland.? In order to avoid the tedious processes of saponi-fication and subsequent fractional distillation of the volatile products or of separating the acids by the different solubility of their baryta- salts we resolved to prepare the acid by the latter method. In the course of this process we made one or two observations which may be mentioned. The sulphamylate of potassa used in making cyanide of amyl was prepared at once from sulphamylic acid by saturating it with crude carbonate of potassa.Nearly the whole of the excess of sulphate of potassa formed was separated during this operation the remaining portion crystallizing out by the evaporation of the solution. The perfectly dry sulphamylate of potassa when distilled with cyanide of potassium in the proportion of three to one yields cyanide of amyl. In the commencement we performed this distilla- tion on a rather considerable scale in iron retorts the irregular action of the heat however induced the formation of a large amount of secondary products; and we found it more advisable to work with smaller portions. The operation succeeds very well in Florence flasks placed obliquely upon a wire-gauze over a gas-burner. The liquid obtained in this distillation is by no means a definite compound.Its terrible odour indicates at once the presence of a considerable amount of prussic acid. When subjected to distillation it begins to boil at about lZ5OC (257O I?.) the boiling-point rising gradually to 150' C (302OF.) about which temperature a semi-solid yellowish- white mass of crystalline appearance remains behind in the retort. A similar product is deposited in the tube of the condenser. It may here at once be stated that this liquid contains in addition to cyanide of amyl a pod deal of fusel-oil and moreover a considerable quan-tity of both liquid cyanate and solid cyanurate of amyl the ti*o latter evidently arising from the presence of a large amount of cya-nate of potassa in the commercial cyanide of potassium. This sub-stance which is now manufactured in this country by hundred- weights is invariably prepared by Liebig's process the success of which as is well known actually depends upon the simultaneous for- mation of the cyanate.In the first place we attempted to purify the crude cyanide pre- viously to its conversion into caproic acid ;but after having ascertained * Ann. Ch. Pharm. LIII 390. f Ann. Ch. Pharm. LXIX 418. P2 MESSRS. BRAZIER AND GOSSLETH the nature of the impurities we at once subjected the crude product collected between 130° and 150° to the action of the alkali. The products of decomposition furnished by the cyanide and cyanate are so opposite in their chemical character-the one yielding a strong acid caproic acid the other a powerful base-amylamine or valera-mine-while the fusel-oil present remains unaltered-that the separation after decomposition follows as a matter of course whilst separation by fractional distillation before the action would have been a tedious and nevertheless imperfect operation.The conversion of the cyanide of amyl may be effected by an aqueous solution of potassa we found however that the operation succeeds much better with a solution of the alkali in alcohol. The mixture when boiled in a flask connected with a condenser in such a manner as to induce the liquid to return to the alkali readily changes into a pasty mass while torrents of ammonia are evolved. After half an hour's ebullition the mixture is introduced into a retort and subjected to distillation when a small quantity of am-monia alcohol amylamine and fusel-oil distil over a solution of caproate of potassa remaining behind which usually solidifies on cooling into a semi-crystalline mass.The distillate was mixed with some hydrochloric acid and sub- jected once more to distillation; it began to boil at about 78O C. (17ZU*4F.) the first product consisting of alcohol ;the boiling-point rose gradually to 131O C. (267O.8F.) at which temperature pure fusel- oil distilled over a syrupy mass remaining behind containing chiefly hydrochlorate of amylamine and from which an additional quantity of fusel-oil was separated by addition of water. The dilute solution when boiled for some time in order to drive off fusel-oil which was still mechanically adhering and distilled with potassa yielded a considerable quantity of pure amylamine.The production of this base under these circumstances is as we have mentioned due to the decomposition of the cyanate and cyanurate of amyl these substances as Wurt z has shown assimilating the elements of water are split up into carbonic acid and amylamine. In several operations the production of the latter base nearly equalled the quantity of caproic acid obtained which shows how much cyanate is present in many kinds of commercial cyanide of potassium. With respect to the properties of amylamine we have scarcely to add anything to Wurtz's description j however as we had a considerable quantity of the substance at our disposal we determined its boiling-point with accuracy.Amylarnine boils constantly at 93' C. (199O.4F.) We adduce moreover an analysis of the platinum- ON CAPROIC AND (ENANTHYLIC ACID. salt of this base which leaves no doubt as to its identity with amylamine. The platinum-salt being soluble in water was easily purified by one or two recrystallizations. I. 0.5722 grms. of platinum-salt gave 0.4259 , , carbonic acid and 0.2578 , , water. 11 0*6210 , , platinum-salt gave OS2077 , , platinum These numbers lead to the following percentage which we place in juxtaposition with the theoretical values of the formula C, H, N. HCI. 1%Cl,. Theory. Experiinent . 10 eqs. of Carbon . . 60-00 20.46 20.30 14.00 4-78 5-00 14 , , Hydrogen . I 1 , , Nitrogen . . f&OQ 4-78 3 , , Chlorine .. . 106.50 36.33 -) Platinum . . 1 98.68 33.65 33.45 > 1 eq. of Bichloride of Pla-293,114; loo,oo tinum and Arnylamine The solution of caproate of potassa concentrated if requisite by evaporation was gradually mixed with sulphuric acid when caproic acid separated as an oily liquid lighter than water. It was removed by a tap-funnel and subjected to rectification. The acid obtained in this manner was not perfectly pure; when submitted to distillation it was found that the thermometer rose at once to and became constant at 198O C. (388O.4F.); at which tem- perature the larger portion of the fluid distilled over ; the mercury then rose gradually to 211O C. (411O*8F.) The first fraction when rectified exhibited exactly the same boiling-point as before several ounces distilling over without any oscillation of the mercury whence we do not hesitate to consider 198O C.(388O.4F.) as the boiling- point of caproic acid Fehling'g had found that the acid obtained from cocoa-nut oil boiled at 202O C. (395O.6 F.) CAPROATE OF AMYL. We have just stated that the thermometer continued to rise after the distillation of the pure acid. The product passing over between * Anu. Ch. Pharm. LIII 390. MESSRS. BRAZIER AND GOSSLETH 200°and 2114 differed in its odour from that of caproic acid; it was found to be partly soluble in alkaline and not at all in acid liquids and formed only a comparatively small percentage of the total amount of liquid. In order to obtain a sufticient quantity of this compound for examination a considerable portion of crude caproic acid was treated with a solution of carbonate of potassa when the caproic acid was dissolved with evolution of carbonic acid an oily liquid separating on the surface of the solution.When removed with a separating funnel and dried over chloride of calcium it exhibited after rectification a constant boiling-point at 211O C. (411°*8F.) The analysis of the oily liquid gave the following results I. 0.2485 grms of substance gave 0.6410 , , carbonic acid and 0.2675 , , water. 11. 0.2075 , ,)substance gave 0.5386 , , carbonic acid and 0.2231 , , water. Percentage-composition I. 11. Carbon . 70.75 70.80 Eydrogen . 11.95 11*94 These numbers closely agree with the formula as exhibited in the following comparison of the theoretical values with the results of experiment Theory.Mean of Experiment. -22 eqs. of Carbon . . 132 70.96 70-78 22 , , Hydrogen . . 22 11.82 11.94 4 ,) , Oxygen . . + 32 17.22 -186 100.00 The formuh c22 If22 04 represents the composition of caproate of amyl Cl Hn*Cl Hl 0,. The observed boiling-point of this compound coincides pretty closely with the number calculated if we start from the boiling-point of valerate of amyl which according to I3 alard’s determination ON CAPROIC AND (ENANTHYLIC ACID. 215 is 190° C. (374OF.) The deportment of the above substance with an alcoholic solution of potassa leaves no doubt in this respect. The mixture when heated was readily converted into a gelatinous mass from which water separated pure fusel-oil while addition of sulphuric acid to the remaining alkaline solution induced the liberation of an oily acid which by analysis was proved to be caproic acid.When it was separated by distillation dissolved in ammonia and converted into a silver-salt 0*2814grms of silver-salt gave 0*1408 , ? silver = 48.65 per cent. of silver. The formula At5 Cl HI 043 requires 48-43per cent. Caproate of amyl has a very disagreeable smell and pungent taste is perfectly insoluble in water of a lower specific gravity but soluble in every proportion of alcohol and ether. The formation of caproate of amyl under the adduced circm- stances appeared at the first glance rather enigmatical.We soon found however that fusel-oil is soluble to a certain extent in a soh-tion of caproate of potassa. The separation of caproic acid by sd-phuric acid in the presence of amyl-alcohol could not fail to produce a certain quantity of the compound ether in question. ACTION OF HEAT UPON CAPROATE OF BARYTA. The members of the series CnH O, when subjected to the action of heat split as is well known into water carbonic acid and a new class of bodies known under the name of acetones or ketones according to the following equation Cn Hn 0,Z= HO + Cog + C(n-1) H(n-1) 0 lThis metamorphosis is generally effected by the distillation of the lime-or baryta-salts in which case the carbon becomes fixed in the form of a carbonate.In preparing the ketone of caproic acid we availed ourselves of the baryt a-sal t . This salt is easily prepared by means of carbonate of baryta and caproic acid; it is very soluble in water. The solution when left to evaporate in vacuo over sulphuric acid deposits crystalline plates. By ebullition the odour of caproic acid becomes perceptible and a white mass separates which can be dried without decomposition at a temperature a little above 1000C. The dry mass evidently a 216 NESSRS. BRAZIER AND GOSSLETH somewhat basic salt is brittle and may be easily powdered; for the distillation of the salt we employed small quantities at a time. At a gentle heat the salt fuses without charring in the least nearly white carbonate of baryta remaining behind ;nevertheless only a compara-tively small quantity of liquid product is obtained as distillate.Experiment showed at once that the action by no means consists exclu- sively in a separation of carbonic acid ; for during the whole process a permanent inflammable gas was evolved the quantity of which appeared to increase in some measure with the temperature at which the distillation was performed. Caproate of baryta when suddenly exposed to a rapidly rising temperature disengages this gas in con-siderable quantities only a small portion of oily products being formed which are moreover very dark and resinous whilst the distillate obtained at moderate temperatures is nearly colourless. The carbonate of baryta which remains in the retort is nearly black from separated carbon !J%ese facts as well as the observations made by Chancel and Guckelberger* in the analogous decomposition of butyric valeric and caprylic acids left no doubt that the liquid pro- duct was a mixture of various substances.When dried over chloride of calcium and subjected to distillation it commenced boiling at 120°C. (248OF.) the boiling-point rising gradually to 170°C. (338O F.) Between 160° and 170° the largest quantity was collected. This portion 011 rectification showed a pretty constant boiling-point at 165O C. (329OF.) With the lower portions no constant boiling-tem- perature could be observed. Several combustions made with this product exhibited invariably a deficiency of carbon when compared with the percentage of carbon required by the formula0 f caprone CI1H, 0.This as well as the results of Chancel who actually separated butyrale or at all events a substance of similar composition from the product of distillation of butyrate of lime lead us to believe that a small quantity of caprale CIz H, 0, may be formed in this process. This assumption is supported by the deportment of the lower dis- tillate from which ammonia removes a small portion of matter. The ammoniacal solution after having been exposed to the air for some time yields with acids oily globules having the characteristics of caproic acid. Unfortunately we had not enough material to elabo- rate this question any further. We were however benefitted by the observation inasmuch as it induced us to submit the chief fraction boiling at about 165O previously to analysis to an addi- * Ann.Ch. Pharm. LXIX 20. ON CAPROIC AND CENANTHYLIC ACID. tional distillation over hydrate of potassa. After this treatment it showed a constant-boiling point at 165O C. (329OF.). When burnt with protoxide of copper this liquid gave the following results I. 0.1641 grms. of substance gave 0.4655 , , carbonic acid and 0.1949 , , water. If. 0.2263 , , substance gave 0.6423 ,) , carbonic acid and 0.2668 , ) water. Percentage-composition 1. 11. Carbon . . 77.36 77.42 Hydrogen . . . 13.18 13.10 These numbers closely correspond with the formula Cll H1,0 as may be seen from the following table Theory. Mean of Experiment.11 eqs. of Carbon 66 77'64 77.39 11 , Hydrogen 11 12-94 13-14 1J 1) Oxygen 08 9-42 -I eq. tt Caprone . 85 100*00 Caprone is a very mobile liquid insoluble in water to which however it imparts its peculiar oiour-; it is readily soluble in alcohol and ether. After being distilled from potassa it is perfectly colourless but rapidly turns brown when in contact with the atmosphere pro- bably in consequence of oxidation. Its boiling-point is 165O C. (329OF.),and its specific gravity is lower than that of water. These results show that one phase of the action of heat upon caproate of baryta may be represented by the equation Ba. C, HIl 0,= Ba. CO i-C, H, 0. We say one phase because a series of other metamorphoses is pro-ceeding smultaneously with the conversion of a portion of the acid into caprone.The amount of this substance obtained is quite out of pro-portion with the quantity of baryta-salt employed. We have men-tioned that we have reason to believe that the aldehyde of caproic acid is simultaneously formed and alluded to the large quantity of permanent gas disengaged. This gas consists chiefly of hydrocar-bons and probably contains a similar mixture of the hydrocarbons 218 MESSRS BRAZIER AND GOSSLETH C H, which Dr. Hofmann observed in the distillation of valerianic acid.* The preparation of caprone adds another member to the group of ketones running parallel with the series of fatty acids. This group first announced in the formation oi" acetone which may be still con-sidered as its prototype and subsequently illustrated by Chancel's researches into the derivatives of butyric and valeric acids embraces at this moment the following members which we give in juxtaposi-tion with their mother-acids Acetic acid .. C €3 0,;C H 0 Acetone; Liebig & Dumas Propionic acid. Propioue ; Metacetic acid. O'{ Metacetone; FrBmy. } . C '6 '6 '4; '5 H5 Butyric acid Hs 0,;C H 0 Butyrone; Chancel. Valeric acid . . C, HI*0,;C H 0 Valerone; Chancel. Caproic acid . . C, H, 0,; C, HI 0 Caprone ; G. & B. Caprylic acid . c16 0,; C, H, 0 Caprylone; Guckel-berger. C, H, 0,;C, H, 0 Margarone ;Bussy. Margaric acid . This table shows that the ketone of formic acid is still wanting; the series then regularly ascends up to cmanthylic acid whose deri- vative has not yet been prepared; we perceive moreover that a wide gap occurs between caprylic and margaric acid the filling up of which will require some time and labour.It deserves to be men- tioned that one of the terms which we have inserted in the above table has not hitherto been obtained from the collateral acid. Propione (metacetone) originally prepared by Prkm y by distilling sugar starch orgum with lime has been represented by its discoverer by the formula c6 H 0; it is probable however that Fre'my's substance contains one equiv. of carbon less. Its properties coincide in almost every respect with propione as pointed out by theory. Acetone and its congeners have been of late the subject of some interesting speculations on the part of M.Chance1.t The formula which we have given in the above table represents 2 volumes of vapour and this is the mode of condensation adopted by the majority of chemists. M. Chancel on the other hand is of opinion that the ketones like the hydrocarbons contain 4 vols. of vapour he doubles * The chief component of this gas is as I have stated propylene. I have since learnt from M. Cahours that pelargonic caprylic and cenanthylic acids likewise yield this hydrocarbon in preponderating quantities so that we may fairly assume that caproic acid exhibits a similar deportment.-A. W. H. -$-J. Pharm. [3] XIII,468. ON CAPROIC AND GNANTHYLIC ACID. 219 the formulze and considers these substances as formed by the intimate combination of 1 equivalent of the aldehyde of the acid with 1equi-valent of the hydrocarbon belonging to the group which is placed a step lower on the ladder of organic substances.According to this view acetone is not represented by c H 0 but by C H6 0,= C4 H4 0,+ C H:,; i. e. it has to be considered as a combination of the aldehyde (par eweZZence) and methylene consequently the ketones would always arise from the decomposition of 2 eqs. of the respective acids 2 Cn Nn 0,=2 HO + 2 CO + C H 0%+ Cln-2) The following table into which we introduce the boiling-points which have been observed exhibits the various ketones when viewed in this light Boiling-point. Acetone . C H O:,=C €I4 0,+C2 H:,..56OC. (13Zoo8F.) Propione .C, H, O,=C H6 O,+C H .. 84' C (183O*2F.) Butyrone . C14 HI4 O,=C H 02+C6 N . . 144O C. (291'3 F.) Valerone . C, H, 0,=C1 H, O,+C H Caprone C, H, 02=C12 H, 02+C, HI,. . 165' C. (329O.OF.) Caprylone. C30 Hs0 02=C16 H16 02+C, H,,,. . 178O C (352O*4F.) Margarone C Ha6 o,=c34 H, 02 +C3 H3 Chancel's view is chiefly supported by the deportment of some of the ketones under the influence of oxidizing agents. In fact acetone when boiled with chromic acid yields a mixture of acetic and formic acids the former being (in the conception of this theory) derived from the aldehyde while the latter is due to the presence of a term belonging to the lower series If acetone were C H 0,this conver- sion would be almost unintelligible.In the same manner propione is converted into propionic and acetic acids By treating butyrone with nitric acid C hancel* obtains nitropropionic acid which may have been formed by the oxidation of the propylene; Chancel gives no account of what becomes of the other term the butaldehyde occurring in his formula. On the other hand we find that the formation of butyrone is invariably attended by a simultaneous production of butal-dehyde (butyrale) which may be due to a partial decomposition of the butyrone in the nascent state probably with evolution of propylene. The generation of valerone and as we have seen of caprone gives rise * J. Pharm. [S] XIII 463. 220 MESSRS. BRAZIER AND GOSSLETH to similar phenomena. It remained now to study the deportment of the latter compound under the influence of oxidizing agents.ACTION OF NITRIC ACID UPON CAPRONE This body mas very readily attacked by nitric acid. If strong acid was employed oxidation ensued without the application of heat as soon as the evolution of nitrous fumes had ceased the liquid in the retort was saturated with carbonate of potassa when an oily liquid of a peculiar aromatic odour separated which was insoluble in an excess of the alkaline liquid. The quantity at our disposal was so very small as to preclude altogether the possibility of a closer examina- tion. The alkaline solution separated from the oil by ebullition was now acidified with sulphuric acid and subjected to distillation when an acid liquid was obtained upon which a small quantity of an acid oil was floating.When saturated with ammonia and precipitated with nitrate of silver a white crystalline silver-salt was obtained. The quantity of material at our disposal was just sufficient for a silver-determination 0,4566 grms of silver-salt gave 0*1088 ,9 ,,silver. Percentage of silver 42.29 This number although somewhat low would indicate that tbe salt analysed was nitrovalerate of silver ; the slight deflagration which occurred on igniting the salt gives further evidence in favour of this view The formula requires 42.5 of silver. If the acid formed by the action of nitric acid upon caprone be actually nitrovaleric acid-which has to be proved by additional experimental evidence-the deportment of this ketone would be per- fectly analogous to that of butyrone which yields nitropropionic acid.In both cases we may ask what becomes of the aldehydes which accordins to the analogy of the lonw terms should be con- verted into their correlative acids namely into caproic and butyric acids. These acids which according to Chancel’s formula should be formed in quantities equal to those of uitrovalerk and nitropro- pionic acid and which should be produced even more readily than the latter acids have not as yet been observed in the respective pro- cesses Hence it appears that many further researches are requisite ON CAPROIC AND CENANTHYLIC ACID. 221 in order to establish Chancel’s interesting speculations. The chief difficulty which we meet in the study of’ the higher terms of this series is the great amount of acid required the preparation of which is both laborious and expensive.Before leaving this question we may still take a glance at the boiling-point of the substance under consideration. The difference of the boiling-point of acetone and butyrone 144O-56O =88 = 4x 22 agrees very well with C hancel’s view ;the boiling-point of propione is stated at 84O instead of loou which would be the temperature assigned by theory. However as propione has never been prepared from propionic acid we can scarcely place implicit reliance upon the statements at present in our possession; it is possible that the pro-duct investigated produced as it was in an irregular process of destructive distillation still contained some of the substances simul- taneously generated acetone &c.The boiling-points of caprone and caprylone (Guckelbefger) are not at all favourable to Chancel’s assumptiml. Caprone boiling at 165’ (3. (329OgOF.) should according to theory boil as high as 232O C. (499O.6 F.) ; caprylone the theoretical boiling-point of which is 320° has been found to enter into ebullition at as low a tem-perature as 178O C. (352O-4F.). We have however to bear in mind that the present state of our knowledge respecting boiling-points is very deficient; the empirical rule at which we have arrived holds good only for a certain range of the thermometer the difference of the boiling-temperatures increasing towards the lower and decreasing towards the upper liiizit.We have to apologize for the unsatisfactory state in which we are obligcd to leave this question for the present we say for the pre- sent because it is our intention to return to this subject as soon as possible. We hope more especially soon to obtain additional data respecting the composition and tbe properties of nitrovaleric acid. The deportment of this acid under the influence of reducing agents promises interesting results; for should this acid -as we have every reason to believe-imitate the behaviour of nitrobenzoic acid,* its analogue in the benzoyl-series it will put us in possession of carbobutylic acid from which a single step downward would lead to butylaniine. * Benzoic acid . . C, €1 0,. Valerie acid . . . .C, W, 0,. Nitrobenzoic acid . C14{ 20,}04. NitrovaIeric acid . Clo{ zb4}0,. Carbanilic acid . . C, EH2 0,. Carbobutylic acid . . . C.{ ?H,} 0,. i51 Aniline CI2 H,. N Butylamine (Petinine) C HI1 N 222 MESSRS. BRAZIER AND GOSSLETH DECOMPOSITION OF CAPEOIC ACID UNDER THE INlLUENCE OP THE GALVANIC CURRENT. Among the various derivatives of the series C H 0, few have created more interest than the substances which Dr. Kolbe* has obtained in the electrolysis of acetic butyric and valeric acids. In subjecting the potassa-salts of these acids to the current he formed among other products the compounds Methyl w% Propyl C,H Butyl (Valyl) . C H which he considers as the radicals of methylic propylic and butylic (valylic) alcohols.Several analogous substances such as ethyl and amyl having lately been obtained by Dr. Frankland? in a totally different mode of decomposition from actual alcohol-compounds it appeared of some interest to extend the galvanic process to a case which would yield a product previously formed by the chemical method. For this purpose we have studied the action of the pile upon caproic acid whose decomposition promised to furnish the compound amyl C1 Hllr previously obtained by Dr. Frankland$ from iodide of amyl. The apparatus used in the decomposition of caproate of potassa prepared from pure caproic acid boiling at 1984 was perfectly similar to that minutely described in Dr. Kolbe's memoir. When six of Bun sen's zinco-carbon elements were employed the decompo- sition of the concentrated solution of caproate of potassa succeeded without difficulty.The liquid rapidly assumed a milky appearance from the separation of numerous gas bubbles and small oily droplets which gradually collected as a layer of oil upon the surface of the liquid contained in the decomposition-apparatus. The gases disengaged consisted chiefly of carbonic acid and hydrogen mixed however with it compound imparting to them a peculiar aromatic odour. The oily liquid when separated by means of zb pipette and sub- jected to distillation began to boil between l25O C. (257O F.) and 160'C. (320' F.) It was evident that as was the case in the corre- sponding decomposition of valeric acid this liquid consisted of a variety of products.Only a limited quantity being at our disposal we at once resorted to the process of purification pointed out by Dr. Kolbe. * Chem. SOC. Mem.111,318. $ Chem. SOC.&ti. 3. 111 262 $ Chem,SOC. &a. J.I11,30. ON CAPROTC AND CENANTHYLTC ACID. For this purpose the liquid was distilled with an alcoholic solution of potassa when a potassa-salt remained in the retort which on addition of a mineral acid yielded an oily acid Although we have not made an analysis of this substance we have no doubt that it was caproic acid; we may here adduce the analogous formation of the acids both in the Valerie as stated by Dr. Kolbe and in the cenanthylic series as proved by our own experiments detailed hereafter. The alcoholic distillate yielded with water a light aromatic liquid which was separated by a tap-funnel and dried over chloride of cal-cium.When subjected to ebullition it commenced boiling at 150° C. (302OF.) the boiling-point becoming stationary at 155O C. (311OF.) when a fraction was collected separately. At 160°C. (320OF.) every drop had passed over. The liquid distilling at 155O possessed all the properties assigned by Frankland to the compound obtained in thed decomposition of iodide of amyl by metallic zinc. When subjected to combustion with prot-oxide of copper the fol-lowing numbers were obtained I. 0.1996 grms. of substance gave 0.6171 , , carbonic acid,* 11. 0.2130 , , substance gave 0.6579 , , carbonic acid and 0.3010 ,) )) water.Percentage-composition I. 11. Carbon Hydrogen . . 84-32- 84.23 15.10 These numbers correspond closely with the formulae c,,HI Or (320 H221 as may be seen from the following comparison The0ry. Mean of Experiment -lOeqs of Carbon . . 60 8450 84.26 a 11. , , Hydrogen 11 15.50 15*70 1 eq. , Amy1 . . 71 100.00 99.96 These results leave no doubt that the substances obtained in the electrolysis of caproic acid and in the decomposition of iodide of * Hydrogen lost 224 MESSRS. BRAZIER AND GOSSLETH amyl are identical ;and hence we may assume generally that the action of zinc upon an alcohol-iodide (C I,) arid the electro- lysis of an acid C(n+ztH(n+z)0, give rise to the formation of the same compound. The products collected above and below amyl contain other products besides amyl; but we are not at present in posses-sion of suiiicient data to form a correct idea respecting the na-ture of these substances.From the analogous observations of Dr. Kolbe in the valeric series we should expect to meet in the lower fraction the hydrocarbon C, H, and fusel-oil arising from the decomposition of the compound ether C, Hll. C, HII 0 by the contact of the crude oil with potassa. We have not as yet studied this question with sufficient accuracy; but it may be even now stated that in the lower fraction we have not up to the present moment been able to detect fusel-oil. Moreover the existence of an ether C, Hll. C, H, 0, in the crude product of the electrolysis ,is not supported by the results of observation for this compound ether which would be nothing else than the caproate of amyl prepared by us as stated above boils at 211O C.(411°%F.) whilst the crudc product entirely distilled below 180°C. (356O F.) However we leave this question open and are satisfied to have established by experi- ment the analogy of the principal metamorphosis of valeric and cnproic acids under the influence of the galvanic current. DECOMPOSITION OF CENANTHYLIC ACID UNDER THE INFLUENCE OF THE GALVANIC CURRENT. Incidentally to the experiment with caproic acid we have also subjected cenanthylic acid to the action of the pile. The acid which served us for the experiments communicated in the remaining portion of our paper was prepared in the manner recommended by Tilley,* by acting upon the oil of Ricinus corn-rnunis with dilute nitric acid.By this means with considerable patience a sufficient amount was obtaiued. We have tried various other processes oxidation of the oil with chromic acid or a mixture of bichromate of potassa with sulphuric acid or treatment of ananthale with various oxidizing agents ; but we have invariably found that the action of nitric acid on the oil although tedious in the extreme still gives the best results. The crude acid was repeatedly washed and afterwards redistilled with water in order to ensure its perfect purity. As it is partially decomposed by distillation alone * Cbem .Soc.Mem. I. O?$ CAPROIC AND CEXANTHYLIC ACID. we tested its purity by the analysis of a silver-salt in preference to taking th e boiling-point.0.2324 grms. of silver-salt gave 0*1052 , , silver yielding a percentage of 45.30 of eilver. Theory requires 45.56 of silver. The potassa-salt was easily made by neutralizing the acid with pure carbonate of potassa. This salt is not crystallizable; it is easily soluble in water. The phenomena observed in the decomposition of aenanthylic acid are perfectly analogous to those exhibited in the electrolysis of caproic and valeric acid,-evolution of carbonic acid and hydrogen sepa-ration of an oily layer in the decomposing apparatus and formation of carbonate and bicarbonate of potassa in the residuary aqueous solution. The oily layer which had an ethereal odour and a sweetish taste was separated dried and subjected to distillatioii.]It boiled between 230° (266OF.) and 230° (446OF.) the thermometer exhi- biting a tendency to become stationary towards 190° (374O F.) Near the close of the operation the liquid assumed a dark-brown colour and a considerable quantity of charcoal remained in the retort. The separation of the various constituents of the oil was effected by treat-ment with an alcoholic solution of potassa exactly as in the product obtained from caproic acid. However as we performed these experiments upon a somewhat larger scale we took care to establish by analysis the nature of the acid remaining in form of a potassa-salt. For this purpose the acid was separated by hydrochloric acid washed converted into the ammonia-salt and subsequently into the silver-salt.0.4965 grm. of silver-salt gave 0-2260 , , silver == 45.51 per cent Theory requires 45.56 per cent. These numbers establish beyond doubt the separation of anan-thylic acid by potassa from the crude-oil product. The alcoholic distillate when treated with water yielded an oily liquid which after being dried with chloride of calcium boiled between 170° (338O F.) and 210° (410° F.) ; by far the largest quantity how-ever distilled at 202O (395*6Ol!.) In fact the thermometer became stationary at this temperature even in the first rectification. The fraction collected round this point n hen distilled once more exhi-VOL. III.-~O. XI. a MESSRS* BRAZIER AND GOSSLETH bited a perfectly constant boiling-point at 20.2' (395.6 F-) This liquid had a very agreeable aromatic odour it was insoluble in water but miscible in all proportions with alcohol and ether Analysis gave the following results I.0.2245 grins. of substance gave 0.6940 , , carbonic acid and 0.3160 , , water. 11 0.3345 , , substance gave 1.0370 , , carbonic acid and 0*4650 , , water. Percentage-composition I. 11 Carbon . . 84.49 8454 Hydrogen . . 15.60 15*44 These numbers correspond closely with the formulze clz HH13 Or c24 H26 as may be seen from the following comparison Theory. Mean of experiment. -12 eqs. of Carbon * . 72 84-70 84.52 13 , , Hydrogen 13 15.30 15.52 1 ,* , Caproyl . . 85 100.00 The formula C, HIS,homologous to those of methyl ethyl &c.would represent the radical of an alcohol C, H, 0, standing to caproic acid in the same relation as acetic acid stands to wine- alcohol. This alcohol might be termed caproylic alcohol and the corresponding radical hydrocarbon caproyl. The nomenclature of this series is so sadly embarrassed by the accdmulation of similar names in the eighth and tenth family that-objectionable though the rechristening of chemical compounds may be-we believe that the suggestion of more appropriate names for caprylic and capric acids would meet the general approbation of chemists. It would have given us much pleasure to have studied the deport- ment of caproyl under the influence of re-agents the more so as the pinions of chemists are divided respecting the formuk of the so-called radicals some of them adopting expressions corresponding to 2 volumes of vapour others preferring 4 volumes in a formulz.The study of the products of decomposition of caproyl might have decided this question ; bnt unfortunately the limited quantity of substance at our chsposal ON CAPROIC AND (ENANTHYLIC ACID prevented us from following out this direction of the enquiry. Moreover caproyl exhibits but little disposition to furnish readily accessible products,* We mention only that the substance is not affected by concentrated sulphuric acid and that it may be distilled with moderately coneen- trated iiitric acid without undergoing any change It was only by distillation with a mixture of the two acids that a very slow and evcn then incomplete oxidation took place.After repeated dis-tillation the distillate was mixed with water ;the supernatant oil separated by a pipette and heated with ammonia dissolved but partially. The amnioniacal solution contained an oily acid which separated on addition of a miiieral acid and exhibited the odour of caproic acid. We converted the remaining solution after boiling off the excess of ammonia into a silver-salt which was deposited as a whitish very difficultly soluble powder. After recrystallization it was obtained in slightly yellow crystals which gave on analysis the following results I. 0-2145grm. of silver-salt. gave 0.1055 , ,,silver. A second specimen prepared in a similar manner was analysed in the same way; during ignition a slight deflagration took place.11. 0.1486 grrn of silver-salt gave 0*(3686 ) ),silver Percentage 1. 11. Silver . . 4913 46.16 The theoretical percentage of silver in the caproate is 48.65 and in the nitrocaproate 40.30; the first analysis exhibits a slight excess which may be clue to reduction of a small quantity of silver during the recrystallization of this rather difficultly soluble salt. The deficiency of the secoud may possibly be owing to the presence of a * The remarkable unalterability of the so-called radicals when contrasted with the want of stability of the higher homologues of marsh-gas-as indicated by the non-production of these substances in the reaction of alkaline earths upon the higher terms of the series C H 0,-appear to discountenance more and more the assumptions of the identity of the two classes of compounds.As I had an opportunity of suggesting at an earlier period (Chem. SOC. Qu. J. 111 133) the radicals may be only isomeric bith the marsh-gas series. This of course does not interfere in the slighest degree vith the adoption of 4 volume formulze; nor does the conversion of coproyl into caproic acid which 1 consider established by the experiments of hlessrs. Brazier and Gossleth in my opinion militate in the slightest degree against the admission of the higher forinula+-A. W. H. QfL MESSRS. BRAZIElt ASD GOSSLETH small quantity of nitrocaproic acid a supposition which is supported by thc slight defiagration during combustion and by an analogous observation of Dr.I<olbe,* in the oxidation of butyl. We are sorry that our results are not more definite but hope their insufficiency will be excused by the difficulty attending these operations. We have no doubt in our own miads that the acid produced under these circumstances is caproic acid. Bromine has scarcely any action upon caproyl not even under solar irradiation. Chlorine acts very powerfulIy even in diffused day-light torrents of hydrochloric acid being immediate!p disengaged. The caproyl is rapidly converted into a viscous mass which being decomposcd on ebullition with evolution of hydrochloric acid and deposition of carbon codd not be purified for analysis. Even by a very moderate action of chlorine me did not succeed in obtaining a direct compound of caproyl with chlorine.In conclusioa we have to add thnt we have made 8few experiments with tlic oil which pasesd over before caproyl in the rectification of the liquid separated from the alcoholic distillate after treatment with potassa. This substance which has an aromatic odour and sweet taste was several times redistilled &hen a compound mas obtained boiling pretty constantly at 175O (347' F.) Analysis with protoxide of cop- per gave the following results 0.3220 grm. of substance gave 1*0070 ?, ,,carbonic acid and 0.4225 , water Percentage-composition. Theoretical values of C H,. Carbon . . 85.29 Carbon . . . 85.72 Hydrogen 14-57 Hydrogen . 14.28 These numbers show that the liquid in question is a hydrocarbon of the family C H, the slight deficiency in the carbon and the excess in the hydrogen being evidently due to the presence of a trifling quantity of caproyl We have no direct data for the value of n ;the boiling-tempera- ture would point to the formula C We have not met among the products obtained in the electrolysis of cenanthylic acid with the hydrocarbon caproylene (oleylene) C, 1Il2 or with caproylic alcohol the formation of which substance we might have expected from the analogous deportment of valeric * Chem SOC.Qu. J. 11 163 ON CAPICOIC AND CENANTHYLIC ACID. acid; we cannot however adduce any positive evidence as to the absence of small quantities of these substances.The question what compound in the crude oil gives rise to the formation of the Enan-thylic acid whether it be a kind of compound ether or an aldehyde &c. has still to be answered by furthcr experiments. One point however appears to be fixed by the preceding expe- riments namely that the members of the series C Hn 0, when treated with the galvanic current invariably give rise to the forma- tion of a hydrocarbon closely connected with the series following one step lower on the scale of organic compounds hydrosen and carbonic acid being simultaneously eiiininated. Generally expressed this metamorphosis would be represeated by the following equation C Hn 0,+ HO = Cfn-2) H(n-1) + HO + 2 CO + He This equation shows that formic acid when esposeil to the current can yield only hydrogen and carbonic acid.Together with this prin- cipal metamorphosis several secondary changes appear also to occur whose nature however is not yet perfectly understood. It deserves moreover to be noticed that these lattcr changes far from presenting the constant character of the chief decomposition appear to vary with the position of the eubstances examined upon the ladder of combustion.

ISSN:1743-6893    

DOI:10.1039/QJ8510300210

出版商:RSC    

年代:1851

数据来源: RSC

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ON CAPICOIC AND CENANTHYLIC ACID. XXIV.-Creutine a constituent of the Flesh of the Cetacea BYDAVIDS. PRICE,Ph. I). A fine specimen of the Rorqual Whale (Bala?nopteramusculiis) having been brought into Rlargate in February last I availed myself of the opportunity afforded of ascertaining whether creatine which has been found to be a constituent of the rnuscIes of various mani- rnals birds and fishes was likewise contained in those of the cetacea. It has been shown by Liebig that the muscles of fat animals yicld a much smaller quantity of this substance than those of lean oiies; and as the whale may be ranked pre-eminently among the former it was deemed necessary in ordcr to ensure a decided result that a large quantity of the flesh should be employed.For this purpose about 40 lbs. the freest from fat that could be selected were treated in the manner described by TAiebig in his research into the constituents of the juices of the flesh; 10 lbs. of the flesh were cut into small pieces and well kneaded with an equal weight of cold water. The DR PRICE ON CREATINE IN THE flesh was then removed to another vesrel holding the same amount of water and after being again well pressed was put in linen bags into a strong screw-press and as much of the liquor obtained as possible; the second water served as the first receptacle for another 10 lbs. of flesh which were treated in like manner &c. In this way the extract from the 40 lbs. was eventually obtained. The large quantity of fat which collected on the surface of the fluid had to be removed prior to the liquid being strained through flannel bags for the purpose of separating any muscular fibre and fatty matter that might be suspended in it.The filtered liquid which was of a blood colour and exhibited an acid reaction was heated in large evaporating pans over a water bath whereby the albumen was coagulated taking with it nearly the whole of the colouring matter the liquid on being strained through linen bags retaining only a very faint colour. The odour and flavour of this filtrate was not distinguishable from that of the extract of beef. In order to separate the last traces of albumen the liquid extract was rapidly heated to ebullition over a strong fire in a tinned copper vessel.After being filtered the solution was mixed with concentrated baryta-water till a precipitate ceased to be formed a point which was reached long after the acid reaction had disappeared. The almost colourless filtrate when evaporated in the water bath acquired a dark brown eolour and became gradually gelatinous emitting an odour very similar to that of glue. The concentrated liquor was now placed in a cool situation in several shallow vessels when after the lapse of forty-eight hours numerous minute glittering crystals were deposited which owing to their great specific gravity could be easily separated by decantation of the supernatant liquid. When dried in this minute state these crystals presented a beautiful appearance refracting light with remarkable intensity.After three or four crystallizations they may be obtained quite pure. If their aqueous solution be allowed to crystallize slowly crystals one quarter of an inch in length are formed presenting a silky lustre and frequently arranged in groups. These crystals are insoluble in alcohol but very soluble in boiling water; when warmed on platinum foil they lose their lustre becoming opaque and white; when heated more strongly they carbonize emitting the odour of burning nitrogenous substances ; on the application of a still stronger heat the carbon is entirely consumed no ash remaining behind. 0.30537 grms. of this substance when kept for some time in a water bath at a temperature of 212* F, lost 0.0378 grms. FLESH OF THE CETACEA 231 corresponding to 12.2 per cent of water the amount found by Liebig in creatine prepared from different sources. I must not forget to state that I obtained this substance (a specimen of which I have the honour to lay before the Society) in very small quantity. There can be no doubt as to the identity of this body with that described by Chevreul Liebig Schlossberger and Gregory; and we may safely conclude that it is a constituent in greater or less amount of the fluids Iof the flesh of all the higher class of animals.

ISSN:1743-6893    

DOI:10.1039/QJ8510300229

出版商:RSC    

年代:1851

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FLESH OF THE CETACEAo XXV,-Researches on the Volatile Organic Bases. BY DR.A. W. HOFMANN. VIII ON THE BEHAVIOUR OF ANILINE AND THE ALCOHOL-BASES WITH NITROUS ACID.* Chemists are acquainted with the happy idea which led Piria? to examine the deportment of substances derived from ammonia under the influence of nitrous acid. The property possessed by nitrous acid of being reduced by ammonia with evolution of nitrogen ap- peared likely to afford a simple method of effecting a regular oxida- tion of the derivatives of ammonia or in other words of reconverting an amide into an oxide. N H3 + NO = 2N + 3H0, N H,X + NO = 2 N + 2 HO + XO Piria has proved by experiment that oxamide suceinamide and butyramide when treated with nitrous acid are readily reconverted into the corresponding acids nitrogen being evolved.He succeeded moreover by the aid of this process in establishing the true character of two substances asparagine and aspartic acid which have henceforth to be considered as malamide and malamic acid. At a later period the same reaction was applied to several nitroge- nous compounds of uncertain constitution by M. Strecker.f This chemist found that hippuric acid glycocine and leuciiie when treated with nitrous acid exhibit a perfectly analogous deportment the former yielding an acid C, H O, the two latter terms of avery remarkable series of acids C H O, parallel as it would appear with the series of fatty acids. * The former papers belonging to this series have been published. Chem. SOC.Qu. J. I 159 269 285; 11 36 300. t Ann. Chim. Phys. [S] XXII 160. $ Ann Ch. Pharm. LXVIII 55. 232 DR. HOP’MANN ON THE Among the various clasw of nitrogenous substances there is pcrhaps none which is likely to derive more benefit from this reaction than the group of organic bases. Connected as these substances arc with ammonia by ties of greater or less intimacy the observation of their deportment under the influence of this agent opens a field of investigation which up to the present moment has scarcely been entered upon. The only base hitherto investigated in this direction is aniline. Some experiments on the behaviour of this alkaloid have been corn-municated by Mr. T. s. Hunt,* who found that this substance when exposed to the action of nitrous acid is converted into phenole nitrogen being evolved.-N H (GI H,) + NO = C, H 0. HO + HO + 2 N. v Aniline. Phenole. This decomposition is quite in accordance both with the results obtained in the metamorphosis of other substances by Piria and Strecker and with the close relation existing between aniline and phenole-a relation which has been remarkably illustrated by the study of the derivatives of the two substances. Aniline when treated with nitric acid yields trinitrophenole whilst chlorine gives rise to the formation of trichlorophenole ; both aniline and phenole when subjected to the action of chlorate of potasea and hydrochloric acid are converted into chlorokinone (chloranile) . Experiment moreover has shown that phenole may actually be converted into aniline by exposure to the influence of ammonia at high temperatures.The position therefore of aniline as a member of the phenyl-group scarcely required the additional support of its reconversion into phenole. Still experimentally this conversion offers con-siderable interest inasmuch as it shows that this siniple process admits of eliminating the nitrogen from compounds which are capable of resisting the most powerful agents at our disposal. It is well known that the vapour of aniline may be passed over ignited soda- lime without undergoing decomposition and that we are consequently obliged to introduce certain modificationst into the ordinary process for the determination of nitrogen. The interest of the subject and moreover the fact of Mr.Hunt’s investigation being entirely qualitative induced rne to repeat his experiment with the view of proving the relation existing between aniline and phenole by definite numbers. * Sill. Am. S.Nov. 1849. * Chem. SOC.Qu. J. I 159. VOLATILE ORGANIC BASES. Mr. Hunt has performed the experiment in two different ways namely 1. By exposing a mixture of the base with nitric acid of a given strength to the action of binoxide of nitrogen as originally proposed by Piria.-Z. By acting upon hydrochlorate of aniline with solution of nitrite of silver. He obtained by both methods a dark-brown oil soluble in potassa possessing the odour of castoreum and an acrid taste and yielding with nitric acid nitrophenisic acid (trinitro- phenole) .By following the former of the two processes adopting exactIy the circumstances and proportions indicated I never succeeded in ob- taining a substance from aniline which I could with certainty have declared to be phenole. Invariably a dark-brown resinous mass was formed which indeed had the odour of castoreum and was soluble in a great excess of potassa but from which no phenole in a state of purity could be obtained. Nor was the experiment attended with better results when the circumstances mere slightly modified by substituting a weaker or a stronger acid I found that either no action at all took place or the metamorphosis went too far the aniline being converted into the brownish resinous mass. This mass may contain traces of phenole but it consists chiefly of a brown uncrystallizable substance together with a crystalline compound of most remarkable beauty which I subsequently obtained in larger quantity when acting upon aniline with a mixture of nitric and arsenious acid from which I had anti- cipated a result analogous to that obtained by Mr.Millon in the preparation of chlorous acid. This substance is nitrophenole which may be likewise obtained by acting with dilute nitric acid upon phenole itself. The study of' this compound which furnishes several links of connection between the phenole-family and various other groups will be the subject of another communication to the So. ciety. The presence of free nitric acid interfering sadly with the conversion of aniline into normal phenole yielding as it does according to the concentration of the acid products derived from this compound by a more or less advanced substitution ; I availed myself of the second process namely decomposition of the hydrochlorate of aniline with nitrite of silver.This experiment yielded a totally different result. As soon as the two substances come into contact torrents of pure nitrogen gas are evolved the whole liquid becomes turbid from the 234 DR HOFMANN ON THE separation of oily globules which are likewise of a very dark colour from which however pure yhenole may be prepared without much difficulty. When separated from the liquid by means of ether and subjected after the removal of the ether by evaporation to distillation with water they yield a quantity of a perfectly colourless oil ; but even in this process a considerable portion of resinous substances is pro-duced The oil separated from the water and rectified over an-hydrous phosphoric acid passed over in the form of a limpid liquid which solidified after a short time into a mass of white crystals possessing all the properties of phenole Analysis with protoxide of copper gave the following results 0*3080grms.of crystal gave 0.8605 , , carbonic acid and 0*1780 , , water. These numbers lead to the percentage which I subjoin to the values required by the formula c, H 025 Theory. Experiment. * 1.2 equivs of Carbon . 72 76.50 76.22 6 , , Hydrogen 6 6.38 6.38 2 )t Oxygen 16 17-02 --I_____ I 39 , Phenole .. 94 100.00 These numbers leave no doubt respecting the transformation of aniline into phenole by the action of nitrous acid. The method of employing the nitrous acid in form of a silver-salt or as I have invariably done in subsequent experiments in the form of a potassa-salt,* eliminates in a happy manner the difficulties attending the use of so powerful an agent as nitric acid under whose influence agreat many substances would uudergo further transformations. The conversion of aniline into phenole by this method renders it probable that the derivatives of aniline the anilides will admit of similar transformations. The action of nitrous acid would thus afford a general passage from the anilides to the phenides.Carbanilic acid would in this manner yield salicylic acid (carbophe- nylic acid) oxanilic acid might be converted into phtalic acid (oxaphenylic acid) relations of these acids with the aniline-series * The crude nitrite containing free potassa together with undecomposed uitrate as obtained by decomposing nitre may be employed with perfect success. VOLATILE ORGANIC BABEEL being undeniable the former passing into aniline through phenole the latter through benzole. C, H N + NO3 = C1 H6 0,4-HO + 2N U + Aniline. Phenole. C14 H N 0 + NO = C14H 06 + HO $. 2N -Y---J + Carbanilic acid. Salicylic acid. C, H N 0,+ NO = c16 H 0 + HO + 2N, + + Oxanilic acid. Phtalic acid. Whether the anilides are actually affected by nitrous acid and whether if such be the case the products formed are identical or isomeric with the substances which theory appears to suggest has to be decided by further experiments.The facility with which aniline is converted into phenole standing to it in the position of an alcohol induced me to perform some corresponding experiments with the bases of the series C H (n+3) N. This series attracted my attention particularly since it is at present much more complete than the series of collateral alcohols C 0 as seen from the following conspectus Methylic alcohol . C H 0 Methylamine C H N Ethylic alcohol C H 0 Ethylamine C H N. Propylic alcohol ? Propylamine . . C €1 N. Butylic alcohol . ? Butylamine . . C H, N. Amylic alcohol .C, H, 0 Aniylamine . C, Hi3 N. Whilst methylamine ethylamine and amylamine have been formed with the assistance of the alcohols themselves propylamine (cenylamine metacetamine) and butylamine (petinine) have been derived from sources perfectly unconnected with alcohols the former being produced according to W ertheim,* from narcotine by the action of alkalies whilst the latter was found by Anderson? amongst the products of distillation of animal substances. A deport-ment of this series with nitrous acid analogous to that exhibited by aniline would have put us in the possession of the missing alcohols. The change which these substances undergo is not perfectly similar to that of aniline. The first experiments which I performed were made with ethylamine.On distilling a mixture of hydrochlorate of ethylamine with either nitrite of silver or nitrite of potassa a violent effervescence of nitrogen took place and an aqueous liquid * Ann. Ch. Pharm. LXXIII 208. -f Phi& Mag.[3] XXXIII,174. DR HOPMANN ON THE passed over which contained no alcohol or mere trcces of it whilst a yellowish oil of a penetrating aramatic odour and a sweet but pun- gent taste floated on thc surface. The amount of this oily liquid- which had rather a higli boiling-point-being quite out of proportion with the quantity of ethylamine employed I was led to subject the gas evolved to a closer examination. I found that this gas was inflammable burning with the green- edged flame of nitrous ether that it dissolved partly in water yielding a solution in which the presence of nitrous acid could be ascertained by sulphuric acid and green vitriol aid from which the gas could be expelled again by heat.The experiment being pcr-formed during hot weather I endeavoured to condense the ether by passing the disengaged gas through a glass serpentine placed in a frigorific mixture I did not succeed however in collecting the liquid ether. This compound is diffused in so bulky a volume of nitrogen that its condensation would require both the employment of a larger quantity of ethylamine than 1 had at my disposal and the use of more efficient refrigeration and perhaps even preliminary absorption of the ether-compound in alcohol. However be this as it may the action of nitrous acid upon ethylamine gives rise to the formation of a cortsiderable quantity of nitrous ether other sub- stances being formed at the saine time.The conversion of ethylamine into nitrite of ethyl requiring two equivalents of nitrous acid C,EI,N + 2NOs = C4H,N0,+-2HO -j-2N, + + Ethylauiine. Nitrous ether. it appeared that the production of the latter might be greatly facili- tated by the action of the nitrite upon an acid solution of the base. Experiment has borne out this anticipation. In fact it suffices to throw into a solution of hydrochlorate of ethylamine mixed with its own bulk of hydrochloric acid a crystal of nitrite of potzssa when at once together with nitrogen nitrous ether is evolved in consider- able quantity the vapour of' which may be lighted at the mouth of the test-tube.In this manner the conversion can be readily exhi- bited in a lecture-experiment. The yellow aromatic oil which is formed together with the nitrous ether and the production of which I must add is not prevented by the use of an acid solution is obtained in so limited a quantity that f have not yet been able to subject it to a closer examination attractive though the study of a substance produced under so peculiar circumstances must be. I would not have dared toaffirm on the ground of the experiments VOLATILE ORGANIC BASES. detailed the generation of nitrous ether in the above reaction had I not acquired additional support for this position by repeating the same experiment in a less volatile series oxupging a higher position in the system.In their researches on caproic acid Messrs. Brazier and Gossleth bad obtained a considerable quantity of amylamine as a secondary product which these gentlemen kindly placed at my disposal for the experimeiit. Hydrochlorate of amylamine when submitted to the action of a nitrite exhibits exactly the same deportment as ethyla-mine. The experiment is best performed by heating a sclution of nitrite of potassa in a flask connected with a condemer and adding the solution of hydrochlorate of amylamine acidified with hydro-chloric acid in small portions through a funnel-tube the violent effervescence produced upon each addtion being allowed to subside before pouring in a new quantity. By this means an aqueous distillate is obtained with a yellowish oily layer floating upon its surface cxhibitiiig in a remarkable manner the peculiar odour of nitrite of arnyl which for the sake of comparison had been prepared from fusel-oil.The oily substance being separated by means of a pipette the aqueous liquid yielded a little more by saturation with common salt. The whole quantity of oil obtained in this manner amounted to about 4th of an ounce. When dried and sub- jected to distillation the thermometer showed that it was a mixture ebullition commencing at about 90° the thermometer rising slowly to about 1104 and then gradually to 2004 a small quantity of carbon remaining in the retort. During the first part of the distillation a perceptible evolution of red vapours took place evidently arising from the partial decomposition of the nitrite of amyl.A comparative experiment with nitrite of amyl prepared from fusel-oil yielded the same result. The fraction collected between 90° and llO0 when re- distilled exhibited a tendency towards a constant boiling-point a little below looo. The thermometer however rose to nearly 17O0 towards the close of the operation showing that the nitrite of nmyl still con- tained a considerable quantity of other substances. Lest too much should be lost by further rectification the portion collected just below looowas subjected to combustion. 0.3110 of oil gave 0.6125 , carbonic acid and 0.2900 , water. Percentage Carbon . . 53.7; Hydrogen . . . . . 10.36 238 DR.HOFMANN ON THE The formula c,o Hw N 0, requires Carbon . . . . . . 51.21 Hydrogen . . . . 9.41 These numbers showed that the nitrite under examination was still mixed with a quantity of a substance containing more carbon and hydrogen. The boiling-point of pure nitrite of amyl according to Ba1 ar d’s experiment is 96O. Not satisfied with these approximate numbers I endeavoured to obtain additional evidence by the conversion of the nitrite into fusel- oil. After having established by experiment that nitrite of atnyl like its houiologue in the ethyl-series when treated with hydrosul- phate of sulphide of potassium gives rise to the formation of the correlative alcohol with formation of an alkaline polysulphide and ammonia according to the formula C, H, NO + 6NS = C, H, 0 + NH + 2 NO + 6 S.u + Nitrite of amyl. Amyl-alcohol. I subjected the impure nitrite to the same treatment. A violent reaction took place in which the separation of ammonia and sulphur could be traced without difsculty. The resulting fusel-oil at once evident by its nauseous odour was moreover converted into sulphamylic acid by dissolving it in sulphuric acid (when a small quantity of the aromatic oil remained uncombined) and subsequently transformed into a baryta-salt. These experiments leave no doubt respecting the formation of nitrite of amyl by the action of nitrous acid upon arnylamine. In the same reaction however other substances are formed; I say sub- stances because the aromatic oil which boils at the higher tempe- rature when allowed to stand gradually deposits a quantity of shining crystals having a greasy appearance.The same substance which is extremely fusible is usually found to separate on the addition of water to the residue of chloride of potassium in the decomposing flask. I have up to the present moment not the slightest notion respecting the nature of these compounds. Although the difficulty of perfecting these reactions appears at present altogether to preclude the possibility of arriving at the practical formation of propylic and butylic alcohols I was never-theless desirous to see whether propylamine and butylamine would exhibit a similar deportment with nitrites. For this purpose I prepared a quantity of propylamine according VOLATILE ORGANIC BASES.to the directions given by TVertheim by distilling narcotine with an excess of hydrate of potassa.* The aqueous solution of pro-pylamine when supersaturated with hydrochloric acid and treated with nitrate of potassa gave rise to a powerful evolution of nitrogen accompanied by an inflammable gas burning with a green-edged flame. Accordingly propylamine eshibits with nitrous acid a de-portment similar to that of ethylamine; and from analogy we may infer that the burning substance was the nitrous ether of propylic alcohol or nitrite of propyl C H,. N 0,. I am indebted to the kindness of Dr. Anderson of Edinburgh for a small quantity of butylamine prepared by him from Dippel's oil. When dissolved in hydrochloric acid and treated with the nitrite this base likewise evolved a considerable quantity of nitro- gen but no inflammable vapour.The latter circumstance is readily intelligible if we recollect that nitrite of butyl would boil at a rather high temperature at about SO0 a temperature high enough to prevent the compound from evaporating in sufficient quantity in the gas evolved. When the operation was performed in a small retort the evolution of nitrogen was attended with the separation of small oily globules which floated upon the water running down the condenser ; but were dissolved again before reaching the receiver in which an aqueous liquid of a very peculiar odour was collected. Analogy allows us to infer that in this reaction nitrate of butyl C H N 0 the nitrous ether of the butyl-series is formed The regeneration of the alcohols from the nitrites by means of hydrosulphuric acid having been established by experiment it is evident that the deportment of propylamine and butylainine with nitrous acid may one day become the key to the formation of their collateral alcohols as soon as the progress of science shall have taught us simpler and more abundant sources of these bases.In conclusion I wish to draw the attention of the Society to the light which the preceding experiments appear to throw upon some earlier investigations. In 1845 M. Gerhardt observed that the action of nitric acid upon brucine gives rise to the evolution of a gas which burns with a green flame and exhibits some of the properties of nitrous ether.The formation of this ether in the process alluded to was subsequently * By the distillation of narcotine with potassa in addition to an aqueous solution of propylamine an oily base boiling apparently at a very high temperature was formed which deserves to be examined. The odour of propylamine remarkably resembles that of lobster in an early stage of putrefaction. 240 AI. CA'LHOUItS ON doubted by Liebig who on repeating the experiment obtained a liquid boiling at a temperature (from 70° to 7P),much higher than the boi1ing:point of nitrous ether (16O.5). It is evident that the action of nitric acid upon brucine induces the formation of various substances. The existence among the natural alkaloids of ettiylated bases which I suggested on a former occasion and which appears to be borne out by new facts such as the formation of methylinline from caffeine or of propylamine from narcotine renders it probable that part of the metamorphosis caused by nitric acid is due to the formation of nitrous acid which subsequently acts as in the foregoing experiments I have distilled an acid solution of hydrochlorate of brucine with nitrite of potassa and find that this reaction gives rise to the evolution of a considerable quantity of the inflammable gas burning with a green-edged flame which is obtained by directly dissolviiig bruciiie in nitric acid.

ISSN:1743-6893    

DOI:10.1039/QJ8510300231

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年代:1851

数据来源: RSC

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240 XXVL-Researches on Pelargonic Acid. BY M. AUGUSTECAHOURS. (LETTER TO DR. A. w. HOFMANN.) The action of nitric acid on the essential oil of rue gives rise to several homologous acids. The first term of this series to which I have given the name Rutic acid only differs from the oil itself by containing two equivalents of oxygen more the latter stands therefore to the former in the relation of an aldehyde. The action of nitric acid however is not confined to a simple oxidation of the essential oil; according to the duration of the action (C H,) 2(C H,) 3(C H,) are successively oxidized,-pelargonic caprylic and cenanthylic acids and probably other more simple terms of the same series being formed. It is evident that in employing com- mercial acid and allowing it to act for some time on the oil several of these products are finally obtained the one predomi-nating over the others according to the duration of the reaction.Pelargonic acid being the one least known of this group and being also obtained the most plentifully from oil of rue I turned my attention to it in preference; its study has furnished me with the following results Pure pelargonic acid is colourless assuming an amber tint after a time. It boils steadily at 260*,and distils without undergoing alteration or change of colour ii the precaution be taken to perform PELARGONIC ACID. the distillation in an atmosphere of carbonic acid. The analysis of several specimens has furnished me with numbers leading to the formula CIS Hl 0,.This acid forms soluble and crystallizable salts with potassa soda and ammonia. With baryta and strontia it yields salts slightly soluble in water and soluble in boiling alcohol from which solu- tion they separate on cooling in the form of crystalline scales of nacreous appearance. The analysis of these salts led to the formulre RaO. C, Hi7 0 CaQ. C, H, 0,. If a current of hydrochloric acid gas be passed into an alcoholic solution of pelargonic acid an amber-coloured oil soon separates and floats on the surface ;this oil treated with a solution of carbonate of soda washed with pure water dried over chloride of calcium and distilled is obtained as a colourless liquid the density of which is 0.86; its boiling-point is between 216O and 218O.The analysis of this product led to the formula c22 H22 04 = (34 H 0.c, II, 0,. On ebullition with a concentrated solution of caustic potassa alcohol and pelargonic acid are reproduced. Pentachloride of phosphorus acts very violently on pelargonic acid hydrochloric acid gas being abundantly evolved ; if the experi- ment be performed in a distilling apparatus a colourless liinpid distillate is obtained which contains a large quantity of oxychloride of phosphorus ;on re-distilling this product and rejecting the portion which passes over before the temperature becomes stationary a limpid liquid is obtained as the latter portion of the distillate which is heavier than water and boils at 220°. This liquid which gives OR dense fumes when exposed to the air and has a veyy powerful odour evolves much heat when brought in contact with alcohol pelargonic ether being formed.The analysis of this product led to the formula CIS HI7 c10,* It is therefore the Chloride of PeZargyZ. Pelargonate of baryta is decomposed by dry distillation il residue of caybonate of baryta being obtained a brownish oil collecting in the receiver which solidifies on cooling. This substance when pressed between bibulous paper yields a solid product easily soluble in ether. The ethereal solution submitted to spontaneous VOL. IIIo-NO XI. R 242 M CAHOTJRS ON evaporation deposits large crystalline plates assuming a nacreous appearance on desiccation This product submitted to analysis yielded numbers coinciding with the formula c34 H34 0,.This substance is therefore PeZargone isomeric with margaric alde- hyde. Its formation is explained by the following equation 2 (BaO. C, HI 0,) = 2 (BaO. CO,) -I-C H3 0,. Pelargone is violently attacked by fuming nitric acid a nitrogenous acid being formed which is doubtless a homologue of that obtained by the similar treatment of butyrone If we assume that the action of an excess of alkaline base at a high temperature on the acids of the acetic series give rise to phenomena similar to those observed with benzoic acid or acetic acid itself we should expect to obtain by the distillation of pelargonic acid with an excess of potash-lime either the valyl of Kolbe or a compound isomeric with it; this presumption is not however confirmed by experiment.On submitting a mixture of pelargonic acid with from four to five times its weight of potash-lime to a temperature nearly approaching a dull red-heat a large quantity of gas is disengaged some volatile products are condensed and a residue of partially carbonated alkali is obtained. On passing the gas into bromine a portion is absorbed and the rest passes through unaltered. The portion absorbed by the bromine forms with this substance a very dense liquid which when treated with a very weak solution of potassa in order to remove the excess of bromine yields an amber-coloured heavy liquid consisting of three different substances; the one boils at 130° and crystallizes when the vessel containing it is immersed into powdered ice this is Dibromo-mylene C4 H Br,; the second boils at 143' to 144O and is the Dibromo-propylene C €1 Br ; the third which boils at 160° is Dibronzo-butylene C H Rr,.The first and particularly the latter of these substances are present in very small quantity corn pared to the prop ylene -compound. The liquid product of this reaction is of a complex nature the larger portion boils between 105O and 1loo; the latter portion distils at 136O. Several analyses made with different specimens of the liquid which boiled between 106O and llOo,have given me as a mean 84.9of carbon and 14% of hydrogen that is to say more hydrogen and less carbon than in olefiant gas; the idea naturally suggested itself that this liquid might be a mixture of valyl and of a hydrocarbon of the series PELARGONIC ACID.C H having a very proximate boiling-point ; some experiments however soon convinced me of the absence of valyl this liquid being violently attacked by some reagents that have no action on valyl. The vapour-density of this substance was found to be 3-98,which leads to the formula C, H, = 4 volumes of vapour. This substance therefore would appear to be a hydrocarbon homo-logous to olefiant gas mixed with a small quantity of foreign matter. When treated with bromine it evolves heat yielding a liquid having an aromatic odour. The analysis of this liquid yielded numbers leading to the formula c, HI Br;* The gas which is not acted on by bromine consists of hydrogen and another gas containing carbon which is probably marsh-gas.The deportment of pelargonic acid accordingly differs in this instance essentially from that of its homologue acetic acid; the carbo-hydrogen C16H,, which should be produced in this reaction appears to be possessed of but little stability splitting up as it does into hydrogen and marsh-gas. It is probable that all the acids of the acetic series furnish analogous results. I have convinced myself that this is the case at least with caprylic and mnanthylic acids.* I am just now studying ethalic and margaric acids with the same view.

ISSN:1743-6893    

DOI:10.1039/QJ8510300240

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年代:1851

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PELARGONIC ACID. XXVI.-On the Red Golouring Matters ~fMadder. BY ADOLPHSTRECKER. There is scarcely any class of bodies in organic chemistry the investigation of which is attended with so many diflFiculties as that of the colouring matters; this may account for the imper- fect knowledge we as yet possess of these substances excepting indigo which has been studied in every direction. Of many colouring matters Fe scarcely know more than the existence while of others we possess the percentage-composition translated into a more or less fitting empirical formula; a few only of these sub- stances have become of late so far accessible to us as to enable US to acquire a knowledge of them corresponding to the present demands * The same results are obtained in the distillation 6f ~alericacid.Comp. Chem. Soc. &I J. 111. R2 DR STRECKER ON THE of the science. This circumstance may be owing in some measure to the dificulty experienced in obtaining these substances in quan- tity sufficient for more accurate investigations as they generally occur distributed in small proportions only over a large amount of other matter besides vhich on the other hand the feebly defined and generally acid character of the colouring matters renders the preparation of definite compounds of them a matter of difficulty. Madder ranks in importance before all other colouring *principles ; the cultivatioii of the Rubia tinctoria the preparatlon of the madder and above all its manifold applications in the dyeing of cotton and in calico-printing in which it affords the most vai*ied beautiful and durable colours form important branches of agriculture and manufactures.Since Kuhlniann* first took up the chemical investigation of madder many chemists have applied their talents and powers to this subject; and it must bc gratefully acknowledged that the labours of Robiquet and Colin? Runge,j Schunck4 and Debus,fl have thrown much light on the chemical deportment of the active prin- ciples of the madder-root. A superficial contemplation of the results of these researches tvo~dcl certainly appear to point out a great want of accordance betwcen them; but on a mare strict examination the identity of the results may be discerned and the differences in the statements easily explained and adjusted.The study of the various researches on madder together with coniparative experiments made with this substance and with the splendid preparations of Messrs. Robiquet Schunck and Debus for the use of which I am indebted to Professor Liebig and Dr. Debus have shown me that madder contains-besides the yellow or orange colouring matters which do not play any important part in dyeing-two red colouring matters which have been obtained by chemists in a state of greater or less purity and have received from them various names The one of these first prepared by Robiquet and Colin and named by them AZizarine was afterwards obtained in a state of perfect purity by Runge who called it Madder-red. Persoz and * Ann. Ch. Phys.f23 XXIV 225. j-Ann. Ch. Phys. [2] XXXlV 225 j LXIII 306 $ J. Pr.Chem. V 362. 0 Ann. Ch. Pharm. LXVI 174. I/ Ann. Ch. Pharm. LXVI 351. 245 RED COLOURING MATTERS OF MADDER Gaultieis de Claubry,* obtained it in a state of less purity and described it under the name of Madi?re colorante rouge; and finally it was prepared perfectly pure by Schunck and Debus and called by the latter Lixaric acid. The second red cofouririg matter was first distinguished by Robiquet and Colin by the name of Purpurine although they did not obtain it pure ;it was first isolated by Runge and called by him Madder-purple. D ebus afterwards described it as Oxylizaric acid and lately Niggin? obtained it mixed with alizarine and described it under the latter name.Schunck has overlooked this substance; the correspondence of his analytical results vith those of Debus and some comparative experiments that I have instituted with the preparations of Schunck Debus and Robiquet show however that the alizarin of the first-named chemist is free from purpurine ;and it is very probable that in the treatment with concentrated solution of carbonate of potassa the purpurine was dissolved and only separated again in a decomposed form (possibly as alpha-or beta-resin). ALIZARINE. Alixarine is possessed of the following properties it may be obtained in two forms differing from each other in the amount of water which they contain. Hydrated alizarine occurs in small scales having the appearance of mosaic gold.The anhydrous substance has a red colour passing more or less into yellow according to the thick- ness of the crystals. This explains the difference in the statements of Debus Runge and Robiquet who describe it successively as occurring in aurora-red needles as a brownish-yellow powder and of the colour chromate of lead. It fuses when heated and sublimes in orange-coloured needles a portion being decomposed with deposition of carbon which may arise merely from the too rapid action of heat. It is moistened with difficulty by water and .vcrlien boiled with the latter dissolves with a deep yellow colour. The slightest trace of alkali (as ammonia or lime) colours the solution red; hence arises the fallacious statement of Robiquet that it dissolves in water with a rose-colour.It is considerably solnble in alcohol to which it imparts a yellow colour the solution becoming red under the same conditions as the aqueous solution. It dissolves likewise in ether with il yellom colour which is not altcred by the addition of small quantities of an * Ann. Ch.Phps. [2] XLVIXT 69. -f Phil. Mag. XXXIII 282. DR. STRECKER ON THE alkali the resulting red alkaline compound being insoluble in ether. Alizarine is easily soluble in alkalies; its solution in hydrate of potassa or of soda appears if snfficiently concentrated of a deep purple colour by transmitted light and pure blue by reflected light ; when highly diluted the solution assumes a uniform violet colour. This readily explains why Robiquet and Runge state the solution to be violet-coloured while Sc h unc k calls it purple-coloured Ali-zarine dissolves in ammonia and carbonate of ammonia with a colour similar to orchil the solution possessing no blue appearance on the surface.The cause of the difference in colour of the solutions of alizarine in caustic or carbonated alkalies evidently lies in the formation of different compounds of alizarine with the alkali. prepared one of these in the following manner Alizarine was dissolved by the aid of heat in a solution of carbonate of soda saturated in the cold ;the filtered solution deposited on cooling the compound of alizarine with soda insoluble in concentrated soda-solution. This was dried purified from an admixture of carbonate of soda by solution in absolute alcohol and precipitated from this solution in purple flakes by addition of ether.It dissolved easily in water and alcohol with the colour of orchil; the solution was coloured blue by addition of caustic soda. The compounds of alizarine with the alkalis are insoluble in cold concentrated salt solutions ; the ammoniacal solution of alizarine gives with chloride of barium a nearly pure blue flocculent precipitate; the solution from which the precipitate has been separated by filtration is colourless. Acetate of lead gives a purple-red pre-cipitate. A characteristic of alizarine is its insolubility in a cold solution of alum. When alizarine is boiled with a concentrated soln-tion of alum the liquid assumes a yellow colour like that of an aqueous solution of alizarine; on cooling the small quantity of alizarine that was dissolved separates again the liquid becoming almost colourless.Alizarine forms a red solution in hydrated sulphuric acid and is reprecipitated unchanged on the addition of water. Robiquet and Schunck have shown that alizarine is capable of producing on mordantized cloth all the colours obtained from madder. To conclude from this that alizarine is the only active dyeing principle in madder would certainly be going too far; for it will be presently shown that purpurine likewise yields durable and beautiful colours on mordantized cloths. The results of the analysis of alizarine by Schunck and Debus correspond exactly-nor does the older analysis by Robiqu et differ considerably from their numbers.Schiel’s results however RED COLOURING MATTERS OF MADDER. 247 cannot be made to correspond with them. The percentage-com-position of alizarine may perhaps be considered as established by the more recent analyses ;but in the construction of its chemical formula we meet with the difficulty of determining the equivalent of a weak acid by the preparation of neutral compounds. Schunck was led by the analysis of a lead-salt to the formula while Debu s assigns to another lead-cornpound the formula 2 PbO. C, H 0, and represents alizarine itself by the formula c30 H,o 0,. I believe I can prove that the chemical formula of alizarine is '20 H6 O6 which corresponds with sufficient accuracy with the percentage-compo- sition of this substance and its compounds and is likewise confirmed by the results of the decomposition of alizarine.The composition of alizarine dried at loo*-120° is as follows Equiv. Calc. Sch un ck. Found. Debus. (-A- (-A- C2 H 68-96 3-95 69.09 3.88 69.15 4.04 6924 4-11 6895 3-79 68.98 3-80 6878 3.78 27.26 27.22 27.20 0 27.59 27.03 26.81 26.75 100*00 100*00 100.00 lOO*OO 100.00 100*00 99.96 Schunck has also submitted hydrated alizarine to analysis; it lost on desiccation 18.3 p. c. of water which when calculated upon the above formula corresponds nearly to 4equivalents of water calculated (17.1 p. c.). The composition of hydrated alizarine is therefore C, H O6 +-4 HO. Equivalent. Calc. Found (Schunck). c20 57.14 58.97 56-94 57.02 4.76 8-19 5.13 5-87 HI0 -m OlO 38-10 --.100*00 The amount of carbon found corresponds exactly with the calcu- lated number; the discrepancy in the amounts of hydrogen found arises from the use of warm chromate of lead in the first aualysis while in the two latter the substance was even mixed in a cold mortar. DR. STRECKCR ON THE The composition of the compounds obtained by precipitating an amrnoniacal solution of alizarine with chloride of calcium and chloride of barium and when dried at 1004 corresponds to the following formula Lime-compound . . 2 0,) + 3 (CaO. HO) Calc. Found. (S chu n ck.) Percentage of lime . . 18.3 18.30 18.58 ~~ry~a-co~po~n~ . . 2 (C20H 06) -+ 3(BaO. HO) Calc.Found. Percentage of baryta . 38.0 38.03 Schunck’s lead-compound corresponds most nearly with the formula 2 (C20H 0,) +3 PbO Calc. Found (Schunck). Carbon . . . . . 36.1 37.5 36.9 Hydrogen. . . . . 1-5 1.7 1.6 - . . . . 12-1 -Oxygen . Protoxide of lead . . . 50-3 49.1 49.8 100.0 The lead-compound analysed by Deb us contains the aIizarine and protoxide of lead in another proportion which (when the sub-stance is dried at 120O) may be expressed by the formula -t-4 PbO. Calc. Found (Debus). Carbon . . b . 38.2 38.18 38.51 Hydrogen . . . . 1.6 1.97 1.98 Oxygen . . . . 12.8 -Protoxide of lead . . 47.4 47.62 -i00.0 Of the products of decompositioq of alizarine one only is accurately known that naniely which is produced by various oxidizing agents and has been described by Schunck under the name of Alizaricacid.Laurent and Gerhardt* have recently pointed out the close corre- spondence of alizaric acid in its properties and composition with Phtalic acid. By treating garancine with nitric acid these chemists obtained an acid the ammonia-salt of which yielded on sublimation a substance similar to phtaliniide in all its properties. * Compt. Rend. par Gcrhardt et Laurent 1849,222. ,)0H,(C203 RED COLOURING MATTERS OF MADDER. Hence they are of opinion that no doubt can exist with respect to the identity of alizaric and phtalic acids. I am enabled to quote some quantitative determinations which prove the identity of the acid obtained from alizarine and of phtalic acid.I am indebted to Professor Liebig for a specimen of alizaric acid prepared by Schunck himself. It accords perfectly in its physical properties with the acid obtained from naphthaline. The silver-salt of the acid dried at looo furnished on analysis the following numbers I. 0.4465 grms. of the salt burnt with chromate of lead gave 0.4195 , , carbonic acid and 0.0455 , , water 11. 0.4475 , , gave on careful ignition 0.2540 , , of silver. 111. 0,5443 , , gave. 0.3090 , , of silver. The silver-salt explodes when rapidly heated; this may be avoided by heating it gently and lighting it with a piece of burning paper. These numbers correspond in 100 parts with the composition of the phtalate of silver.Equiv. Calculated. Found. I. 11. 111,-Carbon 16 96 25.3 25.6 -.-.I Hydrogen . 4 4 1.0 1.1 -Oxygen . . 8 64 16.9 -- . 2 216 56.8 -56.7 56.8 Silver 30 380 100.0 Schun ck's analysis of his akaric acid and pyro-alizaric acid (anhydrous phtalic acid) may be quoted as further proofs of the identity of the two acids. The formula of phtalic acid is C, H6o, and that of anhydrous phtalic acid is c16 H 0,. Phtalic acid. Anhydrous phtalic acid. Calc. Mean Calc. Found. In 100 parts c16 57.8 57-5 64.9 64.0 JY 1) 3) H6 3.6 3.9 H 297 3.1 0 32-4 ->> JY IJ '€3 3806 -100.0 100.0 If we compare the formula of alizarine with that of its product of DR. STRECKER ON THE oxidation it will be found that 4 equivalents of carbon have been eliminated and that 2 equivalents of oxygen have entered into the compound.Alizarine . . . '20 O6 Phtalic acid . . . C, H 0 Difference . . C 0 The 4 equivalents of carbon are probably eliminated in the form of oxalic acid as the latter is obtained in considerable quantity in the treatment of madder with nitric acid The decomposition of alizarine by nitric acid is expressed by the following equatiou U u-ALizarine. Phtalic acid. Oxalic acid. The new formula of alizarine brings to light a close connection between this colouring matter and a substance obtained by Laureut,s in his elaborate research on the metamorphoses of naphthaline namely Chloronuphthalicacid. Tbe latter substance is Chlorinated Alizarine as will be seen by the comparison of their formuls Alizarine.. . . . C, H 0 Chloronaphthalic acid CzO {!f} 0 That the apparent relation exhibited by the fomuh of these substances really exists is proved by the close analogy of their properties and products of decomposition. The acid character of alizarine is only feeble that of chloronaphthalic acid is more strongly marked as is generally the case with chlorinated com-pounds. The ChZoronap~~~aZ~c acid of Laurent is a yellow substance almost insoluble in water dissolving in alcohol and ether in larger but still not very considerable quantity. It fuses at 200°,and may be sub- limed without change. It dissolves in concentrated sulphuric acid without undergoing decomposition. Its combinations with metallic oxides exhibit lively colours extending from yellow to bright red.Solution of potassa dissolves chloronaphthalic acid with a deep red colour. A concentrated solution deposits on cooling a crimson salt crystallized in needles whose formula according to Laurent is KO. CzoH C10,. The ammonia-salt is similar to the foregoing. * Rme Scientifique XIII. RED COLOURING MATTERS OF MADDER. 25 1 The baryta-salt is obtained by double decomposition in the form of golden-yellow needles of silky lustre which when dried at looo,have the formula BaO. C, H C10,. The lime-salt is obtained like the other salts by double decompo- sition ;it crystallizes in orange-coloured needles The strontia-salt has the same colour. Protochloride of mercury gives a red-brown precipitate ;solution of alum an orange-coloured ;solution of protoxide of lead a reddish- yellow; and solution of oxide of silver a blood-red precipitate becoming carmine red and crystalline when heated.Salts of the protoxides of cobalt and copper give carmine-coloured precipitates. Chloronaphthalic acid dyes neither mordantized cloth nor cotton mordantized or oiled for turkey red. This might have been expected the acid character of the substance being already too strongly defined. The close similarity of character between chloronaphthalic acid and alizarine-a similarity which is found only in the nearest substitution products-is further supported by the corresponding decomposition of these two substances by nitric acid.According to Laurent chloronaphthalic acid is converted by treatment with nitric acid into oxalic and phtalic acids. C,,H,C1O,+4!HO3.0,=C,,H,O,$-C,H,Os+ HC1. v Chloronaphthalic acid. Phtalic acid. Oxalic acid. The only difference consists in the simultaneous elimination of chlorine and its substitution by hydrogen. It is possible however that instead of phtalic acid a chlorinated phtalic acid was formed in which case the decomposition would correspond still more closely with that of alizarine C, H,C106 +2 HO +0 =C16H,ClO +C H 0,. Laurent has also obtained besides this chloronaphthalic acid a acid (C20{c1&} p~~uc~~~rona~ht~ali~ OJ which likewise yields carmine-coloured salts insoluble in Gater. I have myself obtained in the preparation of naphthalic acid an acid which did not yield with solution of baryta the usual golden-yellow baryta-salt but a splendid purple-red compound.I had too small a quantity of sub-stance at my command for an analysis; it was probably a bi-or terchloronaphthalic acid. I obtained simultaneously with this sub-stance a chlorinated phtalic acid which has not been described DR STRECKER ON THE hitherto I prepared the potassa-salt of this acid by saturating a boiling alcoholic solution with solution of potassa ; it quickly separated in small plates of silvery lustre which when dried at 140° gave on analysis the following numbers 0.4045 grm. of potassa-salt gave 0.2175 , , sulphate of potassa. 0.3495 , ,,potassa-salt burnt with chromate of lead gave 0.3890 , , carbonic acid and 0.0215 , ,,water These determinations correspond with the composition of bi-chlorophtalate of potassa.CaIc. Found. C, . . 30% 30.4 H . . 0.6 0.7 Cl 22% I 0 . . 20.6 -K 25.1 24.3 loooo The question now arose whether it would be possible to expel the one equivalent of chlorine from chloronaphthalic acid and to replace it by hydrogen. Two methods in particular are known for obtaining the original substance from chlorinated compounds. lSIelsens* reconverted chloracetic into acetic acid by the action of potassium-amalgam (I of potassium to 150 of mercury). The potassium dissolves without evolution of gas as long as any chlorine is contained in the organic substance in place of which hydrogen is taken up.Kolbet made use of the galvanic current for the same purpose and with great success; he passed the current into the neutral liquid by means of two amalgamated zinc plates. I have endeavoured to obtain alizaric acid from chloronaphthalic acid by both these methods without homcver arriving at the desired result. If potassium-amalgam is brought in contact with chloro- naphthalic acid and water the liberated potassa soon dissolves the acid forming a dark red liquid which however never exhibits the blue colour of the alizarine solution by reflected light. After a time the solution contained chloride of potassium and the colour of the solution diminished in intensity. A yellow precipitate was obtained * Ann. Cb. Phjs.[3] X 233. t Ann. Ch. Pharm. LIV 274. 253 RED COLOURING MATTERS OF MADDER. by the addition of an acid which proved to be unaltered chloro-naphthalic acid as it yielded with solution of baryta the beautiful golden-coloured needles already mentioned. A portion of the acid had undergone a deconiposition which was however not limited to the substitution of hydrogen for the atom of chlorine but had at once proceeded further. The insolubility of chloronaphthalic acid in slightly acidulated water precluded its decomposition in such a solution by the galvanic current. When subjected to the current in an alkaline solution chloronaphthalic acid soon underwent a change which was indicated by the decrease in the colour of the solution and the assumption of a brown coloration as also by the presence of cblorine in the liyid.But in this case likewise no alizitrine could be detected at any period of the operation. Although these experiments have led to no positive results I have no doubt that continued exertions and the application of new agentg will lead to a reaction the results of which will be more within reach of the means presented to us by the science. Chloronaphthalic acid was prepared by Laurent by treating the compound C, H C1 (chlorzcre de chloronaphtase) with nitric acid. Chlorine is passed over naphthaline until the mass at first in a state of fusion has assumed an unctuous consistence when the chloride of naphthaline is dissolved out by ether and obtained by evaporation of the ether in the form of an oily liquid.This is submitted for several days to a current of chlorine the resulting viscid matter being rendered more fluid towards the end of the operation by the applicatiori of heat. After the action is complete the substance is dissolved in boiling ether which on cooling deposits the chlorinated chloride of naphthaline; this is boiled with nitric acid till it no longer solidifies on cooling but remains in the form of a viscid mass. A yellow powder is separated by the addition of ether to which Laurent has given the name oxyde de c7zZorox~~zaphtose. Vhen treated with an alcoholic solution of potassa this substance is imme-diately converted into chloronaphthalic acid. These reactions may be expressed by the following equations c, €1 + C1 = C, H C15 + H C1.-+i-) Naphthaline. Chlorinated cliloi-ide of naphthaline. C, H?CI + 0 = C, H C120 -1-3 H C’f. + v Chloi inated chloride Oside de chloroxi-of naphthaline. IIaphtose. 254 DR STRECKER ON TEE C, H Cl 0,+ 2 KO = C, H C1 KO + K C1. Lvv-d -v-Oxide de 'chloroxi-Chloron&h thalate naphtose. of potassa. Now it is evident that if chloride of naphthaline (C2 H Cl,) were to be submitted to these reactions the final product would also contain 1 equivalent of chlorine less and 1 equivalent of hydrogen more; in fact alizarine (C2 H 0,) must then be obtained instead of C, H C1 0,. In the treatment of the chlorinated chloride of naphthaline by nitric acid a large quantity of the substance is converted into further products of decomposition namely into phtalic and oxalic acids.The chlorinated compounds withstand the oxidizing action of nitric acid much better than the normal substances and this may be the reason why chloride of naphthaline yields instead of C, H 0, only the products of decomposition of that substance namely phtalic and oxalic acids. The experiments of Schunck have shown that alizarine when boiled with nitric acid splits up readily into phtalic and oxalic (?) acids. I do not know whether I shall be able to follow up this subject; I believe however to have pointed out with sufFxient clearness in the foregoing the manner in which we may hope to obtain alizarine from naphthaline. The method would be to check the reaction at a certain point; this might be arrived at by the employment of a more feeble oxidising agent than nitric acid as the latter always effects a further decomposition.The theoretical and practical interest of the above question leads me to hope that chemists will bestow a little attention upon it. If it be considered that according to the experiments of Robiquet and Schunck alizarine not only produces the same colours as madder but even possesses advantages over the raw material; if besides this the small amount of alizarine required for dyeing and the low price of naphthaline obtained as it is in large quantities in the manufacture of coal-gas be taken into consideration it will be evident that even if a very elaborate and circuitous method should be requisite for the conversion of naphthaline into alizarine its practical application might still be found advantageous.PURPURINE. This second red colouring principle of madder differs from alizarine chiefly by its solubility in solution of alum. If a concen- trated solution of alum be boiled with purpurine the latter dissolves with il fine bright red colour; the solution has an orange colour by reflected light. Ammonia precipitated a red-lake varying in RED COLOURING MATTERS OF MADDER. colour when dry from rose to ponceau according to the qaantity of alumina present. The solubility of purpurine in solution of alum has been applied by Runge and Debus to the separation of this substance from alizarine. Purpurine differs in appearance ac- cording to the conditions under which it crystallizes.It is deposited from its solution in strong alcohol in red needles and from weak spirits in thin soft orange-coloured needles forming a matted mass when dried. These orange-coloured crystals contain water of crystallization which they part with at looo assuming a red colour. A specimen of pure purpurine containing however some red crystals (anhydrous purpurine) in admixture lost 4.9 of water at 120°. Runge describes his purpurine as occurring in orange- coloured crystallized grains and D e b us his oxylizaric acid as forming red needles from 2 to & of an inch in length. Purpurine is more easily soluble in warm water than alizarine and forms a red solution. It fuses when heated and sublimes with deposition of carbon.Its solution in alcohol has likewise a much deeper red colour than that of alizarine; it dissolves in ether and in concentrated sulphuric acid. Purpurine* may be easily distinguished from alizarine by the colour of its solution in potassa; it is bright red and does not possess the blue tint characteristic of alizarine. Purpurine gives purple- coloured precipitates with lime- and baryta-salts which are easily distinguishable from those of alizarine. The lead-compound is likewise purple. Piirpurine is also insoluble in a concentrated solution of carbonate of soda in the cold; it dissolves on ebullition but separates again perfectly from the solution on cooling. The com- pound of purpurine with potassa- (?)alkali is also insoluble in other salt -solutions.Runge has already shoton that purpurine dyes cloth purple when mordantized with alumina rose-coloured with tin-mordant ponceau-coloured with lead-mordant and violet with iron-mordant I have convinced myself that purpurine imparts to stuffs mordantizcd with alumina as well as to cotton which has been oiled and mor-dantized for turkey-red a fine deep red dye without any blue tint and that these colours are not altered by the process of raising with soap. It cannot therefore be doubted that purpurine plays a part in turkey- red dyeing as well as in the common-madder dyeing. D ebus has published several concordant analyses of purpurine (oxylizaric acid) which correspond exactly to the formula c, H 05 * I am not able to confirm the statement made by Schiel that sublimed madder- purple (purpurine) dissolves with a blue colour in solution of potassa.Purpurine repeatedly sublimed dissolved in potassa with a bright red colour. DR STRECKER ON MADDER To a lead-compound of purpurine he has assigned the formula PbO C, H 0,. It has already been seen with alizarine how little reliance can be placed on the atomic weights derived from compounds of bodies like these of feebly acid properties; the equivalent proportion C H 0 determined upon by Deb u s seems however undoubtedly correct and the most probable formula appears to be C, H 0,. Hydrated purpurine would contain according to the above determination one equivalent of water of crystallization (calc.5.3per cent). A certain connection between two substances occurring in the same plant and so similar in properties to each other might rea-sonably be expected. Debus interpreted the compositioii of alizarine and purpurine as found by him by assuming the presence of one atom more of oxygen in the former than in the latter; the endeavours to convert alizarine into purpurine by the action of oxygen were not attended with the expected result. The following experiment would however seem to indicate a reconversion of alizarine into purpurine. Some madder from Elsars was suspended in watcr mixed with fresh yeast and kept for some time in a closed vessel at atempcrature of about 30°. Fermentation was soon set up as was indicated by the brisk evolution of carbonic acid.After the lapse of two days the action terminated-the liquid was powerfully acid-and when distilled yielded alcohol and a trace of a volatile acid ;the strongly acid residue contained much phosphoric acid. The liquid was separated from the solid portion by a cloth; the solid matter removed and treated with a boiling solution of alum which assumed the exact colour of purpurine. On cooling the solution deposited besides crystallized alum a red colouring matter which dissolved again when boiled with more solution of alum and contained besides purpurine a mere trace of alizarin. The addition of sulphuric acid to the alum-solution separated a considerable quantity of purpurine which after extraction with boiling hydrochloric acid yielded from its alcoholic and ethereal solutions crystals of purpurine mixed with an amorphous substance.The alizarine appeared therefore to have disappeared while a considerable quantity of purpurine was obtained. It would however be necessary in order to prove decidedly whether alizarine is converted into purpurine by fermentation to submit pure alizarine mixed with yeast to fermentation.

ISSN:1743-6893    

DOI:10.1039/QJ8510300243

出版商:RSC    

年代:1851

数据来源: RSC

摘要:

ABSTRACTS OF PAPERS IN THE PHILOSOPHICAL TRANSACTIONS.*V BY HENRYWATTS,B.A. F.C.S. On the Diffusion of Liquids. By Professor Graham.+ Any saline or other soluble substance once liquefied and in a state of solution is evidently spread or diffused uniformly through the mass of the solvent by a spontaneous process. It has often been asked whether this process is of the nature of the diffusion of gases; but no satisfactory answer to the question appears to be obtained owing it is believed to the subject having been studied chiefly in the operations of endosmose where the action of diffusion is complicated and obscured by the imbibing power of the membrane which is peculiar for each soluble substance but no way connected with the diffusibility of the substance in water.Hence also it was not the diffusion of the salt but rather the diffusion of the solution which was generally regarded. A diffusibility like that of gases if it exists in liquids should afford means for the separation and decomposition even of unequally diffusible substances and being of a purely physical character the necessary consequence and index of density should present a scale of densities for substances in the staterof solution analogous to vapour-densities which would be new to molecular theory. 31. Gay-Lussac proceeded upon the assumed analogy of liquid to gaseous diffusion in the remarkable explanation which he suggested of the cold produced on diluting certain saline solutions namely that the molecules of the salt expand into the water like a com-pressed gas admitted into additional space.The phenomena of solubility at the same time were considered by that acute philosopher as radically different from those of chemical affinity and as the result of an attraction which is of a physical or mechanical kind. The characters indeed of these two attractions are strongly contrasted. Chemical combination is uniformly attended with the evolution of heat while solution is marked with equal 1 Phil Trans. 1850 I 1. VOL III.--NO XI 8 PROFESSOR GRAHAM constancy by the production of cold. The substances which com-bine chemically are the dissimilar while the soluble substance and its solvent are the like or analogous in composition arid properties. In the consideration of solubility attcntion is generally engrossed entirely by the quantity of salt dissolved But it is necessary to apprehend clearly another character of solution namely the degree of force with which the salt is held in solution or the intensity of the solvent attraction quite irrespective of quantity dissolved.In the two solid crystalline hydrates pyrophosphate of soda and sulphate of soda we see the same ten equivalents of water associated with both salts but obviously united with unequal degrees of force the one hydrate being persistent in dry air and the other highly eBorescent. So also in the solutions of two salts which are equally soluble in point of quantity the intensity of the attraction between the salt and the water may be very different as exemplified in the large but feeble solubility in water of such bodies as the iodide of starch or the sulphindylate of potash compared with the solubility of hydrochloric acid or of the acetate of potash which last two substances are capable of precipitating the two former by displacing them in solution.Witness also the unequal action of animal charcoal in withdrawing different salts from solution although the salts are equally soluble; and the unequal effect upon the boiling- point of water produced by dissolving in it the same weight of various salts. Besides being said to be small or great the solubility of B substance has also therefore to be described as weak or strong. The gradations of intensity observed in the solvent force are particularly referred to because the inquiry may arise how far these gradations are dependent upon unequal diffusibility ; whether indeed rapidity of diffusion is not a measure of the force in question.A number of six-ounce phials were first made use of to contain the solutions and to form what are called the Solution phials or cells. They were of the same make and selected from a large stock of the common aperture of 1.175 inch. Both the mouths and bottoms of these phials were ground flat. The mode of making an experiment and the apparatus (Fig. 1.)have already been described FIG. 1 in a paper by the author “On the Application of Liquid Diffusion to produce Decomposition.”* The characters of liquid diffusion were first ex-amined in detail in the case of chloride of sodium.(1.) Do different proportions of chloride of sodium in solution give corresponding amounts of diffused salt ? Solutions were prepared of chloride of sodium in the proportion of 100 water with 1 2 3 and 4 parts of the salt. The diffusion of all the solutions was continued * Chem. SOC. Qu. J. 111 60. ON THE DIFFUSION OF LIQUIDS. 259 for the same time eight days at the mean temperature of 52O.5 Fahr. Diffusion-product. Proportion of salt to 100 water in solution to be diffused. Xngrai ns. Ratio. 1 2-78 l* 2 5.54 1.99 3 8-37 3-01 4 11-11 400 The quantities diffused appeap therefore to be closely in pro-portion (for this salt) to the quarmtity of salt in the diffusing solution. The relation which appears in these results is dso favourabIe to the accuracy of the method of experimenting pursued.The variation from the speculative result does not in any observation exceed 1 per cent (2.) Is the quantity of salt diffused affected by temperature ? The diffusion of the same solutions of chloride of sodium was repeated at two new temperatures 39O.6 and 674 the one being above and the other below the preceding temperature. It was necessary to use artificial means to obtain the low temperature owing to the period of the season. A close box of double wdls was employed masses of ice being laid on the floor of the box and the water-jars supported on a shelf above. The water and solution were first cooled separately for twenty-four hours in the ice-box before the diffusion was commenced.It was found that the temperature could be maintained within a range of 2*or 3O for eight days. It was doubtful however whether the temperature was constantly the same to a degree or two in all the jars; and the results obtained at an artificial temperature were always less concordant and sensibly inferior in precision to observations made at the atmospheric tern-perature DIFFUSION OF CHLORIDIE OF SODIUM. Diffusion-product. Proportion of salt to 100 water. 2.63 1. 5.27 2-90 7-69 2 32 10*00 3 80 1 at 67O 3*50 I* 6.89 1.97 9-90 2.83 IJ JJ 13-60 3.89 PROFESSOR GRAHAM The proportionality in the diffusion is still well-preserved at the different temperatures. The deviations are indeed little if at all greater than might be occasioned by errors of observation.The ratio of diffmion for instance from the solutions containing 4 parts of salt is 3.80and 3.89 for the two temperatures which numbers fall little short of 4. The diffusion manifestly increases with the temperature and as far as can be determined by three observations in direct proportion to the temperature. The diffusion-product from the 4 per cent. solution increases from 10 to 13.60 grs. with a rise of temperature of 2P4 or rather more than one-third. Supposing the same pro- gression continued the diffusibility of chloride of sodium would be doubled by a rise of 84 or 85 degrees. (3). The progress of the diffusion of chloride of sodium in ex-periments of the ki12d narrated was further studied by inter- cepting the operation after it had proceeded for different periods of 2 4 6 and 8 days.The solution employed was that containing 4 parts of salt to 100 water. Two of the six-ounce phials were diffused at the sanie time for each period. Diffused in 1st two days . 3.95 grs. I 2nd 1 . . . . 3.00 , 31 3rd If 8 0 2.91 I> 4th I> . . . . . 3.26 , The diffusion appears to proceed pretty uniformly if the amount diffused in the first period of two days be excepted. Each of the phials contained at first about 108grs. of salt of which the maximum quantity diffused is 13-12 grs. in eight days or +of the whole salt. Still the diffusion must necessarily follow a diminishing progression which would be brought out by continuing the process for a longer time and appear at the earliest period in the salt of most rapid diffusion.All the experiments which follow being made like the preceding on comparatively large volumes of solution in the phial and for equally short periods of seven or eight days may be looked upon as exhibiting pretty accurately the initial diffusion of such solutions the influence of the diminishing progression being still small. The volume of water in the water-jar is also relatively so large that the experiment approaches to the condition of cliffusion into an Unlimited Atmosphere. DijTasion of various salts and other substunces.-Tn the following experiments the diffusion took place at a temperature ranging from 62O to 594 mean 60O.5 and was continued for a period of eight days; the proportion of salt in solution to be diffused being always 20 salt to 100 water or 1 to 5.The density of the solutions is added 9 ON THE DIFFUSION OF LIQUIDS. 26 1 DIFFUSION OF SOLUTIONSOF 20 SALT TO 100 WATER AT 60% POR EIGHT DAYS. Density of Anhydrous salt diffused. Name of salt. solution at 609 In grains. Means. Chloride of sodium 1.1265 58.5 Chloride of sodium. . 191265 58.87 58.68 Sulphate of magnesia . 1-185 27-42 27.42 Nitrate of soda . . . le120 52.1 Nitrate of soda . . 1.120 51-02 5 156 Sulphate of water . . 1.108 68.79 Sulphate of water . . 1 108 69.86 69.32 Crystallized cane-sugar. 1.070 26.74 26.74 Fused cane-sugar .. 1 so66 26.21 26.21 Starch-sugar (glucose) 1 *06l 26-99 26.94 Treacle of cane-sugar . 1.069 32.55 32.55 . 1.060 13.24 13-24! Gum-arabic . . Albumen. . . 1.053 3-08 3.08 The following additional ratios of diffusion were obtained from similar solutions at a somewhat lower temperature namely 48O;-chloride of sodium 100; hydrate of potash 151.93; ammonia (from a 10 per cent solution saturated with chloride of sodium to increase its density) 70 ; alcohol (saturated with chloride of sodium) 75.74; chloride of calcium 71.23; acetate of lead 45.46. Where two experiments upon the same salt are recorded in the table they are seen to correspond to within 1 part in 40 which may be considered as the limit of error in the present observations.It will be remarked that the diffusion of cane- and starch-sugar is sensibly equal and double that of gum-arabic. On the other hand the sugars have less than half the diffusibility of chloride of sodium. It is remarkable that the specifically lightest and densest solutions those of the sugars and of sulphate of magnesia approach each other closely in diffusibility. On comparing together however two sub- stances of similar constitution such as the two salts chloride of sodium and sulphate of magnesia that salt appears to be least diffusive of which the solution is densest. But the most remarkable result is the diffusion of albumen which is low out of all proportion when compared with saline bodies. The solution employed was the albumen of the egg without dilution but strained through calico and deprived of all vesicular matter.As this liquid with a density of 1.041 contained only 19-69 parts of dry matter to 100 of water the proportion diffused is increased iz= the table to that for 20 parts to correspond with the other sub- stances. In its natural alkaline state the albumen is least diffusive PROFESSOR GRAHAM but when neutralized by acetic acid a slight precipitation takes place and the liquid filters more easily. The albumen is now sensibly more dif€usive than before. Chloride of sodium appears twenty times more diffusible than albumen in the table but the disparity is really greater; for nearly one-half of the matter which diffused from the latter consisted of inorganic salts.Indeed the experiment appears to promise a delicate method of proximate analysis peculiarly adapted for animal fluids. The value of this low diffusibility in retaining the serous fluids within the blood-vessels at once suggests itself. Similar results were obtained with egg-albumen previously diluted aad well-beaten with 1 and 2 volumes of water. Nor does albumen impair the diffusion of salts dissolved together with it in the same solution although the liquid retains its viscosity. Three other substances added separately in the proportion of 5 parts to 100 of the undiluted solution of egg-albumen were found to diffuse out quite as freely from that liquid as they did from an equal volume of pure water these were chloride of sodium urea and sugar Urea proved to be a highly diffusible substance.It nearly coincided in rate with chloride of sodium. A second series of salts were diffused containing 1part of salt to 10 of water-a smaller proportion of salt which admits of the comparison of a greater variety of salts. The temperature during the period of eigbt days was remarkably uniform 600-59O. DIFFUSION OF SOLUTIONS OF 10 SALT TO 100 WATER AT 59O5. __ -_ Density of Anhydrous salt diffused. Name of salt. solution at 604 In grains. Means. -_. -.. _~_ 1 0668 32.3 Chloride of sodium . . 1.0668 32.2 32.25 Chloride of sodium. . . . . 1.0622 30.7 30.7 Nitrate of soda Chloride of potassium . . . 1.0596 40-15 40.15 1.0280 40.20 40.20 Chloride of ammonium Nitrate of potash .. . 1*0589 35.1 1.0589 36.0 35.55 Nitrate of potash . . . 1.0382 35.3 35.3 Nitrate of ammonia. . s Iodide of potassium. . 1*0673 37.0 37.0 Chloride of barium 1*0858 27.0 27.0 . 1-0576 37.18 Sulphate of water 1.0576 36.53 36435 Sulphate of water . 1.0965 15.3 sulphate of magnesia 1.0965 15.6 15.45 Sdphate of magnesia 1 *0984 15.6 Sulphate of zinc. . . . 1*0984 16.0 15.80 E(ulphateofl;inct ON THE DIFFUSION OF LIQUIDS. Before adverting to the relations in diffusibility which appear to exist between certain salts in the preceding table the results of the diffusion of the same solutions at a lower temperature may be stated. DIFFUSION OF SOLUTIONS OF 10 SALT TO 100 WATER AT 37O.5-Anhydrous salt diffused.Name of salt. In grains. Means. Chloride of sodium . . . . 22*21 Chloride of sodium . . . . 22-74! 22.47 Nitrate of soda. . . 22-53 Nitrate of soda. . . . . . 23.05 22.79 . . 31.14 31.18 Chloride of ammonium Nitrate of potash . . . . . 28-84 28.56 28.70 Nitrate of ammonia . . . 8 29.19 29.19 Iodide of potassium . . . . 28.10 28.10 Chloride of barium . . 8 21.42 21b42 Sulphate of water . . . . 31.11 Sulphate of water . . . . . 28.60 29.85 Sulphate of magnesia. . . . 13*03 Sulphate of magnesia. . . . 13-11 13*07 Sulphate of zinc . . . 11087 13.33 1260 Sulphate of zinc The near equality of the quantities diffused of certain isomorphous salts is striking at both temperatures.Chloride of potassium and chloride of ammonium give 40.15 and 40*20grs. respectively in the first table. Nitrate of potash and nitrate of ammohia 35.55 (mean) and 35.3 grs respectively in the first table and 28.70 and 29.19 Frs. in the second table. Sulphate of magnesia and sulphate of zinc 15.45 and 15% grs. (means) in the first table with 13.07 and 12.60 grs. in the second. The relation observed is the more re-markable that it is that of equal weights of the salts difised and not of atomically equivalent weights. In the salts of ammonia and potash this equality of diffusionis exhibited also notwithstanding considerable differences in density between their solutions ; the density of the solution of chloride of ammonium for instance being 1*0280,and that of chloride of potassium 1.0596.It may have some relation however but not a simple one to the density of the solutions; sulphate of magnesia of which the solution is most dense being most slowly diffusive ;and salts of soda being slower its they are generally denser in solution than the corresponding salts of potash. Nor does it depend upon equal solubility for in none of the pairs is there any approach to equality in that respect PROFESSOR GRAHAM A comparison was now made of the diffusibility of several acids diffused from 4 per cent solutions from which it appeared that hydrochloric and nitric acids were sensibly equal and had ib diffusi-bility nearly double that of sulphuric acid. The diffusion of chloride of sodium being 13.32 grs.that of hydrochloric acid was 34.1 of nitric acid 33.5 of sulphuric acid 18*48,of oxalic acid 12.38,and of tartaric acid 99'9. Difusiors of arnmoniated salts of copper.-It was interesting to compare together such related salts as sulphate of copper the ammoniated sulphate of copper or soluble compound of sulphate of copper with 2 equivs. of ammonia and the sulphate of ammonia. It is well known that metallic oxides or subsalts of metallic oxides when dissolved in ammonia and the fixed alkalis are easily taken down by animal charcoal. This does not happen with the ordinary neutral salts of the same acids which are held in solution by a strong attraction. Supposing the existence of a scale of the solvent attraction of water the preponderance of the charcoal attraction will mark a term in that scale.And if the solvent force is nothing more than the diffusive tendency it will follow that salts which can be taken down by charcoal must be less diffusible than those which cannot Of sulphate of ammonia and of sulphate.of copper solutions were prepared consisting of 4anhydrous salt to 100 water the sulphate of ammonia being of course taken as NH,O.SO,. The solution of the copper-salt was divided into two portions one of which had caustic ammonia added to it in slight excess so as to produce the azure blue solution of ammonio-sulphate of copper. The solutions were diffused for eight days at a mean tempera-ture of 64*9 for the sulphates and nitrates and 67O.7 for the chlorides DIFFUSION OR SOLUTIONS 4 SALT TO 100 WATER.Density of solution Anhydrous salt Name of salt. at temperature of diffused in grains. experiment. Mean of 2 expts. Sulpbate of ammonia . . . . . 1.05235 12-05 Sulphate of copper . . . . . 1.0369 6.35 Animonio-sulyhate of copper . 1*0308 1-44 Nitrate of ammonia . . . 1.0136 15.80 1.0323 9-77 Nitrate of copper . . . . . 1*0228 1.56 Ammonio-nitrate of copper . . 1.0100 16.19 Chloride of ammonium . . . Chloride of copper . . . . . 1.0328 10-65 Ammonio-chloride of copper . 1*0209 4-24 It will be observed that the quantky of sulphate of copper diffused out in the experiments falls from 6.35 in the neutral salt to 1.44 grs. 265 ON TEE DIFFUSION OF LIQUIDS in the ammoniated salt; of nitrate of copper from 9.77 to 1.56,and of chloride of copper from 10.65 to 4-24 These numbers are to be taken only as approximations; they are sufficient however to prove a much reduced diffusibility in the ammoniated salts of copper.Di$usion of mixed salts.-When two salts can be mixed without combining it is to be expected that they will diffuse separately and independently of each other each salt following its special rate of diffusion. (1). Anhydrous sulphate of magnesia and sulphate of water (oil of vitriol) 1 part of each were dissolved together in 10 parts of water and the solution allowed to diffuse for four days at 61O.5. The water-jar was found to have acquired Sulphate of magnesia. . . 5.60 grs.Sulphate of water . 21-92 , 27.52 grs. (2). A solution was also diffused of 1part of anhydrous sulphate of soda and 1 part of chloride of sodium. in 10 parts of water for four days at 61O.5. The salt which diffused out in that time consisted of Sulphate of soda . . 9.48 grs. Chloride of sodium . . 17-80 , 27.28grs. The sulphate of soda in the last experiment had begun to crys-tallize in the solution-phial from a slight fall of temperature before the diffusion was interrupted it circumstance which may have con-tributed to increase the inequality of the proportions diffused of the mixed salts. (3). A solution of equal weights of anhydrous carbonate of soda and chloride of sodium namely of 4 parts of the one salt and 4 parts of the other to 100 water was diffused from three four-ounce phials of 1-25inch aperture at a mean temperature of 57O.9 and for seven days.The diffusion product amounted to 17*10 17.58,and 18-13grs. of mixed salt in the three experiments. The analysis of the last product of 18.13 grs. gave Carbonate of soda. . 5.68 31.33 Chloride of sodium . 1245 68.67 18.13 10000 The least soliible of the two salts appears in all cases to have its diffusibility lessened in the mixed state. The tendency to crystal-lization of the least soluble salt must evidently be increased by the admixture. Now it is this tendency or perhaps more generally the 266 PROFESSOR GRAHAM increased attraction of the particles of salt for each other when approximated by concentration which most resists the diffusion of a salt and appears to weaken the diffusive force in mixtures as it is also found to do so in a concentrated solution of a single salt.(5). The salt which diffused from a strong solution of sulphates of zinc and magnesia consisting of 1 part of each of these salts in the anhydrous state and 6 parts of water did not consist of the two salts in exactly equal proportions. The mixture of salts bffused for eight days as in the late experiments gave the following results Exp. 1. 11. 111. Sulphateof zinc . ..8*12 r.49 8.12 Sulphate of magnesia . 8.68 8.60 8.75 16.80 16.09 1687 There is therefore always a slight but decided preponderance of sulphate of magnesia the more soluble salt in the diffusion-product.It appeara from all these experiments that the inequality of diffusion which existed is not diminished but exaggerated in mixtures a curious circumstance which has also been observed of mixed gases. Separation of salts of dg'erent buses by di$usion.-It was now evident that inequality of diffusion supplies a method for the sepa- ration to a certain extent of some salts from each other analogous in principle to the separation of unequally volatile substances by the process of distillation. The potash-salts appearing to be always more diffusive than the corresponding soda-salts it follows that if a mixed solution of two such salts be placed in the solution phial the potash-salt should escape into the water atmosphere in largest proportion and the soda-salt be relatively concentrated in the phial.This anticipation was fully verified. (1). A solution was prepared of equal parts of the anhydrous carbonates of potash and soda in 5 times the weight of the mixture of water Diffused from a small thousand-grain phial of 1.1 inch aperture into 6 ounces of water for nineteen days at a temperature above SO0 it gave a liquid of density 1.0350 containing a con-siderable quantity of the salts in the proportion of .36.37 Carbonate of soda. Carbonate of potasb .r 100*00 A partial separation of the salts of sea-water was effected in a similar manner. (2). The sea-water (from Brighton) was of density 1*0265 One thousand grs of the liquid yielded 36.50 grs of dry salts of which ON THE DIFFUSION OF LIQUIDS.2.165 grs. were magnesia. The dry salts contain therefore 6.10per cent of that earth. Six thousand-grain phials of 1.1 inch aperture were properly filled with the sea-water and placed in six tumblers each of the last containing 6 ounces of water. Temperature about 50°. The diffu- sion was interrupted after eight days. The salt8 of the sea-water were now found to be divided as follows Diffused into the tumblers . 92.9 grs. or 36.57 Remaining in the phials . . 161.1 grs. or 63.43 -cI-.--r 254.0 10000 Rather more than one-third of the salts has therefore been trans-ferred from the solution-phials to the water-jars by diffusion. Of the diffused salts in the tumblers 46.5 grs.were found to contain 1.90 gr. magnesia or 409 per cent. Hence the follow-ing result Magnesia originally in salts of sea-water 6.01 per cent. Magnesia in salts diffused from sea-water . 4-09per cent. The magnesia also must in consequence be relatively concentrated in the liquid remaining behind in the phials. A probable explanation may be drawn from the last results of the remarkable discordance in the analysis of the waters of the Dead Sea made by different chemists of eminence. The relative proportion of the salts is referred to and not their absolute quantity the last necessarily varying with the state of dilution of the saline water when taken up. The lake in question falls in level 10 or 12 feet every year by evaporation. A sheet of fresh water of that depth is thrown over the lake in the wet season which water may be supposed to flow over a fluid nearly 1.2 in density without greatly disturbing it.The salts rise from below into the superior stratum of fresh water by the diffusive process which will bring up salts of the alkalis with more rapidity than salts of the earth and chlorides of either class more rapidly than sulphates. The composition of water near the surface must therefore vary greatly as this process is more or less advanced. Chemical analysis which gives with accuracy the proportions of acids and bases in a solution furnishes no means of deciding how these acids and bases are combined or what salts exist in solution. But it is possible that light may be thrown on the constitution of mixed salts at least when they are of unequal diffusibility by meam of a diffusion experiment.With reference to sea-water for instance it has been a question in what form the magnesia exists as chloride or as sulphate ; or how much exists in the one form and how much in the other. Knowing however the different rates of diffusibility of these two salts which is nearly chloride 3 and sulphate 2 and their rela- PROFESSOR GRAHAM tion to the diffusibility of chloride of sodium we should be able to judge from the proportion in which the magnesia travels in company with chloride of sodium whether it is travelling in the large pro- portion of chloride of magnesium in the small proportion of sulphate of magnesia or in the intermediate proportion of a certain mixture of chloride and sulphate of magnesia.But here we are met by a difficulty. Do the chloride of magnesium and sulphate of magnesia necessarily pre-exist in sea-water in the proportions in which they are found to diffuse? May not the more easy diffusion of chlorides determine their formation in the diffusive act just as evaporation determines the formation of a volatile salt -producing carbonate of ammonia for instance from hydrochlorate of ammonia with carbonate of lime in the same solution ? It was proved that liquid diffusion as well as gaseous evaporation can produce chemical decompositions. Decomposition of salts 6y d@usion.-From bisulphate of potash saturated at 68O and of density 1.280 there diffused out Sulphate of potash ;:::;} Bisulphate of potash.Sulphate of water Sulphate of water 12.77 44*61 It thus appears that the bisulphate of potash undergoes decompo- sition in diffusing and that the acid diffuses away to about double the extent in equivalents of the sulphate of potash. From a 4 per cent solution of alum at 64O,the diffision-product was found to be Alum . 5.33 71.26 Sulphate of potash 2.15 28.74 7-48 100-00 This otherwise stable double salt is broken up from the high diffusibility of the sulphate of potash compared with that of the sulphate of alumina; the separate diffusibilities of these two salts were observed to be nearly as 2 to 1. It was interesting to observe what really diffuses from the arnmo-niated sulphate of copper (CuO.SO,. 2NH,+HO) and to find if the low diffusibility of that salt is attended with decomposition. The diffusion of the ammoniated sulphate of copper was therefore repeated from a 4 per cent. solution in the six-ounce solution phial for eight days at 64O.2. In evaporating the water of the jar afterwards the ammoniated sulphate of copper present was necessarily decomposed by the escape of ammonia and a subsulphate of copper precipitated. The copper found however was estimated as neutral sulphate of ON THE DIFFUSION OF LIQUIDS. copper. The diffusion-product of two experiments may be represented as follows in grains 1. 11. Sulphate of copper Sulphate of ammonia . . . 0.81 5.46- 0.97 5-53- 6.27 6.50 The abundant formation and separation of sulphate of ammonia in these experiments prove that the ammoniated sulphate of copper is largely decomposed in diffusion.From the diffusion of the double crystallized sulphate of magnesia and potash compared with that of a mixture of its con- stituent salts it appeared that they were different and that double salts dissolve in water without decomposition although the single salts may meet in solution without combining. Hence in a mixture of salts we may have more than one state of equilibrium possible. And when a salt like alum happens to be dissolved in such a way as to decompose it the constituents are not necessarily reunited by subsequent mixing. Many practices in the chemical arts which seem empirical have their foundation probably in facts of this kind.Diflusion of one salt into the solution of another salt.-It was curious and peculiarly important in reference to the relation of liquid to gaseous diffusion to find whether one salt A would diffuse into water already charged with an cqual or greater quantity of another salt B as a gas a freely diffuses into the space already occupied by another gas b; the gas b in return diffusing at the same time into the space occupied by a. Or whether on the contrary the diffusion of the salt A is resisted by B. The latter result would indicate a neutralization of the water’s attraction for a second salt which would divide entirely the phenomena of liquid from those of gaseous diffusion. A solution of 4 parts of carbonate of soda to 100 water of density 1*0406was observed to diffuse with equal rapidity into a solution of 4 parts of chloride of sodium to 100 water having the density 1.0282 as into pure water.The same solution of carbonate of soda was diffused into a solution of sulphate of soda containing 4 per cent and of density 1.0352 with a small reduction in the quantity of carbonate of soda diffused amounting to one-eighth of the whole. The sulphate of soda there- fore exercised a positive interference in checking the diffusion of the carbonate to that extent. So small and disproportionate an effect however is scarcely sufficient to establish the existence of a mutual elasticity and resistance between these two salts. Still it might be said may not the diffusion of one salt be resisted by another salt which is strictly isomorphous with the first ? The PROFESSOR GRAHAM diffusion of a 4 per cent.solution of nitrate of potash however was found not to be sensibly reduced by the presence of 4 per cent of nitrate of ammonia in the water atmosphere. These experiments were made upon dilute solutions and it is not at all improbable that the result may be greatly modified in con- centrated solutions of the same salts or when the solutions approach to saturation. But there is reason to apprehend that the phenomena of liquid diffusion are exhibited in the simplest form by dilute solu- tions and that concentration of the dissolved salt like compression of a gas is often attended with a departure from the nornial character.On approaching the degree of pressure which occasions the lique- faction of a gas an attraction appears to be brought into play which impairs the elasticity of the gas; so on approaching the point of saturation of a salt an attraction of the salt-molecules for each other tending to produce crystallization comes into action which will interfere with and diminish that elasticity or dispersive tendency of the dissolved salt which occasions its diffusion. We are perhaps justified in extending the analogy a step further between the characters of a gas near its point of liquefaction and the conditions which may be assigned to solutions. The theoretical density of a liquefiable gas niay be completely disguised under great pressure.Thus under a reduction by pressure of 20 volumes into 1 while the elasticity of air is 19.72 atmospheres that of carbonic acid is only 16.70 atmospheres and the deviation from their normal densities is in the inverse proportion. Of salts in solution the densities may be affected by similar causes so that although different salts in solution really admit of certain normal relations in density these relations may be concealed and not directly observable The analogy of liquid diffusion to gaseous diffusion and vaporiza- tion is borne out in every character of the former which has been examined. Mixed salts appear to diffuse independently of each other like mixed gases and into a water-atmosphere already charged with another salt as into pure water.Salts also are unequally diffu- sible like the gases and separations both mechanical and chemical (decompositions) are produced by liquid as well as by gaseous diffusion. But it still remains to be found whether the diffusibilities of different salts are in any fixed proportion to each other as simple numerical relations are known to prevail in the diffusion-velocities of the gases from which their densities are deducible. It was desirable to make numerous simultaneous observations on the salts compared in order to secure uniformity of conditions particularly of temperature. The means of greatly multiplying the experiments were obtained by having the solution-phial cast in a mould so that any number could be procured of the same form ON THE DIFFUSION OF LIQUIDS.and dimensions. The phials were of the form represented (Fig. 2.) FIG. 2 holding about 4 ounces or more nearly 2080 grs. of water to the base of the neck and the mouths of all were ground down so as to give the phial a uniform height of 3% inches. The mouth or neck was also ground to fit a gauge-stopper of wood which was 0.5 inch deep and slightly conical being 1.24inch in diameter on the upper and 1.20 inch on the lower surface. These are therefore the dimen- sions of the diffusion aperture of the new solution cells. A little con-trivance to be used in filling the phials with the saline solution to a constant distance of half an inch from the surface of the lip proved useful. It was a narrow slip of brass plate having a descending pin of exactly half an inch in length fixed on one side of it.This being laid across the mouth of the phial with the pin downwards in the neck the solution was poured into the phial till it reached the point of the pin. The brass plate and pin being removed the neck was then filled up with distilled water with the aid of the little float as formerly. The water-jar in which the solution-phial stood was filled up with water also as formerly so as to cover the phial entirely to the depth of 1 inch. This water-atmosphere amounted to 8750 grs. or about 20 ounces A glass plate was placed upon the mouth of the water-jar itself to prevent evaporation. Sometimes 80 or 100diffusion cells were put in action at the same time.The period of diffusion chosen was now always exactly seven days unless otherwise men- tioned. DIFFUSION OF SALTS OF POTASH AND AMMONIA Solutions were prepared of the various salts in a pure state in certain fixed proportions namely 2 4 68 and 10 parts of salt to 100 parts of water by weight. The density of these solutions was observed by the weighing-bottle at 60°. The solutions were frequently diffused at two different temperatures j one the temperature of the atmosphere which was fortunately remarkably constant during most of the experiments to be recorded at present and the other a lower temperature obtained in a close box of large dimensions containing masses of ice. The results at the artificial temperature were obviously less accurate than those of the natural temperature but have still considerable value Three experiments were generally made upon the diffusion of each solution at the higher with two experiments at the lower temperature.The diffusion-products are expressed in grains. The meaa diffusion of the different solutions containing 2,4 6# and 10 parts of certain salts was as follows Diffusion at 64O.Z 2. 4. 63. 10. Carbonate of potash . 5.45 Sulphate of potash . . 5.52 Sulphate of ammonia . 5.58 10.25 10.57 10*51 16.67 17-17' 16.79 24.69 23.62 22.20 272 PROFESSOR GRAHAM Diffusion at 370.6 2. 4. 6%. Carbonate of potash . . 3.85 7-09 11.25 Sulphate of potash . . . 3.95 7-40 11-66 Sulphate of ammonia . 3.76 7.70 10.96 The proportions diffused are sensibly equal of the different salts at the higher temperature with the exception of the largest proportion of salt 10 per cent when a certain divergence occurs.This last fact is consistent with the expectation that the diffusion of salts would prove most highly normal in dilute solutions. Some of the irregularities at the lower temperature are evidently of an accidental kind. The neutral chromate and acetate of potash were diffused at a temperature ranging from 63O to 65O or at a mean temperature of 64O.1 which almost coincides with the higher temperature of the last experiments. Diffusion at 64O.1 ; Chromate of potash 5.77 Acetate of potash . . . 5-85 2. 11-19 10.70 4. 17.60 16.48 6g. 28-75 24-85 10. The 10 per cent solution of these two salts also agrees with the same solution of carbonate of potash which was 2469 grs.Nor do the lower proportions diverge greatly from the preceding group of salts. Another pair of salts were simultaneously diffused but with an accidental difference of O0-4of temperature Mean diffusion at 64O.1 and 64O-5 2. 4. Bicarbonate of potash . . 5-81 11-01 Bichromate of potash . . 5-65 11*49 It is singular to find that salts differing so much in constitution and atomic weight as the chromate and bichromate of potash may be confounded in diffusibility. The diffusion-products of these two salts are for the 2 per cent solutions 5.77 and 5.65 grs. and for the 4 per cent solution 11-19 and 11*49grs. The bicarbonate of potash also exhibits a considerable analogy to the carbonate but resembles still more closely the acetate.It is thus obvious that similarity or equality of diffusion is not confined to the isomorphous groups of salts. The nitrates of potash and ammonia have already appeared to be equidiffusive at two different temperatures. They were diffused again in the same proportions as the last salts at a temperature varying from 63O to 67'05. Diffusion at 65O.9 2. 4. 65 10. Nitrate of potash . . . 7.47 13.97 22.37 32-49 Nitrate of ammonia . 7.73 1448 22.74 34*22 ON THE DIFFUSION OF LIQUIDS. Although these salts correspond closely it is probable that neither the diffusion of these nor the diffusion of any others is absolutely identical. The nitrate of ammonia appears to possess a sli@t superiority in diffusion over the nitrate of potash which increases with the large proportions of salt in solution.They are both considerably more diffusible than the seven preceding salts. A second pair of isomorphous salts were compared the chlorides of potassium and ammonium. Diffusion at 66O.2 2. 4. 65 10. Chloride of potassiumChloride of ammonium 7.70 .7.81 15.29 14.60 2487 24-30 36.93 36.53 The quantities diffused of these two chlorides are more closely in proportion to the strength of the original solution than with any of the preceding salts of potash. Thus the quantities diffused from the 2 and 10 per cent solutions of chloride of potassium are 7.70 and 36.93 grs. which are as 2 to 9.6 or nearly as 2 to 10 Chlo-ride of sodium was observed before to be nearly uniform in this respect; but other salts appear to lose considerably in diffusibility with the higher proportions of salt.It is possibly a consequence of the crystallizing attraction to which reference was lately made coming into action in strong solutions and resisting diffusion. The salts of potash thus appeared to fall into two groupsJthe members of which have a nearly equal diffusibility at Ieast from weak solutions such as 1or 2 per cent Of what may be called the sulphate of potash class the diffusion from 1 per cent solutions was as follows Diffusion of 1per cent solutions at 58O.5 Carbonate of potash .. 2.63 grs. Sulphate of potash ... 2.69 JJ Acetate of potash ... * 2.68 YY Chromate Gf potash ..2.83 1J Bicarbonate of potash . .2.81 1, Bichromate of potash . ..2.88 1 Diffusion of salts of the uitre clam at 64O.5 1. 2. 4. Nitrate of potash. . 3.72 7-47 13.97 Nitrate of ammonia . 3.75 7.73 14.48 Chloride of potassium 3.88 7.70 15.01 Chloride of ammonium 3.89 7.81 1441 Chlorate of potash 3-66 7*22 13-31 -7 Mean * 3.78 7.58 14.23 What is the reIation betmcen these groups ? VOL. 111.-NO. xr. T PROFESSOR GRAHAM The diffusion of 4 per cent solutions of carbonate and nitrate of potash was repeated at a temperature rising gradually from 63"to 65' during the seven days of the experiment with a mean of 64O.1. The diffusion-products of the carbonate were 10.31 10.05 and 10.44grs. in three cells; mean 10.27 grs.Of the nitrate 13.98 13.86 and 13.60 grs. mean 13.81 grs There is thus a diffusion in equal times of Carbonate of potash . 1097 1 Nitrate of potash * . . 13.81 1.3447 But the numbers so obtained cannot be fairly compared owing to the diminishing progression in which the diffusion of a salt takes place. Thus when the diffusion of nitrate of potash was interrupted every two days as in a former experiment with chloride of sodium the progress of the diffusion for eight days was found to be as follows in a 4 per cent solution with a mean temperature of 66O. Nitrate of potash Diffused in first two days . . 454 grs. Diffused in second two days . 4.13 , Diffused in third two days . . . . 4.06 , Diffused in fourth two days . 3-18 ) 15.91 The absence of uniformity in this progression is no doubt chiefly due to the want of geometrical regularity in the form of the neck and shoulder of the solution-phial.A plain cylinder as the solution cell might give a more uniform progression but would increase greatly the difficulties of manipulation. The diffusion of carbonate of potash will no doubt follow a diminishing progression also; but there is this difference that the latter salt will not advance so far in its progression owing to its smaller diffusibility in the seven days of the experiment as the more diffusible nitrate does. The diffusion of the carbonate will thus be given in excess and as it is the smaller diffusion the difference of the diffusion of the two salts will not be fully brought out.The only way in which the comparison of the two salts can be made with perfect fairness is to allow the diffusion of the slower salt to proceed for a longer time till in fact the quantity diffused is tbe same for this as for the other salt and the same point in the pro-gression has therefore been attained in both; and to note required. The problem takes the form of determining the times of equal diffusion of the two salts. This procedure is the more necessary from the inapplicability of calculation to the diffusion progression. Further allowing the Times of Equal Diffusion to be found it is ON THE DIFFUSION OF LIQUIDS. not to be expected that they will present a simple numerical relation. Recurring to the analogy of gaseous diffusion the times in which equal volumes or equal weights of two gases diffuse are as the square roots of the densities of the gases.The times for instance in which equal quantities of oxygen and hydrogen escape out of a vessel into the air in similar circumstances are as 4 to 1 the densities of these two gases being as 16 to 1 Or the times of equd diffusion of oxygen and protocarburetted hydrogen are as 1.4142 to 1 that is as the square root of 2 to the square root of 1 the densities of these gases being 16 and 8 which are as 2 to 1. The densities are the squares of the equal-diffusion times. It is not therefore the times themselves of equal diffusion of two salts but the squares of those times which are likely to exhibit a simple numerical relation.While the 4 per cent solution of nitrate of potash was diffused as usual for seven days the corresponding solution of carbonate of potash was now allowed to diffuse for 9-90days; times which are as 1 to 1.4142. The results were as follows Wused of-Carbonate of potash at 64O.3in 9 9 days 13.92 , 100*8 The three experiments OR the nitrate of potash of which 13.81 grs. is the mean were 13-98,13.86 and 13.60 grs. as already detailed. The three experiments on the carbonate were 14*00 13.97 and 13.78 grs. The difference in the means of the two salts is only 0.11 gr. The explanation of such a relation suggested by gaseous diffusion is that the molecules of the two salts as they exist in solution have dserent densities that of nitrate of potash being I and that of car-bonate of potash 2.We are thus led to ascribe densities to the solution- molecules of the salts conceived on the analogy of vapour-densities. The two salts in question are related exactly like protocarburetted hydrogen gas of density 1,to oxygen gas of density 2. The parallel would be completed by supposing that the single volume of oxygen to be diffused was previously mixed with 100 volumes of air (or any other diluting gas) while the 2 volumes of protocarburetted hydrogen were also diluted with 100 volumes of air; the diluting air here representing the water in which the salts to be diffused are dissolved in the solution-phial. The time in which a certain quantity of proto-carburetted hydrogen would come out from a vessel containing I per cent of that gas being 1 (the square root of density l) the time in which an equal quantity of oxygen would diffuse out from a similar vessel containing 1 per cent also would be 1.4142 (the square root of density 2).The diffusion was repeated of 2 per cent solutions of the nitrate and carbonate of potash at a lower temperature by about 109 TZ 276 PROFESSOR GRAHAM The mean results were Nitrate of potash in seven days 12.22 grs in two cells 100 Carbonate of potash in 9*9days 12.40 ) , 101.47 Again at a still lower temperature the times being still as 1 to 1.4142. The results were 1 per cent solution of nitrate of potash in . 6-83 grs 100 nine days at 390.7 9 J9 1 , sulphate of potash in .. . 7.04 , . 103*07 12.728days at 390.7 . With 2 per cent solutions at the same temperature Nitrate of potash 6-83 grs. 100 99-85 Sulphateof potash 6.82 , The existence of the relation in question was also severely tested in another manner. Preserving the ratio in the times of dif-fusion for the two salts the actual times were varied in duration in three series of experiments as 1 2 and 3. The experiments were made in a vault with a uniformity of temperature favourable to accuracy of observation. Eight cells of the 1 per cent solution of each salt were always diffused at the same time Nitrate of potash at 47O.2,3.50grs. 100 3.5 and 49.5 days { Sulphate of potash at 47O*3,3*50grs 100 Nitrate of potash at 48O.6 6.04grs.100 7 and 9.9 days { Sulphate of potash at 49O*1,6*20 grs 102.65 Chromate of potash at 49O*1,6.29grs. 104.14 100 10%and 14.85 days { Nitrate of potash at 48*,8*74grs grs. 100.57 Sulphate of potash at 48O*6,8*79 The concurring evidence of these three series of experiments is strongly in favour of the assumed relation of 1 to 1*4142,between the times of equal diffusion for the nitrate and sulphate of potash, and consequently of the times for the two classes of potash-salts of which the salts named appear to be types. The same experiments are also valuable as proving the similarity of the progression of diffusion in two salts of unequal diffusibility Hydrate ofpotask-Of pure fused hydrate of potash a 1per cent solution was diffused from four cells for 495 days at a mean teni-perature of 530*7,against a I per cent solution of nitrate of potash in six cells for seven days at a mean temperature Oo-1 lower or of 53O.6.The hydrate of potash which diffused vas calculated from the chloride of potassium which it gave when neutralized by hydro-chloric acid. Hydrate of potash diffused in two cells 5.97 and 6.28 grs.; mean 6.12 grs. or 3.06grs for a single cell ON THE DIFFUSION OF LIQUIDS. 277 Nitrate of potash diffused in two cells 6922 654 and 5*93 grs:; mean 6.23 grs. or 3.11 grs. for a single cell The dif- fusion of riitrate of potash being 100 that of the hydrate of potash is 98.2 numbers which are sufficiently in accordance. But the times were as 1to 1.4142; and their squares as 1to 2.SO far then as one series of expcrirnents on hydrate of potash entitles US to conclude we appear to have for the salts of potash a close approximation to the following simple series of times of equal diffusion with the squares of these times Times. Squares of times. Hydrate of potash 1 1 Nitrate of potash . 1.4142 2 Sulphate of potash . 2 4 The diffusion of hydrate of potash at 390.7 with reference to COP responding solutions of nitrate of potash for the selected times was 8s follows 100 Nitrate of potash 1 and 2 per cent solutions . . Hydrate of potash 1per cent solution . . . . . 101.3 Hydrate of potash 2 per cent solution . . 99.4 These experiments at the low temperature concur therefore with those made at the higher temperature in proving that the times of equal diffusion of the two substaiices have been properly chosen.Dafasion of salts of soda.-The only salts of soda which have yet been diffused in a sufficient variety of circumstances are the car- bonate and sulphate. These salts appear to be equidiffusive but to diverge notwithstanding more widely in solutions of the higher pro-portions of salt than the corresponding potash-salts. It is a question whether this increased divergence is not due to the less solubility of the soda-salts and the nearer approach consequently to their points of saturation in the stronger solutions The mean results at 64O were as foliows 2. 4. 62. 10. Carbonate of soda . . . 414 7.78 12.22 16.88 Sulphate of soda .4.31 817 13.50 19-14 DIFFUSION OF 1 PER CENT SOLUTIONS AT 64O9 Carbonate of soda 2.32 grs. . . . . . 100 Sulphate of soda 2938 , . . . . . 102.58 The diffusion of the carbonate of soda was further compared with the nitrate of the same base to find whether their times of equal diffusion are related like those of the corresponding potash-salts. PROFESSOR GRAHAM 1 per cent solution of nitrate of soda in 7 days at 66O.9 in four cells 11.73 grs. 100 1 per cent solution of carbonate of soda in 9.9 days at 66O.9 11-62 grs. 99.06 2 per cent solution of nitrate of soda in 7 days at 54O.3 10.10 grs. + . 100 2 per cent solution of carbonate of soda in 9.9 days, 9.95 grs. . . . . . . .. 98.51. It appears probable therefore that the times of equal diffusion of the nitrate and carbonate of soda are related like those of the nitrate and carbonate of potash that is as 1 to 1.4142. In conclusion the results of most interest may be summed up, which this inquiry respecting liquid diffusion has hitherto furnished. 1. The method may be placed first of observing liquid diffusion. This method although simple appears to admit of sufficient exact- ness It enables us to make a new class of observations which can be expressed in numbers and of which a vast variety of substances may be the object; in fact everything soluble. DifFusion is also a property of a fundamental character upon which other properties depend like the volatility of substances; while the number of sub-stances which are soluble and therefore diffusible appears to be greater than the number of volatile bodies.2. The novel scale of solution-densities possessed by the mo-lecules of salts when liquid and in solution which are suggested by the different diffusibilities of salts and to which alone guided by the analogy of gaseous diffusion we can refer these diffusibilities. Liquid diffusion thus supplies the densities of a new kind of molecules but nothing more respecting them. The fact that the relations in diffusion of different substances refer to equal weights of those substances and not to their atomic weights or equivalents is one which reaches to the very basis of molecular chemistry. The relation most frequently possessed is that of equality the relation of all others most easily observed.In liquid d_lffusion we appear to deal no longer with chemical equivalents or the Daltonian atoms but with masses even more simply related to each other in weight. Founding still upon the chemical atoms we may suppose that they can group together in such numbers as to form new and larger molecules of equal weight for different sub- stances or if not of equal weight of weights which appear to have a simple relation to each other. It is this new class of molecules which appear to play a part in solubility rand liquid diffusion and not the atoms of chemical combination. 3. The formation of classes of equidi$usive substances. These classes are evidently often more comprehensive than the isomorphous groups.ON THE DIFFUSION OF LIQUIDS. 4. The Beparation of the whole salts (apparently} of potash and of soda into two divisions the sulphate and nitrate groups which must have B chemical significancy. The same division of the salts in question has been made by &I. Gerhardt on the grourid that the nitrate class is monobasic and the sulphate class bibaaic and is further supported by the state of condensation of the vapours of acids belonging to the different groups the equivalent of hydrochloric acid giving 4 and that of sulphate of water 2 volumes of vapour a relation quite analogous to that observed in the ‘I solution-densities.” 5. The application of liquid diffusion to the separation of mixed salts in natural and in artificial operations.6. The application of liquid diffusion to produce chemical decom- posit ions . 7. The assistance mdiich a knowledge of liquid diffusion will afford in the investigation of endosmose. When the diffusibility of the salts contained in a liquid is known the compound effect presented in an endosmotic experiment may be analysed and the true share of the membrane in the result be ascertained. Researches regarding the Molecular Constitution of the Volatile Organic Bases. By Dr. A. W. Mofmann F.C.S.* Among the various classes of organic substances there is perhaps none of which from an early period chemists have so constantly endeavoured to attain a general conception as the group of com-pounds which have received the name of organic bases all-and they are now very nurnerous-being capable of combining like the met& lie oxides with acids and being derived either from vital processes in animals OF plants or from a variety of artificial reactions con- ducted in the laboratory.The remarkable analogy between all these substances and ammo- nia which in its turn imitates as it were in its chemical deportment the mineral oxides naturally attracted the notice of chemists soon after Serturner’s discovery of the first of these alkaloids in the beginning of this century. Nor have they ever since been classified separately from ammonia ; philosophers have only differed as to the mode of their relation with the typical compound. Of the theories which have been enunciated respecting the consti- tution of the organic bases there are two of chief importance which may be designated as the arnmonia- and the amidogen-theory the former having been first proposed by Ber elius,? while the latter * Phil.Trans. 1850 I 93. .t. Trait6 de Chimie TI 2. 280 DR. HOFMANN we owe to Liebig.* Accordin5 to the former of the two chemists the ammonia would pre-exist in the organic bases; these bodies TI ould be conjugated compounds of ammonia with various adjuncts containing either carbon and hydrogen or these elements together with nitrogen oxygen and even sulphur compounds in which the original character of the ammonia has only been slightly modified by the accession of the adjunct. This view is chiefly supported by the mode and the proportions in which these alkaloids combine with acids and by the fact that various organic substances by directly uniting with ammonia give rise to the formation of basic compounds which are perfectly analogous to the alkaloids occurring in the eco- nomy of nature.According to Liebig’s opinion ammonia would no longer exist in the organic bases. At the time when Liebig$ wrote upon this subject the attention of chemists was much engaged with the study of the amides the prototype of which oxamide had then been discovered by Dumas. These substances all strictly neutral originate from ammonia by the loss of 1 equivalent of hydrogen which is abstracted by the oxygen or chlorine of certain electro-negative bodies (as in the formation of oxamide and benza-mide) a hypothetical substance amidogen H N remaining in combination with the oxide or chloride deprived of 1 equiv.of oxygen or chlorine. Liebig thought that the formation of the organic bases might take place in a similar manner namely by a reduction of ammonia to the state of amidogen by the action of electro-positivc organic oxides. Each of these theories being expressed in il simple formula the organic bases according to Berzelius would be represented by the terms H N 4-x while Lie big’ s view would characterize them as H N 4-y X denoting generally an organic compound containing carbon hydrogcn and possibly nitrogen oxygen and sulphur ; while Y ex-presses an organic oxide chloride &c. minus 1 equiv. of oxygen chlorine &c.Objections have been raised aFainst eitner theory and the opi- nions of cheniists have remained divided. Liebig has not returned any more to the subject but Berzelius took frequent occasion both in his “Annual Report,” and in the several editions of his (‘Trait6,” to defend his notion by the skilful interpretation of‘ every new fact which was elaborated by the progress of the science. The weight of * Handworterbueh der Chemie von L i e b i g W b h 1e r und P o g g e n d o r f f Bd. I 699. Artikel Organische Basen. .t. LOC,cit 235. ON THE VOLATILE ORGANIC BASES. 28 I his authority has n& been without influence for it cannot be denied that Berzelius's qiew has become more and more generally accepted especially since a series of comparative researches conducted of late upon the derivatives of the salts of ammonia and of organic bases appeared to give fresh support to this theory.These experiments pointed out that the elimination of hydrogen from organic bases and ammonia is by no means confined to 1 equivalent; oxalate of ammonia which by the loss of 2 equivs. of water is converted into oxamide when deprived of the whole of its hydrogen in the form of water becomes cyanogen (oxalonitrile) ; an analogous change occurs with the acid salts of ammonia resulting in the formation of two classes of compounds differing the one by 2 the other by 4 equivalents of water from the original salt. The representation of several of these groups in analogous deriva- tives from the salts of organic bases especially from the salts of aniline could not but strengthen the belief that ammonia actually pre-exists in the organic alkaloids.Incidentally to some researches communicated to the Chemical Society of London,* I gave a synop-sis of all the facts supporting the view of Berzelius. The prosecution however of this inquiry has elicited many points which are scarcely reconcilable with this theory. In another paper? I endeavoured to show that the force of the argument in favour of this view derived from the considerations just stated is greatly neu- tralized on the completion of the comparison between the two series by the failure of the analogy just at the point where its occurrence would have been most decisive. Now this very failure is not only in perfect harmony with but would be required by the theory of amidog en -b a ses .Yet stronger grounds for the acceptation of the latter view have been afforded by a splendid investigation of M. Wurtzt on the compounds of ethers with cyanic acid which have actually realized a series of substances anticipated in a most remarkable manner by Liebig on the theoretical ground of his conception of the nature of these compounds. Instances of such anticipation of discovery are so rare that I may be allowed to quote the words in which Liebig predicted nearly ten years ago the discovery of M Wurtz :-" If," said Liebig,$ in continuing the development of his ideas respecting the constitution of the organic bases '(we were enabled to replace by amidogen the oxygen in the oxides of methyl and ethyl in the oxides of two basic radicals we should without the slightest doubt * Researches on the Volatile Organic Bases 111.Action of Chloride Bromide and Iodide of Cyanogen upon Aniline; Chem. SOC.Qu J. I 285. ./-Chem. Soc. Qu. J. 11 331. 1 Compt. Rend. XXVIII 223 LOC.cit. 235. DR. HOFMANN obtain a series of compounds exhibiting a deportment similar in every respect to that of ammonia. Expressed in symbols a compound of the formula C H,. H N = E. Ad would be endowed with basic properties.’’ Now these compounds imagined in 1840 by Liebig in illustra- tion of his views have sprung into existence in 1849 with all the properties assigned to them by that chemist.At the beginning of the present year M. Wurtz in investigating the cyanates of ethyl methyl and amyl arrived at the unexpected result that these com- pounds when decomposed by potassa undergo a change analogous to that of cyanic acid. This acid when treated with potassa yield- ing carbonic acid and ammonia the corresponding ethers were split into carbonic acid and compound amnionias of the exact formula indicated in Liebig’s suggestion. It would be difficult to imagine a more brilliant triumph for any theoretical speculation ;I have however no doubt that even the illus- trious propounder of this view is at present far from believing that all the organic bases are amidogen-compounds. The progress of our knowledge has changed the form of this view without shaking its foundation.A good theory is more than a temporary expression of the state of science collecting under a general view the facts acquired up to the moment of its birth. It will not like ephemeral hypo- thesis vanish before the light of succeeding discoveries but expand- ing with the growth of science it will still correctly represent the known facts though of necessity modified into a more general expression. Such a theory then was that of Liebig. Resting as it did upon the facts observed in the formation of the neutral amides it was as originally framed an expression of the knowledge we then possessed. Subsequent researches showed that it was not only the 1 equivalent of hydrogen (the abstraction and replacement of which had led us to amidogen and the amides) that could be removed from the ammonia but that similarly 2 equivalents and even the whole of the hydrogen could be withdrawn from their position in this base and substituted by other atoms as in the imides and nitriles.If then we give to Liebig’s view the extension of which it natu-rally admits and which is demanded by the onward steps of science we arrive at a more general conception of the nature of the organic bases; amidogen and the amides now presenting themselves to us only as particular instances of the permutations possible among the elements of the primary type ammonia. It seemed but logical to look among the bases for analogues too of the imidogen-compounds and the nitriles. In other words it appeared desirable to inquire ON THE VOLATILE ORGANIC BASES.283 whether the several equivalents of hydrogen in ammonia could not be replaced not only by atoms neutralizing the basic properties of the original system but also by elements or groups of elements not affecting or but slightly modifying the alkaline character of the primary compound. Were this possible we should arrive at the formation of three classes of organic bases derived from ammonia by the replacement respectively of 1 2 or 3 equivalents of hy-drogen. Expressed in formdze these compounds would be first class provisionally called amidogen-bases. X second class provisionally called imidogen-bases. Y XI N =Bases of the third class provisionally called nitrile-bases. The bases belonging to the first class are pretty numerously repre- sented.Aniline methylamine ethylamine amylamine when con-sidered as amidogen-compounds belong to this group. } N = Methylamine N = Aniline ::> c, H c H3 H" } N = Ethylamine N = Amylamine H c,,H 1 c49 Bases of the second and third of the above classes had not been hitherto obtained although it is not improbable that many of the alkaloids whose constitution is at present perfectly unknown may be found on a closer investigation to be members of these latter groups. ACTION OF PHENYL-ALCOHOL ON ANILINE My endeavours to introduce into aniline a second equivalent of phenyl in order to convert Hl H1 DR. HOFMANN have been unsuccessful up to the present moment.I had hoped that this conversion might be effected by the action of phenyl-alcohol on aniline according to the followiiig equation H Phenyl-alcohol however has neither at the common nor at a high temperature-the mixture was exposed for several days in a sealed tube to 250° in an oil-bath-any action upon aniline. This experiment when repeated for a longer period might possi- bly give a more satisfactory result. It is known that ammonia by a similar treatment with phenyl-alcohol is likewise only very slowly converted into aniline. The action of chloride and bromide of phenyl C, H C1 and C, H Br upon aniline promised a better result; but the difficulties which I encountered in preparing these compounds which are as yet but very imperfectly investigated deterred me from further pursuing this direction of the inquiry.Much more successful were my endeavours to substitute methyl ethyl and amyl for the remainder of the basic hydrogen in aniline ACTION OF BROMIDE OF ETHYL UPON ANILINE. On adding dry bromide of ethyl to aniline no change takes place in the cold but on gently heatin8 the mixture in an apparatus which will allow the volatilized bromide to return to the aniline a lively reaction ensues. The liquid remains for some time in a state of ebullition and solidifies on cooling into a mass of crystals. If a cold mixture of the two bodies be left for a few hours it deposits crystals which are much more definite than those obtained on the cooling of the hot solution. In either case the fluid assumes a deep amber colour which approaches brown and the crystals are usually slightly yellow.These crystals vary in composition according to the proportions in which the two bodies have becn mixed. If a very large excess of aniline has been used they are of a prismatic cha-racter and consist of pure hydrobromate of aniline. On the other hand if the bromide of ethyl predominates to a con- siderable extent the crystals are flat four-sided tables sometimes of considerable size. Several analyses the details of which will be found below showed that they were the hyclrobroniate of a new base,* represented by the formula * Frequently as may be imagined mixtures of the two hydrobromates are deposited according to the proportion in which the constituents are mixed.ON THE VOLATILE ORGANIC BASES. i. e. of aniline in which 1 equiv. of hydrogen is replaced by 1equiv. of ethyl or ammonia in which 2 equivs. of hydrogen are replaced, the one by phenyl the other by ethyl The same base is contained in the free state either alone or mixed with aniline in the mother- liquor of the crystals of hydrobromate of aniline ; while the mother- liquor of the hydrobromate of the new base especially if a large excess of the bromide has been employed and after some days’ standing consists of nearly perfectly pure bromide of ethyl only a small quantity of the hydrobromate in question being kept in solu-tion. The formation of the new basic compound for which I propose the name Ethylaniline or Ethylophenylamine takes place by the removal from aniline of 1 equiv.of hydrogen in the form of hydrobromic acid for which an equivalent of ethyl is substituted the compound thus produced uniting with the hydrobromic acid. Hence the action of bromide of ethyl upon aniline may be repre- sented by the following two simple equations 2C, H N + C H Br = C,,H7 N. H Br + C, H, N +u-u Aniline. Bromide of Hydrobromate of E thylaniline ethyl. aniline. Anhe. Bromide of Hj-drobrbmate of ethyl. ethylaniline. Ethylaniline(~~~~Zo~~en~Za~ine) .-This base may be readily ob-tained in a state of purity by decomposing the solution of the hydro- bromate with a concentrated solution of potassa. A brown basic oil yises at once to the top of the liquid; it is separated by means of a pipette or a tap-funnel and subjected to rectification after having been freed from water by standing over solid potassa.Thus a colourless transparent oil is obtained which rapidly turns brown on cxposure to air and light and has a very high refractive power. It has all the properties of the oily bases in general. From anilinc it is distinguished by a slight difference in the odour perhaps imper- ceptible to an inexperienced nose by a higher boiling-point and a lower specific gravity. Ethylaniline boils (from platinum) constantly at 204*,the boiling-point of aniline being 182O; the specific gravity of this base is 0954 at ISo that of aniline being 1.020 at 16O. Ethylaniline does not exhibit the violet coloration with chloride of lime which characterizes aniline.Its acid solutions impart a yellow colour to fir-wood and the pith of elder-tree although less intensely than those of aniline. By dry chromic acid the base is inflamed like aniline. Analysis led to the formula DR HOFMANN The aalts of ethylaniline are remarkable for their solubility espe- cially in water. They are not easily obtained in well-defined crys- tals from an aqueous solution. From alcohol in which they are somewhat less soluble than in water several salts may be readily crystallized. Both the hydrochlorate and oxalate are obtained only on evaporating their solutions nearly to dryness when the salts separate in the form of radiated masses; the sulphate and nitrate have not as yet been obtained in the solid form.Hydrobromute of Ethyluniline.-The hydrobromate is extremely soluble in water but crystallizes on spontaneous evaporation of its alcoholic solution in splendid regularly formed tables of consider-able size and perfect beauty. I intend to give the measurement of these crystals in a future communication. The composition of this salt dried at looo is represented by the formula CI6 H, N H Br. The hydrobromate of ethylaniline when gently heated sublimes like the corresponding aniline-salt in splendid needles but when subjected to the action of a rapidly increasing heat it undergoes a very remarkable decomposition being redecomposed into aniline and bromide of ethyl. On addition of hydrochloric acid to the distillate the aniline dissolves while the bromide of ethyl collects as a heavy oil at the bottom of the vessel.C16HI N. H Br = C, H7 N + C H Br -uu Hydrobromate of Aniline. Bromide of ethylaniline. ethyl. I have in vain tried to split hydrobromate of aniline according to the equation C, H N. H Br = H N + C, H Br -+ Hydrobromate of Bromide of aniline. phenyl. This salt sublimes even when suddenly heated without any decomposition. Platinum-salt of -Ethylanilk-I have controlled the formula of ethylaniline moreover by the analysis of the platinum double salt of this substance. This salt is likewise very soluble and may by this property be distinguished from the corresponding aniline-salt ; on addition of a concentrated solution of bichloride of platinum to a concentrated solution of this hydrochlorate a deep orange-red oil is deposited which solidifies sometimes only after half a day with crystalline texture.If a moderately concentrated solution be em-ployed the salt crystallizes in the course of a few hours in magni- ficent yellow needles often an inch in length. On account of its great solubility in water and alcohol it has to be washed with a 287 ON THE VOLATILE ORGANZC BASES. mixture of alcohol and ether in which the latter predominates. It may be dried at looowithout decomposition. Formula C, H, N. H Cl Pt CI,. Terchloride of gold and protochloride of mercury yield with solu- tions of ethylaniline yellow oily precipitates which are very readily decomposed. Of the products of decomposition of ethylaniline I know as yet almost nothing although they will not be deficient in interest in a theoretical point of view.The action of bromine gives rise to the formation of two corn- pounds both crystalline one basic the other indifferent and cor-responding probably to tribromaniline. Neither of these substances has yet been analysed. On passing cyanogen into an alcoholic solution of ethylaniline short yellow prisms are deposited after some time which are evi-dently cyanethylaniline Cy C, HI N corresponding to cyaniline and cyanocumidine.* This new cyanogen-base dissolves in dilute sulphuric acid and is thrown down from this solution by ammonia in form of a floury precipitate. The hydrochlorate like the corre-sponding ycaniline-salt is very insoluble in hydrochloric acid.It may be obtained in fine crystals on addition of hydrochloric acid to a solution of the base in dilute sulphuric acid. Cyanethylaniline, like cyaniline forms a very soluble platinum-salt. I have made also some qualitative experiments respecting the deportment of ethylaniline with chloride of cyanogen. This gas is rapidly absorbed much heat being evolved. On cooling the mass solidifies into a resinous mixture of a hydrochlorate and a neutral oil which separates on addition of water. The base separated from the hydrochlorate is an oil and volatile ;while melaniline produced in the corresponding reaction of chloride of cyanogen with aniline is solid and non-volatile. Bisulphide of carbon gives rise to a gradual evolution of hydro-sulphuric acid no crystals being deposited from the uiixture.Phosgene gas acts powerfully on ethylaniline a liquid compound being formed together with hydrochlorate of ethylaniline. No analysis having as yet been performed of these compounds I refrain from entering into any further details. ACTION OF BROMIDE OF ETHYL UPON ETHYLANILINE. The phenomena attending the action of bromide of ethyl upon ethylaniline resemble those which are observed in the corresponding treatment of aniline. The reaction however is less powerful another * Chem. SOC. Qu. J 1 159. DR HOFMANN equivalent of hydrogen in aniline being less easily eliminated or replaced. Four or five days elapse before the separation of crystals commences at common temperatures.The formation however is considerably accelerated on application of heat. The experience obtained in the preparation of ethylaniline sug-gested at once the use of a very large excess of bromide of ethyl by which the formation of one compound only was secured. The mixture assumed a light-yellow colour turned gradually brown and deposited after five days four-sided tables of considerable size and remarkable beauty. The mother-liquor was coloured bromide of ethyl leaving when distilled off a small quantity of the same crys- talline compound. The substance in question was the pure hydrobroniate of a new base which is represented by the formula i. e. of ethylaniline in which 1 equiv. of hydrogen is replaced by ethyl or aniline in which 2 equivs.of the same radical are substi- tuted for a corresponding number of hydrogen-equivalents or lastly ammonia in which the 3 equivalents of hydrogen are replaced the one by phenyl the two others each by ethyl. The formation of this new substance €or which I propose the name diethylaniline or diethylophenylamine requires no further illus- tration it is absolutely analogous to the production of ethyl-aniline Diethy luniline (Diethyl0;vhenylamine).-The preparation of this compound in a state of purity resembles that of the preceding base whose physical properties have been only slightly modified by the introduction of the second equivalent of ethyl. The specific gravity wasfound to be 0.939 at 18* showing a slight decrease when com- pared with that of ethylaniline (0.954).The boiling-point however was raised nearly 10 degrees ;diethylaniline boils quite constantly at 213O.5. Diethylaniline is moreover distinguished from ethylani- line by remaining perfectly bright and colourless when exposed to the air. Like ethylaniline it still imparts a yellow colour to fir-wood; but like the former fails to affect a solution of hypochlorite of lime Composition C," I& N. Hydrohornate of DiekhyluniZine.-I have mentioned this salt when speaking of the formation of the second base. It is extremely solu-ble and resembles in every respect the corresponding ethylaniline- compound. Composition C, H, N N Br ON THE VOLATfLE ORGANIC BASES. The hydrobromate of diethylaniline when gently heated fuses and sublimes like the corresponding aniline- and ethylaniline-salts.When rapidly heated it is entirely converted into a colourless oil which distils over. This oil contains equal equivalents of bromide of ethyl and ethylaniline. By this distillation we obtain indeed the very constituents from which the hydrobroniate was originally pre- pared and which would of course reconvert themselves into hydro- bromate of diethylaniline. Only a trifling amount of undecomposed liydrobromate covers after the distillation is finished the sides of the retort in the form of a radiated coating. The peculiar deportment then of the hydrobromates of the ethyl- bases and probably of all their salts allows us to remove the several equivalents of ethyl one after the other from our fabric in the same manner as we had inserted them.When first I became acquainted with diethylated aniline having then already observed the deportment of the salts of ethylaniline which under the influence of heat are reconverted into aniline I indulged for a moment in the pardonable illusion that the salt of diethylaniline would exhibit the meta-morphosis C, H, N. H Br = C, H N + C H Br L7F-L v u Hydrobrbmate of Aniiine. Bromide of diethylaniline. butyl. a mode of reaction which would have afforded a passage from the ethyl- into the butyl-series. This step however is reserved for a more fortunate experimenter. Piatinurn-salt of Diethylaniline.-This salt resembles the corre-sponding compound of ethylaniline.On addition of a concentrated solution of bichloride of platinum to the hydrochlorate it is precipi-tated in the form of a deep orange-coloured oil which rapidly solidifies into a hard crystalline mass. If the solutions are mixed in a dilute state the salt is separated after some time in cross-like yellow crystals. It is not nearly so soluble in water and alcohol as the eth ylaniline-salt . Formula C, H, N .H C1. Pt C1,. I have not examined any other of the salts of diethylaniline :their deportment resembles in every respect that of the ethylaniline-salts. ACTION OF BROMIDE OF ETHYL ON DIETEYLANILINE. If we assume that the series of bases aniline ethylaniline and diethylaniline arise from the gradual elimination of the 3 equi-valents of hydrogen in ammonia and their substitution by 1equiva-lent of phenpl and 2 equivalents of ethyl it is difficult to imagine that bromide of ethyl should have any further action on cliethylani-VOL IIT.-NO.XI. u 290 DR. HOFMANN line this compound ammonia containing according to this view no longer any replaceable hydrogen. This conclusion appears to be supported by a series of experiments performed for this purpose; still the results obtained have elicited some points which require further elucidation. In aniline ethylaniline and diethylaniline then we have three bases which may be considered as derived from ammonia by the elimination and replacement of its three hydrogen-equivalents. The successive formations of ethylaniline and diethylaniline from aniline have been detailed in the preceding paragraphs; the passage of ammonia into aniline when exposed to the action of a phenyl-compound has been proved at an earlier period by some experiments made jointly by M.Laurent and myself upon the action at a high temperature of hydrated oxide of phenyl on ammonia. In this reaction a small but unequivocal quantity of aniline is formed. The formation of aniline ethylaniline and diethylaniline appeared to have established in a sufficiently satisfactory manner the point of theory which is here in question; still I thought desirable the acqui- sition of additional facts in support of the position to which this inquiry has conducted me. Thus I have been led to study the action of bromide of ethyl upon several of the derivatives of aniline and to try whether other alcohol-radicals such as methyl and amyl woulcl have a similar action; lastly in order to complete the investigation I was obliged to leave the amidogen-bases altogether in order to submit the typical ammonia itself to examination.Among the bases derived from aniline there is a class whose deportment with bromide of ethyl appeared to be more particularly worthy of a careful investigation. This is the group of compounds produced from aniline by substitution and embracing chloraniline dichloraniline and trichloraniline the corresponding bromanilines iodaniline and nitraniline. The question arose in what manner will these substances in which the original aniline has lost already a certain quantity of its hydrogen comport themselves under the influence of bromide of ethyl? The answer afforded by experiment was unequivocal and in perfect accordance with the result antici- pated bytheory although it may here at once be stated that the difficulty of obtaining the compounds in question in suflicient quan- tity has prevented me from pursuing this part of the investigation as far as I could have wished.ACTION OF BROMIDE OF ETHYL UPON CHLORANILINE. A solution of chloraniline in dry bromide of ethyl exhibits no apparent change even after several days’ exposure to the temperature of boiling water. On adding however water and distilling off the excess of bromide of ethyl it was found that the chloraniline had been converted into a hydrobromate which was held in solution ON THE VOLATILE ORGANIC BASES.291 scarcely a trace of uncombined base being left. Addition of potassa to the solution of the hydrobromate separated at once a yellow oily base of a very characteristic aniseed-odour differing from chlorani- ine in many respects. It remained liquid even at the temperature of a cold winter day while chloraniline is distinguished by the facility with which it crystallizes. Its salts are much more solublc than the corresponding chloraniline-salts I have only seen the sul- @ate and oxalate in a crystallized state. This liquid base is evidently ethylochloraniline I am sorry that I have not been able to verify this formula by direct analysis. The amount of substance at my disposal precluded the idea of submitting it to the processes of purification necessary before combustion.1 had hoped to fix its composition by the determina- tion of the platinum in the platinum-salt. Unfortunately this salt separated in the form of a yellow oil which could not by any means be made to crystallize. Obliged to desist from direct analysis 1 endeavoured to gairi the requisite data by another mode of pro-ceeding. ACTION OF BROMIDE OF ETHYL UPON ETHYLOCHLORANILINE. Recollecting that in almost all the instances which I have ex- amined the tendency exhibited by the various bases of producing readily crystallizable platinum-salts increased with the degrce of their ethylation I subjected the whole aniount of the still hypothe- tical ethylochloraniline after having dried it by a current of hot air to the action of a considerable excess of bromide of ethyl.After two days’ exposure to 1000 the mixture was found to contain a hydro-bromate in solution not a trace of free base being left. There was no doubt that a second equivalent of ethyl had been assimilated. On decomposing the hydrobrom ate with potassa an oil separated resembling in its appearance and also in its odour the preceding compound. An attempt to purify the ethylochloraniline from the yotassa by distillation with water having failed on account of the high boiling-point of this substance the purification of the diethylo- chloraniline for as such the new compound was to be considercd was at once effected with ether. The ethereal solution of the oil was carefully washed with water to remove adhering potassa and eva-porated the yellow oil rcmaining after this treatment was dissolved in hydrochloric acid and the solution mixed with biehloriile of platinum.Immediately a splendid orange-yellow crystalline precipi- tate was separated which after washing with water was fit fbr analysis. This salt fused at looo. Formula C, H, C1 N. H C1. Pt Cl,. u2 DR HOFMANN This result shows that chloraniline when subjected to the action of bromide of ethyl exhibits absolutely the same deportment as aniline itself two equivalents of ethyl being consecutively intro- duced which give rise to the formation of two new terms which demand the names ethylochloraniline (ethylochlorophenylamine) and diethy lochloraniline (diethylochlorophen ylamine) .ACTION OF BROMIDE OF ETHYL UPON BROMANILINE. The absolute analogy existing between chloraniline and bromani- line to which I have alluded in a former paper,* is maintained also in the deportment of these two substances towards bromide of ethyl. Bromaniline is rapidly converted into hydrobromate of ethylobro- maniline which could not except by analysis be distinguished from the corresponding chlorine-base. The platinum-salt being likewise a viscid oil I have omitted to analyse it. There is however no doubt about the existence of an ethylobronianiline C, H, Br N. I have not attempted to ethylate this compound any further. ACTION OF BROMIDE OF ETHYL UPON NITRANILINE. Ethylonitraniline (Ethyloiiitrophenylamine).-Nit raniline readily dissolves in bromide of ethyl.The solution soon deposits even at the common temperature pale- yellow crystals of considerable size. At the boiling temperature of water the conversion is rapidly accom- plished. On addition of an alkali to the hydrobromate the ethylo- nitraniline separates as a brown oily mass which solidifies after some time with crystalline structure. In this substance as well as in the other ethylated bases the properties of the mother-compound are only slightly modified. Thus we find in the base ethylonitraniline still the yellow colour of nitraniline which it readily imparts to the skin but which it loses altogether in its salts. These salts are as easily soluble in water as the corresponding nitraniline-compounds if not even more so and possess the same peculiar sweetish taste; they all crystallize however on evaporating their solutions nearly to dryness.Ethylonitraniline dissolves readily in ether and alcohol less so in boiling water; from a solution in the latter the base is deposited in stellated groups of yellow crystals which are readily distinguished from the felted mass of long needles separated on cooling from an aqueous solution of nitraniline. I have fixed the composition of ethylonitraniline by a singIe number namely by the determination of the metal in the platinum double salt. This compound is prepared by adding bichloride of platinum to a very concentrated solution of the hydrochlorate; this * Chem.SOC. Mem. 11 291. ON THE VOLATILE ORGANIC BASES. must not contain much free acid in which the salt would redissolve. After a short time pale-yellow scales are separated which have to be washed with cold water. Composition C16 HI N 0,. H c1. Pt Cl,. The nitraniline-salt contains 28.66 per cent of platinum. I have not prepared a diethylonitraniline. The deportment of chloraniline bromaniline and nitraniline with bromide of ethyl appears to throw much light upon the con-stitution of these substitution-bases. The possibility of introducing into these substances 2 equivalents of ethyl shows that they must contain the same amount of basic hydrogen (an expression by which I may be allowed to represent briefly the hydrogen of the ammonia-skeleton) as aniline itself and hence it is evident that it was the hydrogen of the phenyl which was replaced by chlorine bromine and hyponitric acid in the transformation of aniline into its chlorinated bromiuated &c.relatives. This transformation is due to a secondary substitution affecting the hydrogen in the radical which replaced the original ammonia- hydrogen; and the constitution of the substances in question may hence be graphically represented by the following formu12 H Chloraniline . . . *{ c,t H Ethylochloraniline . + . Diethylochloraniline . .{:;2 (!i)}N* H Bromaniline . . . Ethylobromaniline . . . Nitraniline . . . . . DR. HOFMANN This mode of viewing their constitution is in perfect harmony with the facts at present in our possession both as regards the deport- ment of the substitution-anilines and the substances similarly derived from hydrated oxide of phenyl.Experiment has shown that in aniline 1 2 or 3 equivalents of hydrogen may be replaced by chlorine bromine and probably also by the elements of hyponitric acid.* In these substances their basic properties gradually diminish with the successive insertions of chlorine or bromine into the compound Bromaniline still retains a strongly alkaloidal character which in dibromanilinc is so far impaired that by simple ebullition it is separated from its aqueous saline solutions ; tribromaniline lastly is a perfectly indifferent compound. Now if we recollect that in monobroniinatecl and dibrominated phenole (obtained by ill.c1ahours by distilling respectively bromosalicylic and dibro-uiosalicylic acid) the original character of hydrated oxide of phenyl is gradually altered and becomes in tribromopbenole (bromo-phenisic acid of ill Laurent) powerfully acid we cannot be sur-prised to find that the gradual development of electronegative properties in the radical should affect the nature of a basic system in which it replaces hydrogen. We have two parallel groups of bodies the chemical character of which is differently affected by the modi- fication induced in the radical existing in both by the assimilation of bromine. Hydrated protoxide of phenyl HO. C, H 0 slightly acid. Bromophenole . . . . . HO C, { z }O,more so Dibromophenole.. . . €30.C, { 2 }O more so. i:3} Tribromophenole } * Bromophenisic acid { '153 o,Po~erfullYacid* * At the present moment we have only nitraniline but it is scarcely to be doubted that we shall soon become acquainted with the nitro-terms corresponding to dichlo- raniline and trichloraniline. Recent researches of M. Cahows (Ann. Ch. Phys. [3] XXXVII 439) on the derivatives of anisole have pointed out the first alkaloid contain- ing 2 equivs. of hyponitric acid. Anisidine . . . C, II N 0,. Nitranisidine . . C14{ }N 0,. Dinitranisidine . C14{ H7 PO,) }N 0,. In this series oaly trinitranisidine C 1N 0,is wanting. {(a4l3 ON THE VOLATILE ORGANIC BASES. . . . . . {c12EH5} Phenylamine N powerfully basic.Tribromophenylarnine (tribromaniline) is a compound differing in its nature in no way from oxamide. Both these substances are ammonia whose basic character has been counterbalanced by the insertion of a powerfully electronegative radical in the place of' one of the hydrogen-equivalents. These two substances when subjected to the influence of strong acids comport themselves in exactly the same manner; they both reproduce ammonia the one with formation of tribromophenisic the other of oxalic acid. The paragraphs now following are devoted to a brief account of the bases derived from aniline by the insertion of methyl and amyl. I have not however followed out the examination of these sub-stances to the same extent the principle having been in fact sufficiently established by the formation of the ethyl-bodies.ACTION OF BROMIDE AND IODIDE OF METHYL UPON ANILINE. MethyZaniZine (Methylophenylarnine).-The deportment of aniline with bromide of methyl resembles its behaviour with the ethyl-compound. The mixture rapidly solidifies into a crystalline mass of hydrobromate of methylaniline. Bromide of methyl being extremely volatile I have used also the iodide which boils at a more con-venient temperature. The action of the latter compound upon aniline is very remarkable the evolution of heat on mixing the two substances being so great that the liquid enters into violent ebul- lition so that unless the substances be mixed gradually the erystal- line hydriodate which is formed immediately is actually thrown out of the vessel.Rilethylaniline when separated from the hydrobromate or hy-driodate appears as a transparent oil of a peculiar odour somewhat DR. HOFMANN different from that of aniline and boiling at 192O; it has retained the properties of aniline in a higher degree than the ethy'fated corn- pound. This substance yields still the blue coloration with hypochlorite of lime although in a less degree than aniline. Its salts are less soluble than those of ethylaniline; they are at once formed in the crystalline state on addition of the respective acids ; the oxalate crystallizes very easily but is rapidly decomposed with reproduction of aniline and probably with formation of oxalate of methyl. The composition of methylaniline is represented by the ex-pression I have established this formula by the analysis of the platinum- salt.This is precipitated as a transparent oil which rapidly changes into pale-yellow crystalline tufts resembling the corresponding aniline-salt but liable to rapid decomposition. The washing must be quickly done for the salt is extremely soluble in water and must be immediately followed by desiccation. Even when very carefully prepared it has become dark by the time it is ready for combustion. It turns instantaneously black if an alcoholic solution of the hydro- chlorate be employed for its preparation. Formula C, H N. H C1 Pt Cl,. I have not attempted to form a dimethylaniline. ACTION OF IODIDE OF METHYL UPON ETI-IYLANILINE. ~et~~y~et~~za~~~~ne .-I have established (Metl72yZet~yZophenylamine) the existence of this compound merely by qixalitative experiments.The mixture of ethylaniline and iodide of methyl begins to crystallize after two days' exposure to the temperature of boiling water. Me-thylethylaniline resembles the preceding base in its odour but has no longer any action upon hypochlorite of lime. I had not prepared a sufficient quantity of the compound for a determination of the boiling-point. The salts of this base are extremely soluble. With the exception of the hgdrobromate I have not been able to obtain a single one in crystals. Even the platinum-salt is not to be obtained in the crystalline form; it is extremely soluble aid separates if very concentrated solutions be eniployed as a yellow oil which does not solidify even after lengthened exposure to the air.This circumstance has prevented me from fixing the composition of methylethylaniline by a number. ON THE VOLATILE ORGANIC BASES. 29? It cannot however be doubted that it is represented by the formula "his compound presents a certain degree of interest inasmuch as the 3 equivs. of hydrogen in the ammonia are replaced by three different radicals namely by methyl ethyl and phenyl. I have prepared however a similar compound containing amyl instead of methyl whose properties permitted an easier analysis. ACTION OF BROMIDE OF AMYL UPON ANILINE. Amylaniline (AmylQp~enylamine.)-A mixture of aniline and an excess of bromide of amyl when left in contact at the common temperature for some days deposits magnificent crystals of hydro-bromate of aniline.Never have I obtained this salt in larger and more definite crystals; although I have seen it deposited of late from a good many solutions. The mother-liquor of this salt is a mixture of amylaniline and bromide of amyl. If aniline be heated in the water-bath with a very large excess of bromide of amyl the whole is converted into hydrobromate of amylaniline which remains dissolved in the excess of bromide. When prepared without the co-operation of heat the amylaniline may be purified simply by separating the crystals of the aniline-salt and distilling the remaining mixture when the bromide of amyl passes over long before the amyl-base begins to volatilize.If the base has been produced by heating the mixture it is necessary after the excess of bromide has been removed to distil the hydrobromate with potassa. 0.2760 grrn. of oil gave 0*8161grm. of carbonic acid and 0.2560 grm. of water. Analysis led to the formula Amylaniline is a colourless liquid possessing all the family features of the group. It is distinguished at the common temperature by tl very agreeable somewhat rose-like odour rather an unusual property for an arnyl-compound; however it does not deny its origin for on heating the base the disgusting odour:of the fusel- alcohol appears but slightly modified. Amylaniline boils constantly at 258* or 54=3 x l8O higher than ethylaniline. This boiling- DR. HOFMANN point is characteristic inasmuch as the elementary group amyl raises the boiling-point of aniline 44O higher than does the insertion of two equivalents of ethyl whose weight is not very inferior to that of the single amyl- equivalent.The amyl-base forms beautiful rather insoluble salts with hydro- chloric hydrobromic and oxalic acids ; when heated with water they form an oily layer on the surface and crystallize only slowly on cooling they have the peculiar fatty appearance which characterizes the crystalline amyl-compounds. The platinum-salt is precipitated as a yellow mass of an unctuous consistence; it crystallizes but very slowly and usually not before partial decomposition has set in. It is on this account that I have not made an analysis of this compound.ACTION OF BROMIDE OF AMYL UPON AMYLANILINE. Diamylaniline (DiamyZophenylamine).-A mixture of amylaniline and bromide of arnyl solidifies after two days’ exposure to the tem- perature of the water-bath. The new basic compound when separated and purified in the usual manner resembles the preceding base especially with respect to odour. Its salts are so insoluble in water that at the first glance one is almost inclined to doubt the basicity of the substance inasmuch as the oil appears to be perfectly insoluble in dilute hydrochloric and sulyhuric acids. However the oily drops floating in the acid solution are the salts themselves which gradually solidify into splendid crystalline masses having likewise the fatty appearance of amyl-substances.The composition of diamylaniline is represented by the expression ~l CIH2IN-CI2{ c ~=(.lo CIrJ Hll}N* ~ Hl c,o Hl1 c12 H I have established this formula by the analysis of the platinum- compound which is precipitated as an oily mass rapidly solidifying into a brick-red crystalline substance. If an alcoholic solution of the lzydrochlorate be employed it is immediately obtained in the crystalline state. When exposed to the heat of the water-bath this salt fuses without however undergoing any decomposition. Formula C, H,? N. M C1. Pt C1 Diamylaniline boils between 275O and 280O; the small scale upon which I had to work prevented me from determining it more accu- rately. Tt is interesting to see how very little the boiling-point is raised by the introduction of the second equivalent of amyl when compared with the effect produced by the insertion of the first.The same remark applies to the ethylanilines. ON THE VOLATILE ORGANIC BASES. ACTION OF BROMIDE OF ETHYL UPON AMYLANILINE AND OF BROMIDE OF AMYL UPON ETHYLANILINE. Amylethylaniline (Amylethylophenylamine).-It remained now only to analyse a basic compound in which the three equivalents of the ammonia-hydrogen should be replaced by three different radicals. found in amylethylanihe a substance similar in composition to me- thylethylaniline but which by its properties admitted of a rigorous analytical examination. Ainylethylaniline is formed without difficulty by the action of bromide of ethyl upon amylaniline.The mixture having been exposed to the heat of the water-bath the conversion was found to be complete after two days. When purified in the usual way amylethyl- aniline forms a colourless oil boiling at 262O only 4 higher than the amyl-base. The properties of this substance are analogous to those of the other bases. It forms a beautiful crystalline hydro- chlorate and hydrobromate ; the platinum-salt is precipitated in the form of a light orange- yellow pasty mass which rapidly crystallizes. The salt fases at looo. By analysis of the platinum-compound I was cnabled to fix without difficulty the composition of the base which is represented by the formula h substance of exactly the same composition as amylethylaniline may be obtained by the action of bromide of amyl upon ethylaniline.ACTION OF BROMIDE OF ETHYL UPON AMMONIA. After the termination of the experiments which have been detailed in the preceding pages there remained no doubt in my mind respect- ing the deportment which ammonia itself would exhibit when subjected in a similar manner to the influence of bromide of ethyl. I had a right to expect in this reaction the consecutive formation of three alkaloids differing from ammonia by containing respectively one two or the three equivalents of hydrogen replaced by ethyl. Experiment has realized this expectation in a very satisfactory manner. I intend to give here only an outline of the process employed and a short description of the substances obtained. Formution of Elhylamine ~~lhylam~o~ia~ of ethyl acts .-Bromide very slowly onzan aqueous solution of ammonia in the cold.Action however takes place; after the lapse of a week or ten days the solu- tion contains a considerable quantity of a hydrobromate in solution. This hydrobromate is a mixture of the salts of ammonia and ethyla- mine the base discovered by M.Wurtz on decomposing cyanate of 300 DR. HOFMANN ethyl with potassa. The presence of this compound may be readily proved by evaporating the liquid after the separation of the excess of bromide of ethyl to dryness in the water-bath in order to drive off alcohol which might have possibly been formed. On adding potassa-solution to the solid residue an alkaline gas is at once evolved which burns with the pale-blue flame of ethylamine.If an alcoholic solution of ammonia be substituted for the aqueous liquid the decomposition proceeds more rapidly. After twenty-foul* hours a copious crystalline precipitate of bromide of ammonium has been deposited. The mother-liquor contains hydrobromate of ethyl- amine and the base in the free state. The action of bromide of ethyl upon ammonia maybe considerably accelerated by raising the temperature to the boiling-point of water. 1 found it convenient to introduce a concentrated solution of ammo-nia with an excess of bromide of ethyl into pieces of combustion-tube 2 feet in length. These tubes after having been carefully scaled before the blow-pipe were immersed to the height of about half a foot into boiling water. The bromide of ethyl enters at once into lively ebullition rises through the supernatant layer of ammo-nia condenses in the upper part of the tube which is cold and falls down to commence again the same circulation.During this process the bromide of ethyl diminishes rapidly in volume. The reaction may be considered terminated as soon as a quarter of an hour’s ebullition ceases to effect a considerable change in the bulk of the bromide. On opening the tube the solution is found to be either neutral or even of an acid reaction and to contain hydrobromate of ethylamine which may be separated by distillation with potassa .with all the properties enumerated by &I. Wurtz. I have not to add a single word to the accurate description of this distinguished chemist and will here only mention that I have analysed a platinum-salt pre- pared with ethylamine which had been obtained by this process.The production of ethylamine in this reaction is absolutely analo- gous to that of ethylaniline; it is represented by the equation H3N + C Hj Br= C H N. HBr. Formation of Diethylamine ~Die~~yla~n~on~a~ .-On treating an aqueous solutionof ethylamine in the same manner with an excess of bromide of ethyl phenomena of a perfectly analogous character are observed. The reaction however proceeds more rapidly and is termi-nated after a few hours’ ebullition. The aqueous layer which assumes a bright yellow colour deposits acicular crystals on cooling consisting of the hydrobromate of a new base for which I propose the name diethylamine or diethylammonia.This base may be readily separated by distillation with potassa when it passes over in the form of a very volatile and inflammable liquid which is still extremely soluble in ON THE VOLATILE ORGANIC BASES. 301 water and of a powerful alkaline reaction. When dissolved in hydro- chloric acid and mixed with a concentrated solution of bichloride of platinum it yields a very soluble platinum-salt which crystallizes in orange-red grains very different from the orange-yellow leaves of the correspondin8 ethylamine-salt. The analysis of this platinum-salt led to the formula C Hi N. H C1. PtC1 establishing the composition of diethylamine which is represented by the formula C,H,,N= C,H, L*:&l N.Formation of Triethylamine ~Tr~e~h~la~~mo~~a~ .-This arises from diethylamine in the same manner as the latter from ethylamine however unlike the deportment observed in the formation of diethyl-aniline the rapidity of the action increases with the progress of the ethylation. A mixture of a concentrated solution of diethylamine with bromide of ethyl solidifies after a very short ebullition into a mass of beautiful fibrous crystals sometimes of several inches in length being the hydrobroniate of a new base for which I propose the name of triethylamine or triethylammonia. This alkaloid may be readily separated by distillation with potassa when it presents itself in the form of a light colourless powerfully alkaline liquid still very volatile and inflammable and also pretty soluble in water but in a less degree than diethylamine.To fix the composition of triethylamine the platinum-salt was subjected to analysis. This is one of the finest salts I have ever seen. It is extremely soluble in water and crystallizes on the cooling of concentrated solutions in magnificent orange-red rhombic crystals which are obtained of perfect regularity and of very considerable size (half an inch in diameter) even if very limited quantities of solution be employed. The analysis of this salt which slightly fused at 1004 leads to the formula C, H, N. HCI PtCl, and shows that triethylamine may be considered as ammonia in which the 3 equivs. of hydrogen are replaced by 3 of ethyl C, H, N= C 131 N. { "c :::i Although not inclined to expect a further action of bromide of ethyl upon triethylamine after the experiments performed with diethylani- line but hoping to obtain in this series more definite results than DR.HOFMANN the latter had yielded I thought it important to appeal once more to experiment. A mixture of an aqueous solution of triethylamine and bromide of ethyl sealed for this purpose into a tube solidified after two hours’ ebullition. The crystals formed in this reaction had the fibrous aspect of the hydrobromate of triethylamine ; still among the transparent prisms some white opaque granular crystals were observed. To gain more positive information the excess of bromide of ethyl was volatilized and the residue distilled with potassa.The base obtained in this manner converted into a platinum-salt and submitted in this form to analysis gave exactly the percentage of platinum con- tained in the salt of triethylamine. Accordingly the base which had distilled over had evidently not been affected any further by the influence of bromide of ethyl. The appearance however of the opaque crystals* indicates that a second compound is formed whose careful study is necessary for the elucidation of this reaction. I am at present engaged with this part of the inquiry. The action then of bromide of ethyl upon ammonia gives rise to the formation of the following series of compounds H Ammonia. . . . H N={ }N. Ethylamine (Ethylammonia) C €3 N={ }N. c4 H Diethylamine (Dieth ylammonia) Trieth ylamine (Triethylarnmonia) It cannot be doubted for a moment that the same cornpounds will be obtained in the methyl- and amyl-series the first terms in each of these series having been actually prepared by M.Wurtz. Nor is it improbable that arsenietted and phosphoretted hydrogen which as is well known imitate to a certain extent the habits of ammonia when * I have since ascertained that these white opaqne crystals are the hydrobromate of a new base of very remarkable properties. The salt in question may be considered as bromide of ammonium in which all the hydrogen equivalents are replaced by a corre- sponding number of ethyl-equivalents. The reaction is much more powerful if instead of bromide of ethyl the iodide be employed.A mixture of triethylamine and iodide of ethyl solidifies at once to a beautiful crystalline salt containing a base which may be considered as oxide of ammonium in which the four hydrogen-equivalents are re- placed by ethyl. This substance is solid and resembles potassa and soda in its general properties. ON THE VOLATILE ORGANlC BASES. subjected to the action of the chlorides bromides or iodides of the alcohol-radicals will yield a series of arsenietted or phosphoretted bases corresponding to the three classes observed with nitrogen. The highly remarkable bodies discovered by M. Paul Thenard appear to warrant this expectation as far as the phosphorus-series is concerned his compound C6 H p corresponding evidently in the phosphoretted methyl-series to triethyl- amine.I mean to extend these researches to the action of the bromides of the alcohol-radicals on phosphoretted and arsenietted hydrogen RELATION OF THE BASES DERIVED PROM ANILINE AND AMMONIA WITH OTHER GROUPS OF ALKALOIDS. It is impossible to leave the history of these compounds without alluding to some remarkable relations existing between these sub-stances and other bodies of an analogous character whose consti- tution is likely to be illustrated by this line of researches. The basic substances derived from aniline when expressed in formulat exclud- ing any peculiar view respecting the mode in which the elements are arranged present a series which is exhibited in*the following synop- tical table Aniline .. . . . . C, H N Methylaniline . . . . C, H W = C, H N + C,H Ethylaniline . . . . C, HI N = C,,H7N + 2C2H2 Methylethylaniline . C, H, Ri = C, H N -t-3 C H Diethylaniline . . . . C, H15N = C, H,N + 4C,H2 Amylaniline . . . . . C, Hi N = C, H7 N + 5 C H2 Ethylamylaniline . . C, H, N = C, H N +-7 C H Diamylaniline . . . . C, H2 N = C, H N + 1OC H This table shows that the alkaloids in question differ from each other by n C H,? the elementary difference of the various alcohols and their derivatives ; we perceive moreover that the series ascends regularly up to the term C, H N + 5 C H, when the compound C, H N +6 C H is wanting ; lastly we miss the terms C, H N + 8 C H and C1 H N + 9 C H,. The first gap might be easily filled by submitting aniylaniline to the action of iodide of methyl methylamylaniline being in fact C, N = C, H N + 6 C H- The other wanting terms cannot be reached from aniline before some of the missing alcohols are discovered.On examining more closely the formuls of the preceding conspec- tus we find several of them represent basic compounds previously 304 DR. HOFMANN known Chemists are acquainted with the beautiful reaction by which Zinin first linked aniline to benzole through nitrobenzole. c12 1% c12 H N 0 c12 H N* U v + Benzole. Nitrobenzole. Aniline. Researches performed in the most different departments of organic chemistry have gradually elicited a series of carbohydrides differing from benzofe by n C B ; and each of these terms when treated with nitric acid and subsequently exposed to the action of reducing agents has yielded its corresponding base.We are now in the possession of the following series of alkaloids derived from hydro-carbons Benzole . . . . c12H6 Toluole . . C,,H = C1,H + C,H Xylole . . . . Cl HI = c, H $-2 c2 H2 Cumole . . . . C18H,,= C,,H + 3C2H Cymole . . . C20H1P=C,,H + 4C,H Aniline . . . . C,,H7 N Toluidine . . . C14H9N = C,,H7N + C,H2 Xylidine" . . . C, H, N = C1 H N + 2C,H Cumidine? . . . C, H, N = C, H N + 3 C H Cymidinet . . . C, H, N = C, H N + 41 C H On comparing the formula of the bases contained in the last table with those representing the alkaloids derived from aniline by the introduction of' methyl and ethyl we find that they exactly coincide.Toluidine has the same composition as methylaniline ; xylidine cuinidine and cymidine are represented by the same formuh as ethylaniline methylethylaniline and die thylaniline. The question then arises are these substances identical or ax they only isomeric nith each other? I have carefully compared the properties of toiuidine with those of methylaniline and also methylethylaniline with cumidine. These substances are not identical but only iso- meric. The most striking dissimilarity we observe in the characters of toluidine and methylaniline. The former is a beautiful crystal-line compound boiling at 198O yielding difficultly soluble perfectly stable salts with alniost all acids and a splendid orange-yellow platinum-salt which may be boiled without decomposition.We are unacquainted with any process by which we could convert this body into aniline. Methylaniline on the other hand is an oily liquid * Chem. SOC.Qu. J. 111 183. t. On Cumidine a new Organic Base by E. Chambers Nicholson ; Chern. SOC. Qu. J. I 2. $ This compound has been partly investigated by Mr. Noad. ON THE VOLATILE ORGANIC BASES. boiling at 1924 whose salts are distinguished by their solubility and by the facility with which they are decomposed aniline being repro- duced. The platinum-salt even when freshly precipitated is of a pale yellow colour which immediately darkens turning perfectly black after the lapse of an hour. Scarcely less striking is the dissiniilarity of cumidine and methylethylaniline although in this case both substances are liquids.For details I refer to Mr. Nicholson's?; paper on cumidine and to what I have stated about methylethylaniline. The quantity of this substance I had at my disposal was not sufficient for a deterniination of the boiling- point; but if we recollect that ethylaniline boils at 204' and that the introduction of methyl into aniline raised its boiling-point about 104 it is evident that methylethylaniline cannot boil at a temperature much higher than 214*,i. e. eleven degrees below 2254 the boiling- point of cumidine observed by Mr. Nicholson. A detailed account of the properties of xylidine has not yet been published; however I have not the slightest doubt that M. Cahours will find them widely differing from those of ethylaniline.Toluidine xylidine and cumidine resembliiig aniline not only in their physical characters but also in their origin from carbohydrides, evidently belong to the class of alkaloids for which I have provision- ally retained the name amidogen-bases while the basic compounds derived from. aniline are either irnidogen-or nitrile-bases. The difference of properties depends upon a difference in the molecular construction as represented graphically by the following table :-Z )'N = Aniline. Cl H N =Toluidine =C1 H N =Methylaniline = C H N. c,,9 H {G:d }N H =Xylidine =C, Hll N =Ethylaniline Cl H N =Cumidine=C, H13N== The view which I propose in the preceding remarks respecting the constitution of toluidine xylidine and cumidine must as yet be considered as a mere hypothesis.It will not however be diflicult to establish it by facts. The action of bromide of ethyl upon these substances will at once decide this question. These bases when subjected to the influence of the bromides will give rise to the for-' * Chem. SOC. QU.J. I 4 5. VOL III*-NOa XI. x 306 DR. HOPMANN mation of a series of bases similar to those which I have obtained from aniline. I may mention that the deportment of toluidine and cumidine in this respect is now being studied by several of niy pupils. There is no difficulty in introducing 1 equiv. of ethyl into toluidine ;the experiments are however not yet sufficiently advanced to aarm also the insertion of the second equivalent.The alka- loid obtained -by acting with bromide of ethyl upon toluicline is represented by the formula Cl 1% N so that we are now in possession of three alkaloids of exactly the same composition namely ethylotoluidine methylethylaniline and cumidine; and here I cannot but allude to the wonderful variety of isomeric compounds to which a continuation of these researches must necessarily lead. We see at a glance that substances of the formala Cl HI N will also be obtained by inserting 1 equiv. of methyl into xylidine by introducing 2 equivs. of methyl into toluidine or by fixing upon aniline the radical (propyl) belonging to the missing alcohol of pro-pionic acid* (metacetic acid). We thus arrive at six alkaloids having all the same numerical formulze but widely differing in their construction.Cumidine . * Methyloxylidine . Ethylotoluidine Dimethylotoluidine Propylanihe . Methylethylaniline This multiplicity of course augments in the Same measure as we Jp A more appropriate name for metacetic acid proposed by Dumas Malaguti and Leblanc (Compt. Rend. XXV 656) as it is the prst acid of the series C H 0 that exhibits the character of a futty acid i. e. in being separated from solution as a layer of oil and in forming salts with the alkalies that have a greasy appearance. ON THE VOLATILE ORGANIC BASES. asceud upon the scale of organic compounds. FOFevery step the number of possible isomeric bases increases by two so that on arriving at the term diamylaniline c, Hi37 N1 being the last member (vide p.298) in the aniline-series which I have examined we find that its numerical formula actually repre- sents not less than twenty different alkaloids which the progress of science cannot fail to call into existence,-a striking illustration of the simplicity in variety that characterizes the creations of organic chemistry. Not less numerous will be the isomerisms in the series of bases derived by the insertion into ammonia of the alcohol-radicals C Hn+l only as soon as the group of these alcohols themselvea shall be more completely known. Ethylamine is isomeric with dime- thylamine ; diethylamine has the same composition as methyloprcl- pylamine a base containing ethyl and propyl the alcohol-radical in the propyl series as dimethylethylamine and lastly as butylamine.Some chemists are actually inclined to consider as such a volatile alkaloid discovered by Dr. Anderson* among the products of the distillation of animal substances and described by him under thc name of petinine. The formula established by Dr,Anderson is but it is not unlikely that on repeating the analysis an additional hydrogen-equivalent will be found The boiling-point of the eorrl-pound (75O) is very much in favour of butylamine. In a similar manner a great number of bases identical in composi-tion with triethylamine will soon be found,-caproylamine methyla-mylamine ethylobutylarnine dipropylamine and a number of others. In conclusion I append a synoptical view of the various basic com- pounds which I have derived from ammonia; this will exhibit the chief results of these researches perhaps better than would a brief recapitulation of the several facts.* Transactions of the Royal Society of Edinburgh XVI 4. x2 !! w c cx TYPE. AMIDOGEN-B ASES. IMIDOGEN-BASES. NITRILE-BASES. H Diethylaniline c4 Hs U (Diethylophenyla-{C H } X. mine) 42 H x Aniline Methylaniline H Methylethylaniline C H C { C H (Methylethglopheny-{ C H } N. 2 +-(Phen ylamine) lamine) ‘t c, H Hs Diam ylaniline c, H5 2 Amylaniline (Amylophenylamine) {2g (Diamylophenyla-mine) (Ethylamylaniline) C H 1 (Ethylamylophenyl.-( C, €31 N. 2 h mine) c12 Ki Ammonia { ~}N Chloraniline { c-,!(E&)} Ethylochloraniline Diethylochloraniline 0 (Diethylochlorophe-(Amine) (Chlorophenylamine) nylamine) M Ethylobromaniline C v Brornaniline { c.,27€l:) } (Bromophenylamine) N* (E~~~~~mopheny-G 3..- 2 w Nitraniline { c4gHi } N. Ethylonitraniline 0 (Eitrophen ylamine) N. (Ethylonitrophenyla-tz 2+ mine) bl tr Ethylamine Diethylamine Trie thylamine {% $ } N. ’ (Ethylammonia) (Diethylammonia) (Trie th ylammonia) c4 H5 {$ H2 -} ” DR. STENHOUSE ON ARTIFICIAL ALKALOIDS. On the Nitrogenated Principles of Vegetables as the Sources Of Artificial Alkaloids. By Dr. John Stenhouse F.R.S.* It is well known that several organic alkaloids such as Aniline Picoline Yetinine &c. are obtained in the dry distillation of coal.Now as coal is of vegetable origin and these organic alkaloids all contain nitrogen it is evident that they must be ultimately derived from the azotized principles contained in the plants from which the coal has been formed. Hence it appears probable that those proxi- mate vegetable principles which are rich in nitrogen such as vegetable albumen fibrinc legumine &c. will when subjected to destructive distillation yield these same alkaloids or bodies closely resembling them in larger quantities than the coal itself,-inasmuch as the powerful agencies to which that substance has been subjected during the course of its formation must have destroyed a large amount of these azotized principles; and moreover the great bulk of it is made up of non-azotizect matter the residue of woody fibre &c, which can contribute nothing to the forniation of the alkaloids.By con-siderations such as these the author was induced to undertake thc researches of which the following is an abstract. Since vegetable albumen fibrine and caseine are very difficult to obtain in a state of purity the experiments were made with those parts of plants chiefly seeds which contain those principles in the greatest abundance. The first experiment was made with the seeds of the common horse-bean (PhaseoZuscommunis),which contain about 22 per cent of azotized matter. The beans were subjected to dry distillation in cast-iron retorts and the distilled products con-densed by a Lie bi g's condenser A strongly alkaline liquid was obtained containing besides other products acetone wood-spirit acetic acid empyreumatic oils tar a very large quantity of ammonia and several organic bases.The crude product was treated with a considerable excess of hydrochloric acid ; the cleay liquid decanted after the tar had settled to the bottom; the tarry residue treated several times with water containing hydrochloric acid ;the several acid liquids mixed and the whole boiled for a couple of hours. By this treatment the acetone wood-spirit and a large proportion of the empyreumatic oils were either driven off or separated by con- version into resinous matter. The acid liquid was then filtered through charcoal to separate the resins and afterwards mixed with lime or soda and distilled. The distillate contained a large quantity of ammonia together with oily bases the amount of the latter being greatest in the first portions which passed over The oily liquid was separated from the ammoniacal solution by means of a pipette; neutralized with hydrochloric acid whereby the neutral oils mixed with the organic bases were left undissolved and could be separated Phil.Trans. 1850 I 47. DR STENHOUSE ON THE NITROGENATED by filtration and the solution supersaturated with carbonate of soda and distilled in a large retort. The oily bases again passed over together with a quantity of ammoniacal liquid from which they wcre separated by the pipette. An additional quantity was obtained from the weak alkaline liquid which passed over at the latter part of the first distillation by neutralizing that liquid with hydrochloric acid concentrating by evaporation supersaturating with carbonate of soda and again distilling.The oily bases obtained by these operations were again rectified with water to purify them from the resinous matter which still remained ;then repeatedly agitated with strong potash-solution which dissolved out the remaining portions of ammonia and formed a solution which could be separated from the oily liquid by means of a funnel; and lastly dehydrated by repeated agitation during several days with fused hydrate of potash and sub- sequent distillation The first two-thirds of the oily distillate mere colourless; the remainder had a yellowish colour but was likewise rendered colourless by repeated rectification.The boiling-point varied considerably during the distillations showing that the oily liquid obtained was a mixture of different bases. An attempt was therefore made to separate these bases by fractional distillation. The liquid began to boil at 108O C. at which point a small portion of a transparent colourless oil passed over. The thermometer then rose quickly to 120° and from thence ta 1303,at each of which points small portions were collected Between 150° and l5s0 the boiling point remained stationary for a con-siderable time and a considerable quantity of oil then distilled over ; about the same quantity mas collected between 160° and 165O. The boiling-points of the last portions varied between 165O and 220O.The products of these different distillations were again repeatedly rectified and by this means bases were obtained corresponding more closely with those points at which the thermometer remained sta-tionary during the first distillation. These bases though differing considerably in their boiling-points nevertheless resemble each other very closely in their other cha-racters. They are colourless transparent oils with strong refracting power lighter than water and having the peculiar pungent slightly aromatic odour which is characteristic of this class of bodies. The &dour remains on the hands and clothes for a long time and is strongest and most pungent in those bases which are most volatile. They have a hot taste not disagreeable in a state of dilution and resembling that of oil of peppermint.The bases which distil over at low temperatures are tolerably soluble in water,-at any rate more ctoluble than those whose boiling-points are high. They all dissolve in every proportion in alcohol and ether. They exhibit strong alkaline reactions with turmeric and reddened litmus-paper emit copious fumes with hydrochloric acid and neutralize acids per-fectly generally farming crystallizable salts With the chlorides of PRINCIPLES OF VEGETABLES. 31 1 gold platinum and mercury they form double salts soluble in water to nearly the same extent as the corresponding arnmoniacal salts. They precipitate ferric and cupric salts the precipitate in the latter case being easily soluble in excess and yielding a deep blue solution.They do not alter by partial exposure to the air but if exposed to a strong light they turn yellow especially those which boil at the higher temperatures. Nitric acid converts them into yellow resins but without forming carbazotic acid. With hypochlorite of lime they form brownish resiiis but give no trace of aniline. When boiled for a few minutes in a retort they gradually become coloured though the liquid which distilled over was colourless at first. At the close of the distillation a small quantity of resinous matter remained in the retort. The quantity of these bases obtained was not sufficient to yield any very definite analytical results. It is not that the proportion of bases yielded by beans and other seeds is leas than that obtained from animal substances; on the contrary it is equal to that obtained from bones and much greater than that yielded by coal but we have not the advantage-as in the case of bones and coal-of being able to procure the crude oils in large quantity as the waste-products of manufacturing operations ; and consequently the chemist is obliged to distil the seeds on purpose an operation requiring very large apparatus and not conveniently conducted in the laboratory.The base which boiled between 150° and 155O was found by analysis to contain about 74.7 per cent of carbon and 7.98 of hydrogen numbers which nearly correspond with the formula This formula was likewise confirmed by the analysis of the platinum-salt. The cornbination of this base in the anhydrous state with hydrochloric acid is attended with great evolution of heat.The hydrochlorate is very soluble in water and crystallizes in slender prisms. Similar compounds are formed with sulphuric and nitric acid. The platinum-salt crystallizes in four-sided prisms arranged in stars of a deep yellow colour. The gold-salt is very soluble in hot water and crystallizes in pale yellow needles on cooling. The composition of this base approaches very closely to that of ni- cotine C, H N ; but its properties agree more nearly with pico- line the base discovered by Dr. Anderson in coal-tar. It has however a higher boiling-point and is less soluble in water than the latter. It is lighter than water has a peculiar and slightly aromatic odour and a hot taste resembling peppermint; dissolves in every proportion in alcohol and ether ; and remains colourless though kept in an imperfectly stoppered bottle provided it be not exposed to a strong light.It takes fire readily and burns with a bright smoky flame. Three of the bases with which the preceding compound wm accom- DR. STENHOUSE ON THE NITROGENATED panied were likewise analysed and gave the proportions of carbon and hydrogen stated in the following table (a) is the base or rather mixture of bases which boiled between 160Oand 165O; (b) between 165O and 170O; (c) between 200°and 210O. a 6. C. Carbon . 74.08 75.42 75.63 Hydrogen b . 8.06 8.52 8.73 It is rather remarkable that the amount of carbon and hydrogen in these bases or rather mixtures of bases does not differ more considering the great difference in their boiling points.They all form double salts with gold and platinum; those which contain the less volatile bases however crystallize less readil and are more contaminated with resinous matter. Their solubi t'ty in water like- wise diminishes as the boiling-point rises. They all appear to possess equally strong basic properties. More complete investigation was precluded by the great difficulty of procuring these bases in sufficiently large quantity. The next substance subjected to destructive distillation was oif-cake or rather the dried seeds of Linum usitatissimunz from which the fat oil had been expressed. This substance was selected as the type of that numerous class of plants in which the starch of the Grauzinncea! is replaced by oil.Of these the poppy rape and mustard are the best known they are all very rich in albumen. About 2 cwt. of oil-cake was broken into moderate-sized pieces and distilled in the same apparatus as had been used for the beans. The liquid product was smaller in quantity than that obtained from the beans it had an extremely unpleasant odour and contained acetone acetic acid a large proportion of tar and empyreumatic oils and a considerable quantity of ammonia The quantity of organic bases was however not more than one-third of that obtained from the beans. The deficiency may in all probability be attributed to the higher temperature required for the distillation of the oil-cake inasmuch as the volatile alkaloids are decomposed at high tempe- ratures with evolution of ammonia.The bases obtained from the oil-cake were separated and purified by the process already described in the case of the beans. They consisted of a mixture of basic oils different from those yielded by coal or by bones inasmuch as they contained neither aniline nor quinoline. Their odour was different from that of the bases obtained from beans but they resembled the latter closely in their basic pro-perties and in the characters of their Palts. On the whole it seem probable that some of the bases of the two groups may be identical. The grain of wheat (Tri&cum hybernum) which was chosen as the type of the Graminace yielded by dry distillation products very digwent from those previously described-the distillate being strongly acid from thr presence of a large quantity of acetic acid derived PRINCIPLES OF VEGETABLES.from the starch in the grain. Acetone and wood-spirit were likewise present in considerable quantity. The distillate likewise contained a large quantity of ammonia but the proportion of organic bases was very small somewhat less than from oil-cake. These organic bases were very similar to those obtained from the preceding sources but appeared to be more volatile they contained neither aniline nor quinoline. Feat from the moors near Glasgow when subjected to destructive distillation yielded a distillate which was nearly neutral and contained a large quantity of acetic acid besides acetone and wood-spirit.The acid distillate was mixed with hydrochloric acid and boiled to drive off the acetone and wood-spirit-whereupon as the liquid cooled the tarry matter separated as a semi-solid crust on the surface and could be easily removed. The clear liquid was then supersaturated with carbonate of soda and distilled. An ammoniacal liquid passed over mixed with a considerable quantity of oily bases which were separated as in former cases. The quantity of these bases was much greater in proportion to the ammonia thau in the distillate from the linseed-cake probably because they distilled over at a lower tenipe- rature. They strongly resembled the preceding groups and contained neither aniline nor quinoline.Wood-The rough distillate of beech oak ash and other hard woods obtained in the manufacture of pyroligneous acid (for which purpose the stems and thicker branches are exclusively employed) was found to contain scarcely a trace either of ammonia or of organic alkaloids. Hence it would appear that the stems of trees are almost destitute of azotized matter presenting in that respect a striking contrast to peat. This difference may perhaps throw some light on the origin of coal. For coal when subjected to destructive distil- lation yields a large quantity of azotized products and must therefore have been formed from vegetable matter rich in nitrogen. Hence the theory which regards it as produced by the submersion of peat- bogs appears to be more probable than that which attributes it to the submersion of trees.It is true that the bases derived from peat are not the same as those from coal; but on the other hand it mast be remembered that plants of Merent families when submitted to dry distillation yield different groups of volatile bases thus plants of the indigo tribe yield ammonia and aniline ;tobacco-leaves yield ammonia an& nicotine &c. &c. Hence the difference in the distil- lation-products of peat and coal may perhaps be ascribed to the difference between the plants from which the coal-strata have been formed and those of which the peat-mosses of the present day are composed. Formatim of Organic Bases $-om Azotized ?Tegetable and Animal Xlcbstances otherwise than by Destructive Distillation 1.By treating them with alkaline Zeys.-A quantity of beans was introduced into a large distillatory apparatus and boiled with caustic I)R STENHOUSE OF THE NITROGENATED soda. The beans were soon converted into a slimy dark-coloured pulp which frothed up considerably and rendered the distillation very troublesdme. By carefully rectifying the crude distillate a clear strongly alkaline liquid was obtained which contained a large quantity of ammonia a sinall quantity of an aromatic oil having an agreeable odour and a notable quantity of organic bases. These bases were separated in the same manner as in former instances. Theywere similar to those obtained by destructive distillation but the author could not positively decide as to whether they were identical.Oil-cake yielded similar results and hence we may conclude that the same would be the case with the azotized portions of other plants when similarly treated. The liver of an ox boiled with caustic soda yielded a strongly alkaline liquid from which a small quantity of oily bases was obtained but not sufficient to determine their nature. 2. By the aid of Sulphuric acid-A small quantity of beans was digested with dilute sulphuric acid care being taken not to let the action proceed so far as to cause the evolution of sulphurous acid. The acid liquid supersaturated with carbonate of soda and distilled yielded an ammoniacal distillate containing organic bases similar to those already described. Hence it is probable that animal substances similarly treated would likewise yield organic bases.3. By Putrt$action.-A quantity of horse-flesh previously ex-hausted of soluble matters by long-continued boiling was moistened with water and left to itself in a warm place for a month. When it had reached a somewhat advanced state of putrefaction it mas treated with water containing hydrochloric acid as long as anything was dissolved out and the acid liquid concentrated filtered super- saturated with carbon of soda and distilled. An alkaline liquid passed over from which by repeated rectification with caustic soda a light oily fluid was obtained consisting of several organic bases mixed together. It had an aromatic and not unpleasant odour was very soluble in water strongly alkaline and formed crystalline salts with acids.Contrary to expectation however it was found to be quite free from aniline. The quantity of organic bases obtained from this source was not so great as might have been expected ;being much less than that produced by destructive distillation. Perhaps however if the putrefaction were suffered to go on for a longer time-till in fact the flesh should be completely decomposed- the quantity of bases thereby produced might be greater than that resulting from destructive distillation. Considering indeed the very gradual nature of the putrefactive process it may possibly be found the most advantageous that can be adopted for the preparation of these alkaloids on tlie large scale. 4. Orgarzic bases from Guano.-A quantity of Peruvian guano very dry of pale yellow colour and emitting a comparatively feeble odour was distilled with water and an excess of quick lime.The PRINCIPLES OF VEGETABLES. distillate which was strongly ammoniacal was saturated with hydro- chloric acid evaporated to one-third of its bulk then supersaturated with carbonate of soda and re-distilled. The liquid which passed over contained a small but appreciable quantity of oily bases which appeared to be more easily soluble in water than those obtained from the preceding sources. Bases from Lycopodium-A quantity of lycopodium (the repro- ductive matter of lycopodiaceze) boiled with strong caustic soda evaporated to dryness and distilled yielded a considerable quantity of ammonia and a basic oil which was but slightly soluble in water and had a pecnliar very penetrating odour like that of the borage plant.It neutralized acids completely but in other respects did not resemble the bases previously mentioned. The same oil was obtained by destructive distillation of the plant ; towards the end of the operation however another oily liquid was obtained having an odour more like that of the bodies previously described. This result with lycopodium affords another instance of the fact that plants of different natural families yield different groups of volatile organic bases. Bases from Pteris aquiZina.-The stems and leaves of the com-mon fern (P. apuiZina) being subjected to distillation yielded a very alkaline liquid containing ammonia and a tolerably large quantity of organic bases thc odour of which was very much like that of the bases obtained froni beans and from linseed.From the facts above detailed it seems to follow that ‘I Whenever ammonia is produced in Zurge quantity from complex animal or vegetable substances it is always accompanied by the formation qf volatile organic buses.” If therefore researches similar to the above are actively prosecuted and especially if the seeds and leaves of the various genera of plants are subjected to similar processes it seems not unreasonable to expect that the number of volatile organic alkaloids will ere long be considerably increased. Another inference which seems to follow from these experiments is that the nitrogenous principles of these plants viz.vegetable albumen caseine fibrine &c. though very analogous to the corre-sponding principles of the animal kingdom are not identical with them; otherwise the products of decomposition would be the same. In conducting the destructive distillation of animal and vegetable substances it is important to operate at as low a temperature as possible; for if the heat be raised too high the organic bases are almost totally destroyed ammonia being then the only alkaline product. It is highly probable that in many cases the ammonia obtained in the distillation of animal and vegetable substances is really derived from the destruction of orgaiiic bases; for these organic bases are more coxplex in their structure than ammonia; and the most stable of them when passed once or twice through a tube filled with red-hot charcoal are almost entirely converted into MR JOULE ON THE that alkali; and even when organic bases are strongly heated in contact with potash or soda or when their aqueous solutions are simply boiled for any length of time they always undergo partial decomposition ammonia being an invariable product.On the Mechanical Equivalent of Meat. By J. P.Joule F,C.S.* Opinions have long been divided between two hypotheses respect- ing the nature of heat,-the one regarding it as a peculiar substance the other as the cffect of motion among material particles. The latter hypothesis appears to be most in accordance with the develop- ment of heat by friction-a phenomenon first accurately investigated by Count Rumford who showed that the very great quantity of heat excited in the boring of cannon could not be ascribed to a change in the calorific capacity of the metal and thence concluded that it was due to the motion in the particles communicated by the borer.cc It appears to me,” he remarks extremely difficult if not I‘ impossible to form a distinct idea of anything capable of being excited and communicated as the heat was communicated in these experiments except it be rnotion.”T In the same paper Count Rumfordmakes an estimate of the quantity of niechanical force required to produce a certain amount of heat-showing in fact that the friction produced by the power of one horse acting for two hours and a half will generate heat sufEcient to raise 26-58 pounds of water from 32O to 212O F.Now the power of a horse is estimated by Watt at 33,000 foot-pounds,$ and there- fore if continued for two hours and a half will amount to 4,950,000 €oat-pounds. Hence it is easily calculated that the heat required to raise a pound of water lomust be equivalent to the force repre-sented by 1034 foot-pounds. This estimate of the force is rather too high no account having been taken of the heat communicated to the containing vessel or of that which was lost by dispersion during the experiment. About the end of the last century Sir Humphry Davy showed that when two pieces of ice were rubbed together in vacuo part of them was melted although the temperature of the receiver was kept below the freezing-point.This experiment was the more decisive in favour of the doctiine of the immateriality of heat inasmuch as the heat-capacity of ice is much less than that of water. It was there- fore with good reason that Davy drew the inference that <<the immediate cause of heat is motion and the laws of its communi- * Phil. Trans. 1850,I 61. 1. Phil. Trans. (abridged) XVIII 286. $ A foot-pound is the force expended in raising a pound-weight one foot high in a minute. MECHANICAL EQUIVALENT OF HEAT. cation are precisely the same as the laws of the communication of motion.”* Dulong discovered the remarkable fact that :-‘cEqual volumes of all elastic fluids at the same temperature and under the same pressure if compressed or dilated suddenly to the same fraction of their volume disengage or absorb the same absolute quantity of heat .”-/-This law is of the utmost importance in the development of the theory of heat inasmuch as it shows that the calorific effect is under certain conditions proportional to the force expended.The researches of Dr. Faraday on the relations between light heat electricity magnetism and chemical force all tend to show that the so-called imponderables are merely exponents of different kinds of force. Mr. Grove and M. Mayer have likewise advocated the same views. The earlier investigations of Mr. Joule in connection with this matter are described in his Memoir as follows (‘My own experiments in reference to the subject were com-nienced in 1840,in which year I communicated to the Royal Society niy discovery of the law of the heat evolved by voltaic electricity a law from which the immediate deductions were drawn 1st.That the heat evolved by any voltaic pair is proportional c&mis paribus to the electromotive force;$ and 2nd. That the heat evolved by the combustion of a body is proportional to the intensity of its affinity for oxygen. I thus succeeded in establishing relations between heat and chemical affinity. In 1843 I showed that the heat evolved by magnetic electricity is proportional to the force absorbed and that the force of the electromagnetic engine is derived from the force of chemical affinity in the battery or force which would otherwise be evolved in the form of heat.From these facts I considered myself justified in announcing that the quantity of heat capable of increasing the temperature of a pound of water by one degree of Fahrenheit’s scale is equal to and may be converted into a mechanical force capable of raising 838 lbs. to the perpendicular height of one foot.”$ In a subsequent paper read before the Royal Society in 1844 I endeavoured to show that the heat absorbed and evolved by the rarefaction and condensation of air is proportional to the force evolved and absorbed in those operations. (1 The quantitative relation between force and heat deduced from these experiments is almost identical with that derived from the electro-magnetic experiments just referred to and is confirmed by the experiments of M.Seguin on the dilatation of steam.”fi “From the explanation given by Count Rumford of the heat * Elements of Chemical Philosophy p. 94. $ Phil. Mag. XIX 225. .f. Mem. Acad. Sec. X 188. 5 Phil. Mag. XXIII 441.’ 11 Phil Mag. XXVI 375,379. TI Compt Rend XXV 421. Mk. JOULE ON TBE arising from the friction of solids one might have anticipated %w a matter of course that the evolution of heat would also be detected in the friction of liquid and gaseous bodies. Moreover there were many facts such as for instance the warmth of the sea after a few days of stormy weather which had long been attributed to fluid friction. Nevertheless the scientific world pre-occupied with the hypothesis that heat is a substance and following the deductions drawn by Pictet from experiments not sufficiently delicate have almost unanimously denied the possibility of generating heat in that way.The first mention so far as I am aware of experiments ill which the evolution of heat from fluid friction is asserted was in 1842 by M. &layer,* who states that he has raised the temperature of water from 12"to 13O C. by agitating it without however indi- cating the quantity of force employed or the precautions taken to seciire a correct result. In 1843 I announced the fact that 'heat is evolved by the passage of water through narrow tubes,'? and that each degree of heat per pound of water required for its evolution in this way a mechanical force represented by 770 foot-pounds.Subsequently in 18452 and 1847,$ I employed a paddle-wheel to produce the fluid friction and obtained the equivalents of 781.5 782.1 and 787*6respectively from the agitation of water sperm-oil and mercury." Results so closely in accordance with one another and with those previously derived from experiments with elastic fluids and the electro-magnetic machine indicated beyond doubt the existence of an equivalent between force and heat; but still it appeared of the highest importance to obtain that relation with greater accuracy. With this view fresh experiments were made of which the following is an abstract The apparatus employed for producing the friction of water con- sisted of a brass paddle-wheel furnished with eight sets of revolving arms working between four sets of stationary vanes.This revolving apparatus was firmly fitted into a copper vessel in the lid of which were two necks one for the axis to revolve in without touching the other for the insertion of a thermometer. A similar apparatus but made of iron of smaller size and having six rotatory and eight sets of stationary vanes was used for experiments on the friction of mercury. The apparatus for the friction of solids consisted of a vertical axis carrying a bevelled cast-iron wheel against which a fixed bevelled wheel was pressed by means of a lever; the wheels were enclosed in a cast-iron vessel filled with mercury the axis passing through the lid. In all these arrangements motion was given to the axis by the descent of leaden weights suspended by strings from the axes of two wooden pulleys these axes being supported on * Ann Ch.Pharm. XLI. -t. Phil. Mag. XXIII 442. $ Phil. Mag. XXVIII 205. 5 Phil Mag. XXXI 1'13i afso Compt Rend XXV,309. MECHANICAL EQUIVALENT OF HEAT. 319 friction-wheels. The pulleys were connected by fine twine passing round their circumferences with a wooden roller which by means of a pin could be easily attached to or removed from the axis of the frictional apparatus. The mode of experimenting was as follows :-"!he temperature of the frictional apparatrxs having been ascertained and the weights wound up with the assistance of a stand provided for the purpose the roller was fixed to the axis. The precise height of the weights above the ground having been determined by means of graduated vertical slips of wood the roller was set at liberty and allowed to revolve till the weights reached the floor.The roller was then removed to the stand the weights wound up again and the friction renewed. After this had been repeated twenty times the experiment was concluded with another observation of the temperature of the apparatus. The mean temperature of the apartment was determined by observations made at the commencement middle and determina- tion of each experiment. Previously to or immediately after each experiment an observation was made of the effect of radiation and conduction to or from the atmosphere in depressing or raising the temperature of the friction apparatus.In these trials the position of the apparatus the quan- tity of liquid contained in it the time occupied the method of observing the thermometers the position of the experimenter-in short everything with the exception of the apparatus being at rest- was the same as in the experiments in which the effect of friction was observed. In the experiments with water a correction was made for the quantities of heat absorbed by the copper vessel and the paddle- wheel ; and in the experiments with mercury and cast-iron the heat- capacity of the whole apparatus was determined by ascertaining the heating. effect which it produced on a known quantity of water in which it was immersed. In all the experiments corrections were likewise made for the velocity with which the weights came to the ground and for the quantity of force expended in overcoming friction and the rigidity of the strings.The thermometers with which the temperatures were observed had their tubes calibrated and graduated by Regnault's method and were capable of indicating a difference of temperature as small as &of a degree of Fahrenheit's scale. Friction of water.-A force of 6067.14 foot-pounds was found to raise the temperature of 9747'0.2 grains of water by OO.563209 which is equivalent to 7*842299pounds of water raised lo. Con-seauentlv 6067*114= 773.64 foot-pounds, 7-842299 is the force which according to this determination is equivalent to loFahr. in a pound of water. 320 MR. JOULE ON THE MECHANICAL EQUIVALENT OF HEAT.Friction of mercury.-In one set of experiments with the mercurial apparatus a force of 6077,939 foot-pounds was found to generate heat sufficient to raise the temperature of 7'85505 pounds of water one degree ;the equivalent thence deduced is G077'939 = 773.62 7.85504 A second series of experiments with the same apparatus but smaller weights gave for the equivalent 2100*272= 776.303 2.70548 Friction of cast-iron.-A force of 59800955 foot-pounds generated heat suffcient to produce a rise of loin 7.69753 pounds of water. The equivalent thence deduced is Another series of experiments with smaller weights gave In these last experiments the friction of the cast-iron wheels produced a considerable vibration in the frame-work of the apparatus as well as a loud sound; it was therefore necessary to make allowance for the quantity of force expended in producing these effects.The following table contains a summary of the equivalents determined as above; in the fourth column the results are given with the correction necessary to reduce them to a vacuum. Material employed. Equivalent in air. Water . . . . 773.640 Equivalent i.n 'oacuo. 772*692 Mean. 772.692 Mercury . . 773.762 ¶I . . . 776.303 Castiron . . . . 776.997 JY . . . 774880 '176*045774.930 774*987 The equivalent 772.692 is regarded by the author as the most correct; but even this he observes is probably a little too high because even in the friction of fluids it is impossible entirely to avoid vibration and the production of a slight sound.The conclusions to be deduced froin all the experiments above- described are 1. Thut the quantity of heat produced by the friction of bodies whether solid or liquid is always proportional to the force expended. 2. That the quantity of heat capable of increasing the temperature of n pound of water (weighed in vacuo and faken at between 55O and 60°) 6y loFAHR., requiresfGr its evolution the expenditure of a mechanical force represented by the fall of 772 Ibs. through the space of onefoot

ISSN:1743-6893    

DOI:10.1039/QJ8510300257

出版商:RSC    

年代:1851

数据来源: RSC