摘要:

THE QUARTERLY JOURNAL OF THE CHEMICAL SOCIETY November 5 1849. The President in the Chair. The following donations to the Society’s Library since the last Meeting were announced. <‘ lteport of the Smithsonian Institution,” and ‘< Smithsonian Contri- butions to Science,” Vol. I. from the Institution. “Contributions to the Science of Agriculture,” by J. F. W. Johnstone M.A. from the Author. ‘‘De Saliva,” by Nicolaus Jacubowitsch,” and cc Die Diagnostik ver-dachtiger Flecke in Criminalfallen,” by Carl Schmidt, from Dr. Schmidt. On the motion of Gases,” Part II. by Thomas Graham Esq. from the Author. ‘‘ Proceedings of the Royal Society of Edinburgh,” Nos. 33 and 34 from the Society. Mr. Henry Sugden Evans was elected a Fellow of the Society.The following Papers were read XX1X.-On a new series of Organic Bodies containing Metals and Phosphorus. By E. FRANKLAND, Ph. D. Since submitting to the Society niy Memoir on the Action of Zinc upon Iodide of Ethyl I have been engaged in investigating the action of the same metal upon the corresponding methyl compound; the results which I shall communicate in a future paper are nearly analogous methyl gas is disengaged and a white crystalline residue ?remainsin the decomposition-tube. The peculiar behaviour of this residue with water which decomposes it producing brilliant flame VOL. IIn-NO. VIII. X DR. FRANKLAND ON A and causing the evolution of pure light carburetted hydrogen induced me to study it more closely.When the substance was subjected to distillation in an apparatus filled with dry hydrogen a colourless pellu- cid liquid possessing a peculiarly penetrating and exceedingly nanseous odour condensed in the receiver ; this liquid spontaneously inflames on coming in contact with air or with oxygen burning with a brilliant greenish-blue flame and forming dense clouds of oxide of zinc; its vapour mixed with a large excess of methyl and light car-buretted hydrogen does not inflame spontaneously but on being ignited burns with the characteristic flame depositing upon cold surfaces held within it a black crust of metallic zinc surrounded by a ring of oxide. This encrustation is easily distinguished from arsenic by its ready solubility in dilute hydrochloric acid with the simultaneous evolution of hydrogen and by the solution thus obtained affording no reaction with sulphuretted hydrogen.The vapour of this compound is highly poisonous producing shortly after its incautious inhalation all the symptoms of poisoning by zinc. It decomposes water with as much violence as potassium the small tube containing a few drops of the liquid becoming red hot under water ;the products of this decomposition are oxide of zinc and two equivalents of pure light carburetted hydrogen from which it is evident that the body in question is composed of 1 equiv. methyl and 1 equiv. zinc (C H Zn) for C H Zn +HO =Zn 0+2(C H2) and this view is confirmed by direct analysis. It is highly probable that this body which for the present I propose to call Zincmethyl plays the part of a radical combining directly with oxygen chlorine iodine &c.but my experimerrts are not yet sufficiently complete to enable me to state this positively. A corresponding compound containing ethyl is also formed during the decomposition of iodide of ethyl by zinc this body which may be conveniently named Zincethyl is less volatile and possesses some- what weaker affinities than Zincmethyl; on decomposition with water it yields oxide of zinc and methyl gas; C H Zn +HO =Zn 0 + 2(C H3). The existence of this body satisfactorily explains the action of water upon the crystalline compound formed by the de- composition of iodide of ethyl by zinc as well as the action of these latter bodies upon each other in the presence of water and of al-cohol; whilst in the decomposition of ethyl by zinc in presence of ether there can be little doubt that the zincethyl dissolves in the anhydrous ether without decomposition and is transformed on the subsequent addition of water into oxide of zinc and 2 vols.of methyl thus showing that the presence of the latter body in the gaseous NEW SERIES OF ORGANIC BASES. 299 products of the decomposition is not owing to the decomposition of the elements of water from the ether as was suggested in my former memoir These facts render it highly probable that in the decomposition of iodide of ethyl by arsenic and by tin mentioned in the memoir above alluded to these metals combine with the ethyl generating com-pound radicals analogous to cacodyl; in fact the product of the decomposition by arsenic exhales a most insupportable odour greatly resembling that which is so characteristic of this radical whilst a similar decomposition of iodide of methyl would probably yield cacodyl itself.I have also found that the iodides of ethyl methyl &c. are readily decomposed by phosphorus and as no gases are evolved it is not improbable that a series of bases containing phosphorus ana-logous to that of Paul Thenard C 13 P= (C H3) 3P may result from this reation. The existence of hydrogen compounds of arsenic antimony and tellurium and the substitution of ethyl and methyl for hydrogen in the new bases of Wurtz point out the striking similarity between the respective functions of these radicals and of that element and taken in connection with the above facts seem to warrant the expectation that most if not the whole of the following compounds may be obtained.Those marked with an asterisk are already known. H~~~~~ Methyl series Ethyl series. Rutyryl series ZnH ZnC,H,* ZnC,H,* ZnC,H7 As H As (C H,),* As ( C H5J2As (C H7I2 Sb H,* Sb (C H,),,Sb (C H,) Sb (C Hj, P Ha* P (C,H3)3* P (c,H513 P (C H7)3 With a view to obtain these bodies most of which will probably be found to play the part of radicals and combine directly with oxygen chlorine &c. I have made several preliminary experiments which seem to promise success ; these together with the complete description of the chemical relations of zincmethyl and zincethyl I will communicate as early as the peculiar difliculties attending their investigation will all0 w . Dr. Hofmann exhibited a specimen of the zincmethyl he had obtained from Dr. Frankland and demonstrated its spontaneous in- flammability. x2

ISSN:1743-6893    

DOI:10.1039/QJ8500200297

出版商:RSC    

年代:1850

数据来源: RSC

摘要:

300 DR. HOPMANN ON THE XXX.-Researches on the Volatile Organic Bases. By DR. A. W. HOFMANN. v. ON THE -4CTION OF ACIDS AND BASES UPON CYANILINE. IN describing the preparation of the salts of cyaniline I had repeated occasion to allude to the rapid decoinposition of this base under the influence of acids. I mentioned at that time that under these circumstances aniline was reproduced but I had not examined minutely the other products of the same reaction. To complete the study of cyaniline it became necessary to investi-gate carefully the phenomena of this decomposition. My attention was more particularly directed to this subject by the remarkable results which in the meantime had been obtained in the investigation of other organic cyanogen-compounds and by the hope of con-firming the somewhat unexpected formula which had been elicited in the study of this substance.Action of Dilute Acids upon Cyani2ine.-C yaniline dissolves with the greatest facility in dilute hydrochloric acid. By concentrated acid the base is at once converted into the hydrochlorate which like many chlorides is insoluble in the acid. I have mentioned that the best method for obtaining the hydrochlorate is to dissolve the base in the dilute acid and to add immediately fuming acid when the salt is directly precipitated in the form of white scales; but that I had in vain tried to obtain it by concentrating the dilute solution. The crystals deposited on evaporation are found to contain scarcely a trace of cyaniline. Some preliminary experiments pointed out at once the complex nature of this crystalline deposit and a minute investigation proved that it consists of not less than five different compounds which can be separated only with difficulty.To obtain these substances separate froiii each other a sufficient quantity of cyaniline half an ounce was dissolved in dilute hydro- chloric acid and the liquid which assumed a yellow colour evapo- rated on the water-bath. The white crystalline mass thus obtained was washed with cold water by which a portion was dissolved which was found to consist entirely of chloride of ammonium and hydrochlo-rate of' aniiine. The solution possessing in a high degree the remarkable odour whieh I had repeated occasion to mention in former parts of this inquiry was carefully tested for oxalic and formic acids the usual products of the decomposition of cyanogen or VOLATILE ORGANIC BASES.hydrocyanic acid but not a trace of either of these acids could be detected. The residue insoluble in cold water was now repeatedly ex-hausted with boiling water by means of which again a separa-tion was effected leaving a slight crystalline residue whilst the aqueous solution deposited on cooling crystals which were still a mixture of two compounds of which the one was much more soluble in water than the other. The compound left after treatment with boiling water was slightly coloured. It appeared desirable to piirify it farther previously to analysis and as it was found to be soluble in alcohol only with the greatest difficulty I availed myself of benzole which proved to be a better solvent although even this liquid took up a very small quantity.On evaporating the benzolic solution the body separated in shining scales which becarne perfectly pure by washing with alcohol. A portion thus purified was subjected to combustion with protoxide of copper. 0.3446 grm. of substance gave 0,8795 , ,,carbonic acid and 0.1565 , ,,water. Corresponding to the percentage Carbon . 69-60 Hydrogen . . 5.04 numbers which represent the composition of oxanilide as may be seen by the following comparison Theory. Experiment. -14 equivs. of Carbon . . . 84 70.00 69966 6 , , Hydrogen . . 6 5.00 5 -04 1 , ,,Nitrogen . . . 14 11.66 -2 , , Oxygen .. . 16 13.34 -1 equiv. of Oxanilide . . . 120 100.00 The deportment of the substance with reagents removed the last doubt respecting its identity with oxanilide; under the influence of a boiling concentrated solution of potash aniline was evolved oxalate of potash remaining behind. The aqueous solution filtered from the impure oxanilide which as I mentioned had deposited a crop of mixed crystals was evapo- DR. BOFbIANN ON THE rated to dryness together with the crystals on the water-bath. The separation of this mixture was effected with concentrated alcohol which left a yellowish residue and this was found to be insoluble in cold but slightly soluble in boiling water. Deposited from this solvent after boiling with a small quantity of animal charcoal it appeared as a snow-white tasteless inodorous powder.There was no difficulty in recognizing oxamide even by its physical properties and the ready convertibility of the substance into oxalic acid and ammonia both by acids and bases,. precluded the necessity for a combustion. It remained to investigate the compound which had been sepa- rated from the oxamide by means of boiling alcohol. It was depo- sited from this solution partly on cooling partly after concentration in snow-white hair-like flocks of a satiny lustre. One or two crystallizations from boiling water in which these flocks were likewise soluble rendered them pure. This compound was also soluble in ether. It sublimed without decomposition the sublimate being BS light and mobile as precipitated silicic acid.I have prepared this substance four different times. Each prepa- ration was analysed by combustion. I. 0.2153 grm. of substance gave 0.4693 , ,,carbonic acid and 0.0980 , ,,water. 11 0.3767 , ,,substance gave 0.8030 , ,,carbonic acid and 0.1615 , ,,water. 111. 0.4083 , ,,substance gave 0.8706 , ,,carbonic acid and 0.1781 , ,,water. IV. 0.3811 , ,,substance gave 0.8124 , ,,carbonic acid and 0.1676 , ,,water. V. 0.4573 , ,,substance* gave 0.5380 , ,,platinum. Percent age I. 11. 111. IV. V. Carbon . . 59.45 58-13 58.15 58.13 - Hydrogen Nitrogen . . 5.05 - 4.76 - 4-84 I 4.88 - -16.71 * The same preparation as that used in Analysis IV. 303 VOLATILE ORGANIC BASES.This percentage represents the formula c H N 0,or C16 H N 04 which requires the following values Mean Qf Theory. Experiments. 16 equivs. of Carbon . . . 96 58-53 58.46 8 , , Hydrogen . . 8 4-87 4.88 2 , , Nitrogen . . 28 17.07 16.71 4 , ,,Oxygen . . . 32 19.53 I 264 100.00 The mean of the analyses agrees much better with theory than the different experiments accord with each other. But this may readily be explained by the long and tedious series of operations which the compound has to undergo previously to analysis. It is obvious that the specimen employed in the first analysis must have still contained a little oxanilide whilst perhaps some oxamide may have adhered to the latter specimens. The circumstances however under which this compound is formed and the products into which it is decomposed by acids and alkalies leave no doubt respecting its composition..It is evidently a double compound of Oxanilide and Oxamide,* (Oxani-lamide) c, H N 04 = c, H N c 0,;H,N c 02 corresponding in composition to an analogous compound of car-banilide and carbamide,? which as I have shown in my last commu- nication to the Society is formed in so great a variety of ways. * I have tried to obtain some farther confirmation of this formula by adopting another method of preparing this singular compound. Oxamethane (oxamate of ethyl) yielding when treated with ammonia two equivalents of oxamide it appeared very probable that by substituting aniline for ammonia the desired compound might be formed according to the following equation C H C O, H,N C 0,+ C, H N =C H 0 + C, H N C 0,; HgN C 0 L-/ -V-J Oxamethane.Alcohol. Oxanilamide. I have not been able to verify this equation by experiment. Aniline appears to act but slowly upon oxamethane I have not however sufficiently varied the experiment ; it is possible that by continued action under pressure by a certain temperature or in the presence of alcohol and ether the decomposition may be effected. Incidentally to this experiment I have tried the action of aniline upon oxalic ether. Oxanilide is9formed in this case but likewise only very slowly. t Carhanilamide having the same composition as urea in which ammonia is replaced by aniline and being formed under circumstances analogous to those which give rise to the formation of ordinary urea I felt inclined when first (Chem.SOC. Mem. XI. 300) I 3M DB. HOFMANN ON THE Carbanilamide . . C, H N C 0;H,N C 0. Oxanilamide . . C1 H N C 0,; H,N C 0,. Oxanilamide is soluble in a concentrated solution of potassa with which it cannot however remain in contact m7ithout deconiposition. The solution is perfectly transparent and acids precipitate un-changed oxanilamide ; after a short period however varying with the concentration of the solution and the temperature the liquid becomes turbid in consequence of the separation of droplets of aniline whilst an evolution of ammonia at the same time becomes percep- tible. The solution now contains a large quantity of oxalic acid. The following equation explains this decomposition C, H,N 0,+2(H0,KO)=2KC,0,+C12H7N+H3N.L-v-_y_J OxaniIamide. Aniline. Dilute sulphuric acid has no effect upon oxanilarnide. Concen-trated acid evolves equal volumes of carbonic acid and carbonic oxide sulphanilic acid and sulphate of ammonia remaining behind CI6H8N20,+3€IS0,=2C02+2CO+ C, H N S 06+H,N SO,. L-v-J L-,"-Oxanilamide. Sulphanilic acid. The. products of the action of hydrochloric acid upon cyani'tine accordingly are Chloride of ammonium Hydrochlorate of aniline Oxanilide Oxamide and Oxarnide-oxanilide. The formation of these substances is intelligible at the first glance; it is due to the propensity which even in its conjugated state found this compound to consider it as the urea of aniline ; subsequent researches how- ever (Chem.SOC. Qu. J. 11. 35) showing that this compound has no basic properties whatever induced me to abandon this lien and to consider the so-called anilo-urea as a double compound of carbamide and carbanilide. Since that period the true anilo- urea possessing all the properties which we are justified in expecting in such a com-pound has been discovered by M. Chancel (Compt. Rend. xxvm. 293) who found that nitrobenzamide discovered by Mr. Field (Chem. SOC. Mem. 111. 404j when subjected to the action of hydrosulphuric acid is converted into anthranilamide or anih-urea. This compound is basic like ordinary urra; it is isomeric with the substance described by me under the name of carbanilamide (carbamide-carbanilide) and produced especially by the action of cyanic acid upon aniline or by the double decomposition of aniline-salts with metallic cpanates.-With regard to carhanilide a substance of the ssnie compo-sition(?) has been of late obtained by MM.Chancel and Laureiit (Instit. 1848 95). This coinpound,$avine which is formed by the action of hydrosulphuric acid upon dini- trobenzophenone is basic j it is ~nlyisomeric not identical Hith carbanilide. VOLATILE ORGANIC BASES. 305 cyanogen retains to assimilate the elements of water ;one equivalent of cyaniline and two equivalents of water contain the elements of one equivalent of ammonia and one equivalent of oxanilide Cyaniline. Oxanilide. and they likewise represent one equivalent of oxamide and one equivalent of aniline Oxamide.Nydrochlorate of Aniline. The formation of oxanilamide requires no farther elucidation this substance being a double compound of the two preceding bodies. The simultaneous production of oxamidc osanilide and the double compound suggested the idea that the latter might be the principal product of the reaction whilst the two former would appear as resulhg from a farther decomposition of the latter. This howtver does not appear to be the case. Often as I repeated this experiment I invariably obtained the three compounds in nearly equal propor- tions nor did I succeed in splitting oxanilamide into its proxi-mate constituents by the action of dilute acids or alkalies or by continuous ebullition.The application of heat likewise which in the case of carbanilarnide had led to such decided results was unsuccessful oxanilamide as mentioned before being volatile without decompasition. The action of dilute sulphuric acid on cyaniline gives rise to per- fectly similar phenomena. The deportment of cyaniline with dilute acids offers an unequivocal proof of the correctness of the formula which I have proposed for this compound. Only in direct combination with aniline is cyanogen capable of yielding oxanilide and oxamide; had it been present in the state of hydrocyanic acid as e. g. in hydrocyanoharmaline for-maailide and forrnainide would have been the products of decompo- sition; lastly if cyaniline had been produced in consequence of a substitution-process we should have expected the formation of cyanic acid and a corresponding compound in the aniline-series or their products of decomposition carbonic acid &c.Action qf Concentrated Sulphuric Acid on Cyani1ine.-Not less characteristic of the constitution of cyaniline is the deportment of this substance with concentrated sulphuric acid. It dissolves in this acid with a violet colour ; the solution when slightly heated evolves equal volumes of carbonic acid and carbonic oxide; on strongly 306 DR. HOFMANN ON THE heating the proportion of carbonic oxide decreases sulphurous acid being disengaged ; after cooling the liquid solidifies into a crys- talline mass of sulphanilic acid sulphate of ammonia being formed at the same time C, H N + 2H SO,+ 2H0 = C, H N S 0 + H,N SO + CO + CO.< J I -Cyadililie. Sulphan’ilicacid. The decomposition illustrated by the preceding equation is in perfect accordance with the assumption of a direct combination of aniline with cyanogen; if hydrocyanic acid had been present car-bonic oxide only could have been evolved while in the case of cyaniline being a substitution-product the action of sulphuric acid should have given rise to the disengagement of carbonic acid only. Action of Bromine upon Cyani1ine.-I have made a few experi- ments on the deportment of cyaniline with bromine the results of which are perfectly intelligible after the preceding remarks respect- ing its behaviour with acids. Cyaniline is violently attacked by bromine; thefirst product of the action appears to be a substitution-body most probably tribromo- cyaniline; under the influence however of the free hydrobromic acid formed in the reaction and assisted by the simultaneous evolution of heat the greater part of the cyanogen-base undergoes the changes which I have detailed in the preceding pages; and the aniline separates in the form of tribromaniline which if alcohol has been present in the reaction crystallizes in beautiful needles as soon as the solution has become cool.The bromine-body was identified by analysis. 0*4000 grm. of substance gave 0.3315 , , carbonic acid and 0.0575 , , water. Experimental Theoretical percentage percentage of in tribromaniline. Carbon . . . 22.60 22.50 Hydrogen .. . 1.59 1*25 Action of Alkalies upon Cyaniline.-This substance is only very slowly and difficultly attacked by potash or soda. Cyaniline may be boiled with either an aqueous or alcoholic solution of potash for hours without undergoing the slightest change. Only when fused with solid potash does decomposition take place aniline together with ammonia being evolved. I naturally expected that the residue should contain oxalate of potash ;but in repeated experiments not a trace of this salt was observed. The action on cyaniline takes VOLATILE ORGANIC BASES. place only at a temperature at which the oxalic acid is converted into carbonic acid with evolution of hydrogen; in an apparatus appropriately arranged the hydrogen evolved in the decomposition of cyaniline by potash may be easily collected.Hence the reaction ensues according to the following equation C y aniline. Aniline. VI. METAMORPHOSES OF DICYANOMELANZLINE. FORMATION OP THE ANILINE-TERM CORRESPONDING TO CYANIC ACID. In describing the bases which are derived from melaniline I have mentioned a compound which is formed by the action of cyanogen- gas upon an alcoholic solution of melaniline and to which I have given the name dicyanomelaniline.* This substance bears in its con-stitution the greatest resemblance to cyaniline ; in its formation melaniline and cyanogen have combined without elimination of hydrogen but while in producing cyaniline the original aniline- atom assimilated but one equivalent of cyanogen the complex struc- ture of melaniline which arises from the combination of two aniline- atoms was exhibited even in its deportment towards cyanogen-gas two equivalents of which are fixed in this reaction the analysis having led to the formula H13 N5 = cy2 '26 H13 N3* In the paper on melaniline I have noticed the remarkable instability of dicyanomelaniline; I have mentioned that the action of reagents and especially of acids on this substance gives rise to a great variety of phenomena of decomposition a more minute investigation of which .however was deferred until the study of the corresponding metamorphoses of cyaniline was completed.The following pages are devoted to a more detailed account of these phenomena. In dicyanomelaniline the basic properties of the melaniline-atom are still perceptible but in a degree very inferior to that observed in the compounds arising from melaailine by substitution.I have vainly endeavoured to produce crystallized combinations of dicyanomelani- line with acids although such bodies are readily formed with the substitution-bases ; in fact the only experimental evidence of the basic nature of this substance is the remarkable facility with which '30 * Chem.SOC. Qu. J. I. 285. 308 DR. HOFMANN ON THE it dissolves in mineral as well as vegetal acids from which solutions it is re-precipitated by the addition of potash or ammonia. The re- precipitation of unaltered dicyanomelaniline however can only be ensured if the solution in acids be saturated immediately with the alkali; after a short time varying with the strength and concentra-tion of the acid employed decomposition sets in and the liquid soon ceases to contain a trace of the cyanogen-base.When speaking of cyaniline I have mentioned that the solutions of salts of this base can exist only for a limited period; the transfor- mation of the corresponding nielaniline-compound goes on with much greater rapidity and whilst in the former case the decompo- sition proceeds only gradually the change in the latter substance is effected almost instantaneously. Dicyanomelaniline dissolves in hydrochloric acid of ordinary con- centration to a clear slightly yellow liquid which if immediately saturated with ammonia yields a precipitate consisting of the cyanogen-compound with all its original properties; if on the con- trary the solution be allowed to stand for a minute or two it sud-denly becomes turbid and deposits a slightly yellowish mass pre- senting an indefinite crystalline appearance.This change takes place almost simultaneously with solution if very concentrated hydrochloric acid be employed or if the dilute solution be gently heated. The mother-liquor from which the new compound has been deposited contains a very considerable proportion of chloride of ammonium. The yellowish substance is but slightly soluble in water by means of which it may be easily purified from hydrochloric acid. It dis- solves somewhat difficultly in boiling alcohol from which it is slowly deposited in a crystalline crust presenting a more individual appear- ance than the original precipitate.The disinclination of this com- pound to assume a very definite crystalline form,-frequently it separates as a resinous mass assuming only very slowly crystalline structure-renders it difficult to obtain it in a state of perfect purity. In the following analyses specimens of different preparations dried at loooC. were employed. Analysis V. refers to a substance obtained by re-crystallizing the compound used in analysis IV. I. 0-3277 grm. of substance gave 0.8100 , , carbonic acid and 0.1195 , , water. 11. 0.3160 , , substance gave 0.7810 , , carbonic acid and 0.1200 , , water. '30 VOLATILE ORQANIC BASES. III. 02805 , , substance gave 0.6969 , , carbonic acid and 0.1041 , , water.IV. 0,4175 , , substance gave 0.4527 , , platinum. V. 0,5065 , , substance gave 0.5657 , , platinum. Percentage-composition I. 11. 111. I v. V. Carbon . . 67.41 67.40 67.76 -Hydrogen . 4.05 4.21 4.12 -Nitrogen . . --15.38 15.84 These numbers may be translated into the expression Hll N3 '4 as is evident from the following comparison of the theoretical with the experimental values Theory. Mean of experiments. P 30 equivs. of' Carbon . . 180 67.92 67.52 11 , , Hydrogen . 11 4.15 4-12 3 , , Nitrogen . 42 15.84 15.40 4 , , Oxygen . . 32 12.09 -265 100.00 This formula readily explains the transformation of dicyanomelaniline under the influence of acids. One equivalent of this substance assi- milates four equivalents of water while two equivalents of ammonia combine with the acid.C, H, N + 4 HO + 2 HCl = C, HI N 0 + 2 H N C1. L J -Dicyanomela-Yellowish compound. niline. A simple method of controlling this equation presented itself in the determination of the amount of nitrogen eliminated in the form of ammonia from a given quantity of dicyanomelaniline when treated with hydrochloric acid. In performing this experiment 2.2529 grm. of dicyanomelaniline gave 3-9415 , , bichloride of platinum and ammonium. Accordingly 100 parts of the cyanogen-body yielded 10.97 parts of nitrogen the amount deduced from the above equation is 10.65. 310 DR. HOFMANN ON THE This determination leaves no doubt respecting the composition of the new substance and this is moreover supported by various pheno- mena of transformation which I shall describe hereafter.The formula derived from analysis although correctly enumerating the elements grouped in the yellow compound leaves us quite in the dark respecting their actual arrangement and consequently of the position which has to be assigned to the substance. A rational interpretation of the analysis was however greatly facilitated by the previous study of the decomposition of cyaniline. The conversion of this substance into oxalates of aniline and ammonia or rather into compounds derived from those salts by elimination of water (oxanilide and oxa-mide) at once gave the clue to the nature of the yellow crystals.They may be considered as binoxalate of melaniline less 4equivs. of water. c, H13 N3 H c 04 + H c 04= c, H, N3 0, C3 HI N3 0 -4HO = CaOH,1 N3 0,. T -Binoxalate of Me-Yellow compound. laniline. Experiment supports this view in an unequivocal manner. On adding ammonia or potash to an alcoholic solution of the compound the liquid readily solidifies into a crystalline mass ; these crystals are pure melaniline ; the mother liquor contains aconsiderable proportion of oxalic acid To avoid any possible mistake I have identified the melaniline produced in this reaction by preparing the platinum-salt and determining the platinum. 0.3482grm of platinum-salt gave 0,0825 , , platinum. Percentage of platinum. Percentage of platinum from melaniline-salt.23.69 23-65 The substance then to which the action of acids upon dicyanome-laniline gives rise belongs to a daily increasing class of bodies which are derived from acid salts of ammonia or of organic bases by elimination of 4 equivs. of water. Succinimide (D’Arcets’ bisnccina- mide) and camphorimide (bisuccinate and bicamphorate of oxide of ammonium4 equivs. of water) were some of the first members of this class with which we became acquainted and in which at a certain period the pre-existence of imidogen (HN) was assumed. In the aniline-series likewise several representatives of this group have been obtained by Laurent and Gerhardt who have proposed the term aniles for these compounds succinanile camphoranile phta- VOLATILE ORGANIC BABE 9.lanile designating in the aniline-series the term8 corresponding to succinimide camphorimide and phtalimide. Hence the term mela-noximide or oxamelanile might be applied to the new compound. It is worthy of remark that the oxalic acid member corresponding to melanoximide is known neither in the ammonia- nor in the aniline-series. Substances produced by dehydration such as oxamide oxamic acid succinimide &c. are reconverted into the compounds from which they are derived not only by the action of alkalies but like- wise by the influence of acids. I was therefore desirous to ascer-tain whether binoxalate of melaniline might be reproduced from melanoximide by treating it with acids. This substance being nearly insoluble in dilute acids sulphuric or hydrochloric their action is but extremely slow ; an alcoholic solution of melanoximide however is rapidly affected by acids especially at the temperature of ebulli- tion.On boiling a solution of this body in strong hydrochloric acid it assumes a deep yellow colour the peculiar somewhat cyanic odour which I had frequent opportunities of noticing during these investigations being evolved in a remarkable manner. After a few minutes the solution again becomes colourless when the presence both of oxalic acid and of melaniline* in the liquid may be traced without difficulty showing that under the influence of acids also the 4 equivs. of water are re-assimilated. Oxalic acid and melani- line are however by no means the only products of this reaction for on cooling the solution deposits long beautiful needles contain- ing neither melaniline nor oxalic acid the examination of which is not yet finished ; the solution contains moreover a perceptible quantity of ammonia.Several of the imidogen-compounds which have been examined such as camphorimide and phtalimide have the properties of weak acids they combine for example with protoxide of silver. The actual nature of these combinations is scarcely understood. Some consider them as compounds of the imides with the oxides others as imides in which hydrogen is replaced by silver; melanoximide is likewise feebly acid it dissolves in very weak solutions of ammonia and potash without decomposition and may be obtained again from these solutions with all its properties on the addition of an acid.Pro-longed contact however with alkalies especially when concentrated * The reproduction of melaniline from melanoximide by the action of acids was likewise proved by the preparation and analysis of a platinum-salt ; 0.3177 grm. of salt gave 0.1 206 grm. = 23.29 per cent of platinum. The theoretical percentage of platinum in the melanilhe-salt is 23.65. DR. HOFMANN ON THE as stated before gives rise to assimilation of water binoxalate of melaniline being formed. ,4 solution of melanoximide in dilute alcohol especially when containing a few drops of ammonia yields a slightly yellowish amorphous precipitate with nitrate of silver. The analysis of this silver-compound has not led to any precise result by igniting three different speciniens of the silver-salt a per- centage greatly varying (25.41-28.57 and 30.5 of silver) was obtained.A compound of melanoximide with 1 equiv. of protoxide of silver would contain 28.4per cent of silver. To the acceptation however of such a compound fkrther experimental evidence would be requisite. It remained now only to try whether melanoximide the nature of which appeared to be sufficiently established by the preceding expe- riments might not be actually obtained by the action of heat either alone or assisted by agents of dehydration upon binoxalate of mela-niline a salt which I have mentioned in the description of mclani-line.* Here a difficulty presented itself at once in the facility with which melaniline is decomposed when heated it appeared by no means easy to regulate the temperature in such a manner as to confine the reaction to an elimination of water without affecting the residuary compound.Nor have T-it may at once be statcd-been able to effect the desired conversion ; the experiment however although unsuccessful as to its intended object .has led to a result as remarkable as any that has been elicited in the course of these researches.-On heating binoxalate of melaniline the salt fused and entered soon into a sort of ebullition torrents of carbonic oxide and carbonic acid being evolved; towards the end of the operation a splendid crystalline subliniate appeared in the neck of the retort which was found to be carbanilide while a transparent viscid mass solidifying on cooling into a resin-like substance remained behind.The gas which is evolved in this process possessed in a very powerful degree the peculiar odour to which in this as well as in former communications I have repeatedly alluded. Never indeed had I met before with a reaction which appeared to give rise to so large a quantity of this peculiar compound and I began to hope that I should at last succeed in securing this enigmatical body which I had vainly'chased on so many occasions. My endeavours however to condense this substance from the mixture of carbonic oxide and carbonic acid in which it was diffused were fruitless; and I did not succeed until I began to study the action of heat on melanoximide itself instead of on binoxalate of melaniline.* Chem. SOC. Qu. J. I. 285. VOLATILE ORGANIC BASES. 313 Action of Heat on Melanoxirnide. Anilocyanic Acid,(Carbade-)-The dry distillation of melanoximide presents phenomena similar to those observed on heating binoxalate of melaniline. The mass fuses and evolves a large quantity of gas in which however the presence of carbonic oxide predominates to such an extent that in certain stages of the process scarcely any carbonic acid is detected. During the disengagement of the gas a slightly yellow liquid distils over of a most powerful odour recalling at once the odour of aniline of cyan- ogen and hyclrocyanic acid,. provoking lachrymation in a most fearful manner and exciting too in the throat the suffocating sensation produced by the latter.Small quantities of this liquid which is by no means very volatile evaporate in the gas which is evolved during the process and impart to it this penetrating odour in such a degree that it is necessary to collect the gas in order to escape its irritating action on the nose and eyes. Towards the end of the dis- tillation on raising the temperature very considerably together with the liquid a solid body is evolved which is deposited in radiated crystals on the neck of the retort and carried over iuto the receiver while a slightly coloured transparent resin-like compound remains in the retort very similar to the residue obtained in the dry distillation of melaniline. The quantity of crude liquid obtained in this process amounts to about ten per cent of the melanoximide employed; it is necessary to avoid as carefully as possible the pre- sence of moisture either in the substance to be distilled or in the retort or receiver in order not to reduce still farther in quantity the product of the operation the liquid being readily decomposed by water.This deportment explains why in the distillation of binoxalate of melaniline (distinguished from melanoximide only by containing 4 equivs. of water more) only traces of this liquid are obtained. It is evident that the elimination of water and the formation of the com- pound take place simultaneously decomposing each other at the very moment of their liberation." In purifying the yellow liquid the nhite crystalline matter with which it is always contaminated has to be separated.This cannot be effected by distillation the boiling-points of the two bodies being SO very close to each other that the distillate invariably contains again a portion of the crystals. The separation succeeds best by cooling the liquid in order to cause as complete a deposition of the * I have endeavoured to avoid the liberation of the water by mixing the binoxalate with anhydrous phosphoric acid. The result however was not satisfactory nearly the whole mas8 being charred. VOL. 11.-NO. VIII. Y DR. HOFMANN ON THE crystalline matter as possible and filtering through fine bibulous paper. A very limited quantity of the compound being at my dis- posal I contrived to filter it as perfectly as possible by atmospheric pressure the funnel being fixed by means of a perforated cork into a little flask from which part of the air had been expelled by heat.On cooling the liquid was forced through the paper while the crys- talline compound remained on the filter. The presence of moisture having been carefully excluded in all the operations it was now sufficient to rectify the liquid in order to obtain it in a state fit for analysis; on distillation in a glass tube the liquid entered into regular ebullition at 178"C. ; during the latter part of the distillation the thermometer rose very gradually to 180° C. Thus obtained the substance formed a colourless very mobile liquid heavier than water strongly refracting light and possessing the powerful odour in undi- minished intensity.For the following analyses specimens of different preparations were employed. Carbon-determination I. was made with a product of a first operation prepared at a period at which I was less acquainted with the habits of the substance in question ; carbon-determination 11. and nitrogen-determination 111. refer to a speci-men prepared at a later period and on a larger scale. When burnt with protoxide of copper I. 0.2041 grm. of liquid gave 0.5226 , , carbonic acid and 0*0810 , , water. 11. 0-2610 , , liquid gave 0.6720 , , carbonic acid and 0-1020 , , water. The nitrogen was estimated by passing the vapour of the liquid over a long layer of soda-lime and proceeding with the resulting mixture of ammonium- and aniline-platinum-salts as indicated in the analysis of cyaniline.* 111.0.4557 grm. of liquid gave 0.3830 , , platinum. Percen tage-composition I. 11. 111. Carbon . . 69.83 70.21 -Hydrogen . . 4.40 4.341 -Nitrogen . . -11.92 * Chem. SOC. Qu.J. I. 159. VOLATILE ORGANIC BASES. These numbers especially if we rely more particularly on the results obtained in the analysis of the second specimen may be expressed by the formula which requires the following values 14 equivs. of Carbon. . . 84 70.58 5 , , Hydrogen . . 5 4.20 1 , , Nitrogen . . 14 11-76 2 , , Oxygen . . 16 13.46 1equiv. of the odorous Compound . 119 100.00 The preceding formula is corroborated by a series of reactions of remarkable precision presenting perhaps when taken as a whole a higher order of experimental evidence than can be obtained from any elemeutary analysis however accurate it might be.Before entering into a detailed account of these reactions the position of the new compound may be directly fixed by the inquiry whether a corresponding term exists in the ammonia-series. By subtracting from the above formula the elementary difference dis- tinguishing aniline from ammonia namely c, H4 we arrive at once at a well-known formula The formula C2 H N 0 expresses the composition of hydrated cyanic acid and accordingly the new compound would represent in the aniline-series the term cyanic acid; or in other words the odorous liquid would stand in the same relation to aniline as hydrated cyanic acid stands to ammonia.The reactions of cyanic acid being very clearly defined there was no difficulty in tracing by experiment the analogy of the two compounds. It may here at once be stated that this analogy has been found to be perfect in almost every direction so that for the sake of shortness I will designate the liquid in question by thenarne ado-cyanic acid although from reasons which will soon be evident I have not been able to produce compounds analogous to the cyanates. The action of acids and bases upon anilo-cyanic acid appeared to offer the first standard of comparison. Both classes of agents convert cyanic acid into ammonia and carbonic acid 2 equivs. of water being assimilated. Exactly the same effect is exerted on ado-cyanic acid.This compound is readily attacked by potash Y2 31 6 DR. HOFMANN ON TIIE or hydrochloric acid aniline or carbonic acid being evolved while carbonate of potash or hydrochlorate of aniline remains behind C H N 0 + 2 HO = H N + ZCO,. C, H N 0 + 2 HO = C, H N + Z CO,. If concentrated sulphuric acid be employed instead of hydrochloric we obtain in the place of hydrochlorate of aniline sulphanilic acid as might have been expected.-Cyanic acid is capable of fixing water even if acids and alkalies be absent in this case however the meta- morphosis extends over two equivalents. The ammonia eliminated in the decomposition of the first combines with a second equivalent of cyanic acid not yet affected urea or bicarbamide being produced with evolution of carbonic acid.In a similar manner anilo-cyanic acid when treated with water gives off carbonic acid very slowly at common temperatures more rapidly however on the application of heat while the oil is converted into a crystalline mass. The crystals thus formed are insoluble in water but dissolve in alcohol; they have all the properties of carbanilide.* The following combustion would have been scarcely necessary. 0.1743 grm. of crystals gave 0.4675 , , carbonic acid and 0.9040 , , water. Percentage Experimental. Theoretical in carbanilide. Carbon . . . 73.15 73-58 Hydrogen . . 5.76 5-66 If we recollect that urea may be viewed as bicarbamide the analogy of the reactions of both cyanic acids with water becomes at once perceptible the one yielding 2 equivs.of carbamide the other 2 equivs. of carbanilide as exhibited by the following equations 2 C H N 0 + 2 HO = C H4 N 0,+ 2 CO C H4 N 0 = 2 (H2 N CO) 2 C14 H N 0,+ 2 HO = C, H, N 0,+ 2 CO C, HI N 02 = 2 (C H6 N CO). Not less symmetrical are the changes which the two analogues undergo when treated either with aniline or with ammonia. Cyanic acid when treated with aniline yields carbamide-carbanilide ; ado-cyanic acid on the other hand yields carbanilide. C H N 0,+ Cl H N = C,4 H N 0 = H N CO + C, H N CO C14 H N 0:+ C, H N = Cz6 HI N 0,= C, H,j N CO + Cis Rj N CO. * Chem. SOC. Qu. J. 11. 36. VOLATILE ORGANIC BASES. 31 7 In the Bame manner ado-cyanic acid when heated with ammonia is converted into carbamide-carbanilide whilst the action of ammonia on cyanic acid itself gives rise to the production of urea or bicar-bamide.C H N 0,+ H N = C H N 0,= H N C 0 + H N CO C, H N 0,-t H N = C, H N 0,= H N C 0 + C, H N CO. These several reactions are effected instantaneously on adding either ammonia or aniline to the oil which at once solidifies a considerable amount of heat being disengaged. It is not unlikely that a similar effect may be produced by all ammonides (a term which may be used for the class of bases represented by ammonia) ;a small quantity of cumidine having remained in the collection of the College from Mr. Nicholson's investigation I placed the two substances in contact ; the mixture eolidified at once to a crystalline mass j the product not being in sufficient quantity for combustion was not examined farther ; there cannot however remain the slightest doubt that it is a double compound of carbanilide and carbocumidide analogous to carbarnide- carbanilide and oxamide-oxanilide whose formation may be repre- sented by the following equation Toluidine and even leucoline which is remarkable for its disinclina- tion to form crystalline derivatives exhibit a similar deportment.Aido-cyanic acid when acting upon the various alcohols on pyroxylic spirit wine-alcohol and fusel-oil and even on hydrated oxide of phenyl (carbolic acid) gives results not less marked; and here again an analogy with ordinary cyanic acid may be traced to a very great extent.Anilo-cyanic acid dissolves in the alcohols with considerable evolution of heat clear liquids being formed which after some minutes deposit magnificent crystals. These crystals are readily fusible at the boiling temperature of water they are insoluble in this liquid but soluble in all proportions in alcohol and ether. The bodies to which these reactions give rise are generally mixtures; and it is but with difficulty that the individual components are separated. I cannot at this moment offer to the Society definite numbers unequivocally fixing the composition of these bodies ;how-ever from approximative combustions,* performed with substances * Not knowing whether and when I shall be allowed to return to this investigation I here subjoin the numbers obtained in the combustion both of the methyl- and ethyl- DR HOFMANN ON THE not absolutely pure and employed in quantities insufficient to secure an accurate determination of the hydrogen I have already formed a decided opinion respecting the nature of the substances produced in these reactions.From the researches of Liebig and Wohler on the action of cyanic acid upon the alcohols we know that the latter class of bodies is capable of directly fixing either one or two equivalents of the former. Two classes of compounds are thus produced the urethanes or car-bamic ethers (obtainable also in a variety of other remarkable reactions) and the substances termed allophanic ethers. Alcohol. Cyanic acid. Uret'hane Carbamate of ethyl. C H 0 + 2 H C N 0,= C H N20 -\+ \+ Alcohol.Cyanic acid. Allophanate of ethyl. compounds which were prepared however on so small a scale as to preclude the possi- bility of an efficient purification. ANALYSIS OF THE METHYL-COMPOUND. 0.1970 grm. of substance gave 04580 , , carbonic acid and 0*1310 , , water leading to the percentage Carbon . . . . 63.40 Hydrogen . . . 7-39 The formula c H9 N 0, requires Carbon . . * . 63.57 Hydrogen . . . 5.96 ANALYSIS OF THE ETHYL-COMPOUND. 0.1035 grm. of substance gave 0.2533 , , carbonic acid and 0.0620 , , water leading to the percentage Carbon . . . . 66.14 Hydrogen . . 6.65 The formula c,,4,N 04 requires Carbon . . . . 65.45 Hydrogen . . . 6.66 The results obtained in the preceding experiments incorrect as they are leave but little doubt in my mind respecting the existence of the two compounds in question ; stlll the experiments will have to be repeated on a larger scale in order to fin their existence by more characteristic numbers.VOLATILE ORGANIC BASES. Now anilo-cyanic acid appears to exhibit a similar deportment. I have convinced myself by analysis that the ordinary alcohols absorb 1 equivalent of anilo-cyanic acid giving rise to the production of the following series of compounds. Methyl-compound . . C16H N 0,= C H 0 + C14 H N 0 Ethyl-compound . . H,,N 0 = c4 H 0,+ c, H N 0 Amyl-compound . . C, H,7 N O4 = C, H, 0 + C, H N 0 I cannot speak positively as to the existence of compounds corres- ponding to the second class of derivatives produced by the action of ordinary cyanic acid upon the alcohols nor will I here venture an opinion respecting the substance formed by the action of anilo-cyanic acid and hydrated oxide of phenyl.If we are justified in considering the urethanes as compound ethers in which a peculiar acid carbamic acid pre-exists it would follow that the preceding series would have to be regarded as the ethers of carbanilic or anthranilic acid with whose composition they coincide. C6 H N 0,= C H, C H N 0, -+ - Urethane. Carbarnate of ethyl. c18 HI N 04 = c4 H, c14 H O4 L+ -Anilo-uiethane. Carbanilate or anthranilate of ethyl. I am unable to say whether these substances actually contain anthranilic acid or whether they are only isomeric with the true anthranilic ethers.Nothing would have given me more pleasure than to pursue the investigation of these compounds farther ; they present a peculiar interest because we may expect that under the influence of powerful removers of carbonic acid the ethers of car-banilic acid similarly to the cyanic ethers will yield a series of new bases derived from aniline by the substitution of methyl ethyl or amyl for 1 equiv. of hydrogen. But unable to indulge in a more detailed study of these beautiful reactions in consequence of want of material I must postpone their completion until a simpler method may have been discovered of obtaining in a shorter time a larger quantity of anilo-cyanic acid. The preparation of aniline from indigo or benzole its purification the conversion into melaniline the subsequent treatment of this base with cyanogen-gas and the transformation of the resulting dicyanomelaniline into melanoximide which when distilled yields but a small percentage of anilo-cyanic acid-this long and compli- DR.HOFMANN ON THE cated series of metamorphoses have caused no small expenditure of time and labour nor could I have found sufficient leisure to follow out the manifold ramifications of the aniline-family in its numerous and often so intricately related derivatives whose history I have endeavoured to trace before the Society had it not been for the valuable assistance and co-operation of Messrs. Nicholson and Abel Assistants in the College of Chemistry.I cannot but make mention publicly of the unremitting zeal and the remarkable experimental skill with which during several years these gentlemen have assisted me in the prosecution of the researches on the volatile organic bases. Having in the preceding pages endeavoured to fix the composition and the nature of anilo-cyanic acid we will now return once more to the circumstances under which this substance is formed in order to trace as far as possible the connexion in which this compound stands with melanoximide the dry distillation of which gives rise to it. The decomposition by heat of so complex an atom as melan-oximide must necessarily be a process of considerable intricacy. By the great variety of products which are simultaneously formed carbonic oxide carbonic acid anilo-cyanic acid the crystalline sublimate and the resinous residue we are led to believe that several metamorphoses are accomplished side by side in this reaction; nor do I pretend to be in possession of a sufficient number of facts for a satisfactory explanation of all the phenomena.I offer the following remarks only as an expression of the idea which I have myself formed respecting this decomposition leaving it to others to suggest any other interpretation of the facts which may seem to them more probable. In order to understand the effect of heat upon melanoximide it will be necessary to premise a few details respecting the action exerted by heat upon melaniline itself. Action of Heat upon Melaniline.Melaniline may be exposed to the heat of boiling water without un- dergoing any change betwcen 120°C. and 130' C. the substance enters into a state of fusion and solidifies on cooling with crystalline struc- ture On raising the temperature however to 150° and then after- wards to 170° C. decomposition ensues. At the latter temperature perfectly colourless drops of pure aniline distil over. In the com- mencement of this distillation no trace of ammonia is perceptible; this gas is formed however after the lapse of some time even if the temperature be accurately kept between 150° and 170° C. and is disen-gaged abundantly on raising the temperature. It is almost impos- sible to regulate the heat so as to evolve aniline only without causing VOLATILE ORQANIC BASES.at the same time the elimination of ammonia. These observations show that it must be extremely difficult to obtain the residue of this operation of constant composition. This residue is a transparent slightly yellowish resinous brittle mass insoluble in water dissolving only with difficulty in alcohol a turbid liquid being produced which filters very slowly. It is soluble in concentrated sulphuric acid and reprecipitated on the addition of water in white flakes in which the substance appears to be in an altered state. The residue obtained by heating mrlaniline was repeatedly analysed. I adduce the following combustions made with products obtained in different operations. I. 0-1927grm. of substance gave 0°5108 , , carbonic acid and 0*0980 , , water.11. 0.3730 , , substance gave 1.0043 , , carbonic acid and 0.1710 , , water. 111. 0.2970 , , substance gave 0.8017 , , carbonic acid and 0.1360 , , water. IV. 0.3185 , , substance gave 0.8670 , , carbonic acid and 0.1525 , , water. Percentage I. 11. 111. IV. Carbon . . . 72.29 73*43 73-62 74.24 Hydrogen . . 5.65 5-09 5.08 5.32 Among these analyses I am inclined to place most confidence in experiment I for which the substance had been prepared with the greatest care very little ammonia having been evolved. To ensure the absence of adhering aniline the compound had been dissolved in alcohol mixed with a few drops of hydrochloric acid and reprecipi- tated by water washed with dilute ammonia and dried.The remainder of the combustions were made with specimens ob- tained by the action of heat only. The results from analysis I the difference being assumed to be nitrogen may be translated into the formula c, H, N, which requires the following values 54 equivs. of Carbon . . . . 324 72.49 25 , of Hydrogen. . . . 25 5.59 7 , of Nitrogen . . . . 98 21.92 -1 equiv. of Melaniline-residue 447 100~00 DR. HOFMANN OX THE The simplest interpretation of this formula consists in regarding it as a compound of the aniline-mellon with 3 equivs. of aniline. Mellon . . . . C N Aniline-mellon . . C N (C12 H4) = C, H N C,* H25 N7 = Cis H N4 + 3 C1 H N* If this formula actually represents the composition of the body in question its formation would be the result of the separation of 2 aniline-atoms from 3 equivs.of melaniline. 3 C26 K3 N3 = 2 C12 H N = C6.4 H2 N7 I have endeavoured to verify the formula in question by deter- mining the percentage-loss siffered by melanil& on expbsure to heat. The following experiment will prove that the action of heat gives rise to a series of changes which it is very difficult to confine to separate stages the various periods of the process beingbut very indistinctly defined. When exposed for several hours to 170° C. in an air-bath I. 0.2993 grm. lost . . 0-0910grm. = 30.40 per cent after another hour . 0.0937 , = 31.30 ,, IT. 0.2980grm. lost . . 0.0867 , = 29.09 , after a second hour . 0.0970 , = 32.55 , 111. 0.6517 grm.lost. . 0.2005 , = 30.76 , IV. 2.1840 , lost . . 0.682 , = 31-22 , On continuing the experiment ammonia was abundantly evolved and the loss rose gradually to 35 and even to 37 per cent. From these experiments it appears that rnelaniline when exposed to a tem-perature of 170° C. loses about 30 per cent of aniline and that after this the decomposition enters into a new phase ammonia being first slowly and by degrees more rapidly evolved. The theoretical loss required by the assumption that 3 equivalents of melaniline yield 2 equivalents of aniline is 29.38; however the impossibility of avoiding the evolution of ammonia altogether would explain to a certain extent both the almost invariable excess exhibited by the latter experiments the excess of carbon and the deficiency of hydrogen in several of the elementary analyses.Accordingly without extending our considerations to the later products of the action of heat on rnelaniline we are justified in VOLATILE ORQANIC BASES. 323 assuming that at a certain stage of the proceas the residue in the retort consists chiefly of a product which may be regarded as anilo-mellon + 3 equivs. of aniline. This mode of viewing it is moreover supported by two analogies. The substance discovered by Liebig in the distillation of sulpho- cyanide of ammonium and described under the name of melam may be considered as a compound of 2 equivs. of mellon and 3equivs. of ammonia. H N,1= 2 C N + 3 H N and it is known that this body is decomposed accordingly by heat.Again in subjecting chlorocyanilide to the action of heat M. Laurent obtained a substance possessing properties very similar to those of the melaniline-residue which from the mode of its formation must almost certainly be i. e. anilo-mellon + 1equiv. of aniline. Action of Heat upon Melanoximide. The preceding account of the action of heat upon melaniline incomplete as it is and insufficiently supported by experiment though it may appear will nevertheless assist us in understanding the changes which melanoximide undergoes in the formation of anilo-cyanic acid. Melanoximide ado-cyanic acid and hydrated cyanic acid are substances of the same order. They all may be considered as having been derived from acid salts by the elimination of 4equiva.of water. Melanoximide is binoxalate of melaniline -4equivs. of water ; anilo-cyanic acid bicarbonate of aniline -4 equivs. of water whence the name anilo-carbimid or in Gerhardt and Laurent’s nomenclature the term carbanile might be used for this compound; cyanic acid or carbimide lastly is bicarbonate of oxide of ammonium -4equivs. of water as illustrated by the following table into which I intro-duce as second term melano-carbimide a substance which has still to be discovered and which would be derived from bicarbonate of melaniline in the same manner as anilo-cyanic acid and common cyanic acid may be supposed to originate from the bicarbonates of the respective bases. DR. HOFMANN ON THE Melanoximide . . C, Hll N O4+ 4 HO = C, H, N, 2 H C 0 Melano-carbimide .C, H, N 0 +4 HO=CQ6H, N, 2 H C O,(?) Ado-cyanic acid . C14 H N 0,+4 HO=C12 H N 2 H C 0 Carbimide . . *} C H N 02+4!Ho= H N 2HC 0, Cyanic acid . Now if we recollect that the distillation of melanoximide is attended with a very considerable evolution of carbonic oxide it does not appear improbable that the first result of the action of heat is the actual formation of melano-carbimide for C3 H, N O4 -2 CO = C2 H, N 0 -Melanoximide. Melano -carbimide. Melano-carbimide then would yield anilo-carbimide or anilo-cyanic acid in the same manner as melaniline on exposure to heat evolves aniline. Supposing the decomposition of the two substances to be parallel the action of heat upon the former would be repre- sented by the following formulx! '28 '2N3Hll = '84 H33 N9 '6 H5 '2 = '28 HIO N2 '4 '14 The residue left in the retort after the distillation of melanoxi-mide which in its physical characters strikingly resembles the analogous melaniline-residue would also by its composition become a substance of similar order it might be considered as a compound of anilo-mellon with 2 equivs.of aniline and 1 equiv. of ado-cyanic acid. Melaniline-residue . . . . C, H N =Cis H N + 2 C, H N + C, H N Melanoximide-residue . . . C5 H N O,=C H N,+ 2 C, H N + C, H N 0 I have analysed the residue and the numbers obtained partially appear to confirm this view as far as confirmation can be expected by the combustion of a compound produced in so complicated a reaction which is neither crystalline nor volatile.I. 0-3080grm. of the residue gave 0*8050 , , carbonic acid and 0.1140 , , water. 11. 0-2070 , , the residue gave 0.2885 , , platinum. VOLATILE ORGANIC BASES. Percentage-composition I. 11. Carbon . . . . 71.28 Hydrogen . . . 4.14 -Nitrogen . . . -19.77 The above formula requires the following values 56 equivs. of Carbon . . . . 336 71-04! 23 , , Hydrogen . . . 23 4.86 7 , , Nitrogen . . . . 98 20.72 2 , , Oxygen . . . . 16 3.38 -473 loomoo Accordingly the conversion of melanoximide into ado-cyanic acid would be represented by the following equation Melanoximide. Anilo-cyanic acid. Residue. The compounds enumerated in the second part of this equation are however by no means the only products of the reaction.I have repeatedly mentioned that together with carbonic oxide a certain quantity of carbonic acid is evolved. This gas appears to be the result of a secondary decomposition for repeatedly though I have determined the proportion of this acid relatively to the carbonic oxide I have not been able to obtain concordant results either in different experiments or in the various stages of the same operation j invariably the amount of carbonic acid is very small. A farther secondary product is the crystalline sublimate which appears espe- cially in the last part of the distillation when the temperature is highest; this compound which if the heat be continued for some time is deposited as a coating of radiated texture all over the neck of the retort,-some crystals being even carried into the receiver,-was collected pressed between bibulous paper and crystallized from boiling alcohol when it was obtained in beautiful long needles.Analysis proved this substance to be perfectly pure carbanilide. 0.2880grm. of substance gave 0.7774 , , carbonic acid and 0.1480 , , water numbers leading to the following percentage of carbon and hydrogen which I place in juxtaposition with the theoretical values. Experiment. C, H N 0. Carbon . 73-61 73-58 Hydrogen . . 5.71 5-66 DR. HOFMANN ON THE The reactions and properties of the substance are likewise identical with those of curbanilide obtained in other processes. In what manner is carbanilide formed in the dry distillation of melanoximide? I think that we may account for the formation of this compound in two different ways.Suppose that at the high temperature at which the process is accomplished a certain quantity of hydrogen and oxygen is eliminated from the residue in the form of water the water coming into contact with the vapour of the anilo-cyanic acid is decomposed carbanilide being deposited in crystals while carbonic acid is evolved 2C1,H N 02+2HO=2C,3 H N 0+2CO,. We have seen above that this formula is strictly verified by direct experiment and it may be mentioned here that the impossibility of obtaining more than traces of anilocyanic acid in the distillation of the binoxalate of melaniline is accounted for by the evolution of the 4 equivs.of water by which this salt exceeds the composition of melanoximide and which are sufficient to convert the whole of the anilocyanic acid into carbanilide and carbonic acid and hence the large quantity of carbonic acid evolved and the considerable amount of carbanilide sublimed in the distillation of binoxalate of melani-line. This reaction then would explain both the presence of carbonic acid and carbanilide among the products of distillation of melan-oximide. However though it is very probable that a process like that just mentioned co-operates in the formation of carbanilide I nevertheless believe that by far the larger quantity of the amount produced in the distillation of melanoximide is due to another reaction.In glancing once more at the expression for the residue of melanoximide we perceive that in the theoretical formula which suggested itself namely there occur together with that of anilo-mellon the formuh of aniline and anilocyanic acid. Now when enumerating the reactions of the latter compound I have mentioned that on adding it to aniline the mixture solidifies at once into a crystalline mass of carbanilide. C,,H,NO + C, H7N = 2C,,H6N0. LA -*+ Anilocyinic acid. Aniiine. Carbanilide. VOLATILE ORGANIC BABES. It is very probable that the larger quantity of the carbanilide accompanying the anilocyanic acid is due to a similar reaction 1 equivalent of aniline and 1 equivalent of anilocyanic acid separating from the residue which would thus be converted into the anilo- mellon containing 1 equiv.of aniline which I mentioned above as having been obtained by 31. Laurent in the action of heat upon chlorocyanilide. Melanoximide-residue . . } H N&+f2Cl H7 + cl,H O?,= c56 H23N70% 2 equivs. of cl H7 N+C14 H6 N02=C26 H12N202 Carbanilide } Laurent’s Ani- } Cl H N, + Cl H7 N = c30 H, N,* lo-mellon This view is partly supported by experiment. A portion of the melanoximide-reeidue from which by continued strong heat every trace both of anilo-cyanic acid and of carbanilide had been expelled was subjected to analysis when the following results were obtained 0.3708 grm. of residue gave 0.9146 , , carbonic acid and 0.1515 , , water. Percentage Carbon .. . . . 67-27 Hydrogen . . . . 41-54 The formula requires the following values 30 equivs. of Carbon . . . . . 108 68.97 11 , , Hydrogen . . . . 11 4.21 5 , , Nitrogen . . . . 70 26.82 1 , , Ado-mellon and Aniline 261 100.00 It is possible that the loss of carbon may have been occasioned by incomplete combustion these substances burning with very great difficulty; be this however as it may I do not attach great importance to the analysis of these amorphous bodies produced at high temperatures and offering no guarantee of purity and indi- viduality and am inclined to consider the preceding scheme of the action of heat on melaniline and melanoximide more as a probable theory than as il strict interpretation of unequivocal facts. DR.HOPMANN ON THE Having enumerated in the preceding pages the various facts concerning anilo-cyanic acid which have been elicited during my researches it remains now only briefly to point out some interesting relations in which this compound stands to other groups of bodies. In the beginning of this year M. Wurtz published some remarkable experiments upon the metamorphoses exhibited by the compounds of the alcohol-radicals with cyanic acid. In these several substances exactly as in anilo-cyanic acid the original habits of cyanic acid in its behaviour with other bodies are retained in almost every direction. We have obtained in this manner a series of compounds of which cyanic acid is as it were the type C H N 0 C2 H N 02 (C2 H2) c H N 02 (C.4 H4) L---J ---7f--+ Cyanic acid.Methylo-cyanic acid or Ethylo-cyanic acid or Cyanate of Methyl. Cyanate of Ethyl. c2 H N 02 (ClO HlO) c2 HNO (C12 HB) LY--Amylo-cyanic acid or Anilo-cyanic acid or Cyanate of Amyl. Cyanate of Phenyl. All these substances are capable of fixing directly 1 equiv. of ammonia a series of compounds being produced analogous in com- position to urea c2 H N2 02 c2 H4N2 02 (C2H2) c2 H4 N2 02 (C4 4) ++ L-v-L --Urea. Methylo-urea. Ethylo urea. y2 H4 N2 99 (Go HlO) c2 H4 N2 02 PI2 H4)* Lv-Amylo-urea. Anilo-urea Carbamide-carbanilide. When in contact with water 2 equivs of the various cyanic acids assimilate 2 equivs. of water 2 equivs. of carbonic acid being evolved. In this case compounds are formed which are analogous to carba-mide urea appearing here as bicarbamide H2 E,CO; N H2 CO H2 N CO (C H,) H2 N,CO (C H,) L-”.-d L J -Urea bicarbamide methy lo-cabamide.Ethylo-carharnide H2 N co (CI* HlO) H2 N co (GI2 H4)* Amylo-carbamide. Anilo-Carbamide Carbanilide Phenylo-carbamide. Lastly when treated with the alkalies 2equivs. of water are fixed ; a series of conjugated ammonias being formed while carbonic acid is eliminated VOLATILE ORGANIC BASES. 329 H,N; H3 N (C H2); H3 N ((34H4) ;H3 N Go HlO) ; H3N (C184)- L-LL-Lpv-J L-+ Ammonia. Methyl-ammonia Ethyl-ammonia Amyl-ammonia Phenyl-ammonia Methylamine. Ethylamine. Aniylamjne.* Phenylamine Aniline. The preceding synopsis shows the analogy of these various com-pounds in a sufficiently perspicuous light ; it requires no farther comment.I will observe only that these analogies begin to exhibit the alcoholic nature of phenole in a very forcible manner. In fact in anilo-cyanic acid we add a new member to the phenole- group in which already some of the most important terms of the common alcohol-aeries are represented. Alcohol . . . . C,H,O €I0 Phenole. . . . . C,,H,O,I-IO Sulphethylate of ba-Sulphophenate of ba-rium . . . . C,H,SO,,BaSO rium. . . . . C,,H,SO,,BaSO Chloride of ethyl . C €I CI Chloride of phenyl . C, H C1 (?) Metacetonitrile . } Cyanide of phenyl 1 Cyanide of ethyl Benzonitrile . . C12H5Cy=C14H5N . . C6HGO4 '4 J H5 Cy=C6H5 Metacetic acid Benzoic acid . . . C,,H,04 Metacetic ether .. C,H C H 0 Benzoate of phenyl . C, H C, I-I 0 Cyanate of ethyl . o2 Cyanate of phenyl } Ethplo-cyanic acid} 5' Anilo-cyanic acid Ethylo-carbamide c5H6 Phenylo-carb amide Carbethylamide Carbanilide O2 'I2 '2 H5 } Ethylo-urea . . . } . . HGN Cl4HsN,O2 C H8N20 Anilo-urea . . . . Ethylammonia Phenylamine . . H7 Ethylamine . }C4H7N Aniline . . . . } '12 The preparation of ado-cyanic acid being as mentioned above attended with considerable difficulty the new aspect under which this compound appears when considered as cyanate of phenyl could not but induce me to try whether it might not be formed in the same manner as the alcohol-cyanates. The latter compounds and the corresponding aniline-term although as we have seen perfect analogues have been obtained by very different processes.The alcohol-cyanates are formed like so many other compound ethers simply by distilling a mixture of a sulphethylate and a cyanate; indeed these substances form the starting point of the alcohol-bases while in the case of cyanate of phenyl or anilo-cyanic acid this body has to be constructed as it were by very complicated reactions from the phenole-base itself. Cyanate of phenyl however is not produced under those circum- stances which give rise to the formation of cyanate of methyl ethyl * M. Wurtz assigns to this compound the term valeramine but I think amylamine is a more appropriate appellation. VOL. IT.-ETO. VIII. 2 DR. HOFMANN ON THE or amyl. I have in vain distilled a mixture of cyanate of potash with sulpkiophenate of baryta ; the smallest trace of anilo-cyanic acid would have been at once detected by the nose; it is not formed in this reaction.* Incidentally to this experiment I have distilled sulphophenate of baryta with cyanide of potassium ; this reaction might have given rise to the formation of cyanide of phenyl or benzonitrile a transformation which appeared of some interest inasmuch as it would have enabled us to reach from phenole upwards to benzoic acid in the same manner as we now step from one alcohol- family through the cyanide or nitrile into the acid term of the family following next on the scale of organic compounds; however in distilling sulphophenate of baryta with sulphethylate of potash no benzonitrile is obtained.The impossibility of obtaining cyanate and cyanide of phenyl in the same manner as the corresponding terms in the methyl- ethyl- and amyl-series sufficiently shows that the properties of the phenyl-alcohol differ in many respects from those of the alcohols C Il(n +2 02,)(nrepresenting the numbers 2 4,6 &c.) ;we might in fact adduce a variety of other dissimilarities; but we have to recollect that phenole is no homologue but only an analogue of common alcohol the number of carbon-equivalents considerably exceeding that of the hydrogen-atoms while the above alcohols as indicated by the general formula invariably contain an excess of hydrogen. Notwithstanding these discrepancies it may not be useless to bear in mind the alcoholoid habit of the phenole-family were it only that its various derivations might assist us in increasing the sources so scanty at present of alcohol formation.One of the most definite processes effecting the production of phenole is the exposure of salicylic acid to heat or the action of alkaline earths upon it. Now we know from M. Strecker’s experiments a continuation of which is impatiently expected by chemists that the deamidation of glycycin (glycycol) sarcosin and leucin gives rise to a series of acids containing 6 equivalents of oxygen and standing to the ordinary * I may mention here some other unsuccessful experiments which I have tried in order to obtain anilo-cyanic acid. This compound contains the elements of anthranilic acid or salicylamide -2 equivs.of water C, 11 N 0,-2 HO = C, H N 0, + cd Ant hranilic acid . Anilo-cyanic acid. S alicylamide. I have distilled anthranilic acid and salicylamide with anhydrous phosphoric acid but no ado-cyanic acid is produced the action going evidently too far. In the case of anthranilic acid nearly the v hole substance is charred. - Compounds produced from Neutral Salts by elimination of 2 equivs. of Water. Compounds produced from Neutral Salts by elimination of 4 equivs. of Water. Compounds produced from Acid Salts by elimination of 2 equivs. of Water. Compounds produced from Acid Salts by elirrnation of 4 equivs. of Water. ACIDS. - AMIDES. ANILIDES. NITRILES. ANILO-NITRILES. AMIDOGEN-ACIDS. ANILIDOGEN-ACIDS. IMIDES.ANILIMIDES or ANILES. Carbonic acid . . c 0,. Bisulphide of Carboi c s,. Carbamide H N C 0. .. .. Carbanilidec1 H6N c 0. Sulphocarbanilidec, H6N c s. .. .. .. .. *. .. .. Carbamic acid H CO,; H N CO .. .. Carbanilic or Anthranilic acid H CO,; Cl H6 N CO *. .. .. Cyanic acid H N 2 CO. Sulphocyanic acid H N 2CS. 1 Anilo-cyanic acid (carbanile)C, H N 2 CO Oxalic acid . . . Oxamide Oxanilide Oxalonitrile .. .. Oxamic acid H c 0,. Formic acid . . H C H 0,. Acetic acid . . 2 N c 0,. .. Acetamide C12 H N C 0,. Formanilide c12 H6 N~c2 O2* .. .. (Cyanog en) C N. Formonitrile (Hydrocyanic acid) C N H. Acetonitrile H c 04; H N c 0,. H C4 H 0,. H N (34 H3 0 (Cyanide of methyl) Metacetonic acid . Metacetamide .. .. Metacetonitrilec N c H3. H c6 H 04 HZ N>c6 H&0 (Cyanide of ethyl) Butyric acid .H C H 0,. Valerianic acid . . H Clo Hg 04. Caproic acid H c,,H, 04. ButyramideH N C H70 Valeramide H,N c, Hg 0 .. .. .. .. .. .. .. a. Bu tyronitrile (Cyanide of metethy! Valeronitrile (Cyanide of butyl) Capronitrile(Cyanide of amyl) C,N C,H,. c2N Y c.BHP c,N c H,. Benzoic acid . H c,4 H 04* H,c, H, 04. Cuminic acid . Benzamide 3 N,c,,H 0 3 N c H, 0 Cuminamide Benzonitrile (Cyanide of phenyl) Cumonitrile C,N,C ,,B c2 N c1.0 Hll c N c, H,. .. .. .. .I. .. .. .. .. Cinnamic acid . . .. .. .. .. H c, H7 04. Anisic acid . . Anisamide .. .. HY c16 H7 66. 3 N c16 H70 Succinic acid . . H C H 0,. Suberic acid . . . Succinamide 3* N C H 0,. Suberamide .. .. .. .. *. .. .. a. Succinanilic acid IH C H 0,;C, H6 N (7 H2 0,. Suberanilic acid Succinimide H N 2 C4H 0 Phtalic acid .. . . H C H,0,. H9 c H6 O4. I2 N c H6 OZ. .. .. .. .. .. .. Phtalamic acid H C H 0,i H N C H 0 Phtalanilic acid H C8H 0 ; C, H6N Cs H 0,. HY cS H6 O4 ;c,2 H6 N c8 H 02. Phtalimi de H N 2 C,H 0 Camphoric acid . Sulphuric acid . . . H SO,. H C,o H 04- .. Sulphamide €3 N,SO,. .. .. .. ". .. .. .. .. .I '9 '10 Camphoramic acid Sulphamic acid H7 O4 ;H2 N9 c,O H7 H SO ;H N SO,. O2* HY Camphoranilic acid Sulphanilic acid '10 H7 O,; c12 H6 N c10 H7 H so4;c, H N so,. 02a Camphorimide. H N 2 C10 H7 02 TO FACE PAGE 331. VOLATILE ORGANIC BASES. alcohols in a relation similar to that existing between salicylic acid and phenole. It would be interesting to ascertain whether these acids do not exhibit a similar deportment and whether a passage cannot be effected in this manner from glycycin into the methyl- from sarcosin into the ethyl- and from leucin into the amyl- series.VII.-ACTIONOF ANHYDROUS PHOSPHORIC ACID ON VARIOUS ANILINE-SALTS AND ANILIDES. THEsalts of oxide of ammonium both neutral and acid when sub- jected to the influence of heat lose either 2 or 4 equivs. of water ; four classes of compounds being thus produced; neutral oxalate of oxide of ammonium by the loss of 2 equivs. of water becomes oxamide while by the elimination of 4equivs. of water cyanogen or oxalo-nitrile is formed. Binoxalate of ammonia when losing 2 equivs. of water is converted into oxamic acid; a compound arising from the binoxalate by the loss of 4 equivs. of water has not as yet been formed; this term however is found to be represented among the derivatives of the ammonia-salts of various other acids e.g. of cam-phoric and pthalic acids camphorimide and pthalimide being bicam- phorate and biphtalate of ammonia -4 eqnivs. of water. We may thus distinguish as derived from the ammonia-salts by loss of water 1. Amides. 2. Nitriles. 3. Amidogen-acids. 4. Imidogen-compounds. (Imides.) The researches of the last three years have shown that in the salts of organic bases resembling those of ammonia in so many respects the analogy extends also to the faculty of giving up a certain amount of water when subjected to the action of heat. The experiments from which our knowledge respecting this deportment of organic bases is derived have been chiefly performed with aniline and the extent to which the various terms are even now represented in the aniline-series could not perhaps be better illustrated than by the following synopticsl table in which I have placed the derivatives of ammonia and of aniline side by side.(See Table). A glance at this table shows that both the amides and the amidogcn- acids are pretty numerously represented in the aniline-series. Less frequently in this series do the imidogen-compounds appear of which 22 332 DR. HOFMANN ON THE however the number is on the increase the preceding paper having pointed out the existence of a new member both in the aniline- and melaniline-family (anilocyanic acid and melanoximide) .There is only one column in this table in which the spaces for the aniline- terms are altogetheZ vacant i. e. the column for the anilo-nitriles ; there is no compound known which is derived from a neutral aniline- salt by the elimination of 4 equivs. of water. The following experiments were undertaken in order to fill up this gap. My attention was first directed to the dehydration of oxalate of aniline. This salt as is well known when subjected to dry distilla- tion loses like the corresponding ammonia-compound 2 equivs. of water oxanilide being formed. The removal of two additional water- equivalents woiild have given rise to the formation of a compound corresponding to cyanogen or oxalonitrile. Such a compound anilo- cyanogen aniloxalonitrile C, H N,=Cy C, H, I have tried to obtain by the various methods which have been successfully employed in the formation of cyanogen from oxalate of ammonia.Oxalate of aniline as well as oxanilide were repeatedly subjected to rayid distil- lation either alone or with anhydrous baryta with protochloride of zinc or with anhydrous phosphoric acid. The results of these experi- inents were far from what I expected. Oxanilide when distilled alone was volatilized almost without decomposition only an exceed- ingly small quantity of an odorous oil being produced. In the treatment with anhydrous baryta aniline chiefly is evolved ; while by the action of protochloride of zinc and of anhydrous phosphoric acid nearly the whole mass is charred carbonic acid and carbonic oxide being evolved at the same time.In these latter processes however and more particularly in the distillation of oxanilide with anhydrous phosphoric acid the oil which I mentioned before is generated in somewhat larger quantity a crystalline deposit being formed at the same time in the neck of the retort. At the time when I first performed these experiments I imagined that the odorous compound in question was the cyanogen of the aniline-series derived from oxalate of aniline in the same manner as cyanogen itself arises from oxalate of oxide ammonium H,N HC,O4-4H0 = C N. C, H N H C 0 -4 HO = Ci4 H4 N. But unable to procure even by the sacrifice of several ounces of oxanilide a quantity of this compound sufficient to establish its nature either by analysis or the study of its reactions I was obliged to desist at the time from a farther prosecution of the inquiry.VOLATILE ORGANIC BASES. It was not until I had irivestigated the derivatives of dicyano- melaniline that I became acquainted with the actual composition of the body in question But having once obtained anilocyanic acid in the destructive distillation of melanoxiniide there was no difficulty in recognizing that the compound formed in treating oxanilide with anhydrous phosphoric acid is nothing but the same anilocyanic acid. The odour could not leave the slightest doubt upon this point but small though the quantity of oil was which I obtained in distilling oxanilide it sufficed to repeat with this product the principal reactions of anilocyanic acid which I have enumerated in the preceding paper ; so that I have not the slightest hesitation in asserting their identity although I cannot offer the conclusive test of a combustion.The exceedingly small quantity of anilocyanic acid formed in this process quite disproportionate to the amount of oxalate of aniline or oxanilide employed shows that its formation is by no means due to a regular reaytion but to a complicated decomposition in which the largest quantity of the oxanilide is actually destroyed a circumstance which is clearly proved by the large quantity of charcoal separated in the process. The crystals in the neck of the retort are nothing but carbanilide mixed with a small quantity of oxanilide which has escaped decomposition.The formation of carbanilide is simply due to the simultaneous evolution of some aniline which meeting with the vapour of anilocyanic acid gives at once rise to the production of this compound. The formation of anilocyanic acid and carbanilide is supported moreover by the products arising from the destructive distillation of oxamide in which together with carbonic oxide cyanogen and h ydrocyanic acid we invariably observe cyanic acid and ammonia which we find again in the neck cf the retort in the form of urea (bicarbamide). It is not difficult to see in what manner anilocyanic acid is derived from oxanilide these two substances differing only by 1 eq. of hydro- gen which the latter contains in excess. Oxanilide.Anilocykic acid. The removal of this hydrogen may be effected in various ways; we may suppose e. e;. that it is consumedin the regeneration of an equi- valent of aniline 2 C, H N 0 =C, H5 N 0 +C, H N +2 CO. v-+ Oxanilide. Anilocpanic acid. Aniline. DR. HOFMANN ON THE There must however be other modes for if aniline and anilocyanic acid were eliminated in equal equivalents the whole would be obtained in the form of carbanilide no free anilocyanic acid being per-cepti ble.* The chief result then of the preceding experiments is that under those circumstances which induce the elimination of 4 equivs. of water from an ammonia-salt no corresponding aniline-compound is produced. I have performed a series of perfectly similar experiments with benzoate of aniline and benzanilide.Under the influence of phos-phoric acid or protochloride of zinc which so readily effect the conversion of benzoate of ammonia or benzamide into benzonitrile the corresponding aniline-compounds are altogether charred. In no manner did I succeed in obtaining the aniline-term representing benzonitrile. What then may we ask is the reason why aniline which so faith-fully imitates all the habits of ammonia refuses to follow its example with respect to the formation of the nitriles? The answer to this question involves a careful consideration of the constitution of aniline and the analogous bases. In a former paper? I have given a synopsis of all the facts sup- porting the view of Berzelius that the organic bases are conjugated ammonia-compounds in which ammonia pre-exists.According to this view which was in perfect accordance with all the observations which had then been made aniline is represented by the formula H N (Cl2 H*h and an aniline-salt e. g. the oxalate by the formula H N G2 H4) H c 0,-This formula gives no satisfactory answer to the above question. There is no comprehensible reason why the oxalate of ammonia in the aniline-salt should not be deprived of its four equivalents of water and why the residuary cyanogen should not be associated with the usual adjunct. We possess however another view respecting the nature of the organic bases. According to Liebig’s ideas these substances have to be considered as amidogen-compounds. In regarding aniline as an * In the paper on cyaniline (Chem.SOC. Qu. J. I. 159). I have mentioned that the remarkable odour (of anilocyanic acid) is strongly evolved in the treatment of this base with acids. This is now intelligible if we recollect that the same reaction gives rise to the formation of oxanilide. i-Chem. SOC. Qu. J. I. 285. VOLATILE ORGANIC BASES. aniidogen-compound the question appears under a perfectly diferent light. In representing aniline by the formula and the aniline-salts e. g. the oxalate and binoxalate by the formulz we may understand without difficulty that under the influence of dehydrating agents the latter may lose either 2 or 4 equivs. of water (formation of anilidogen-acids or imidogen-compounds) ; we under-stand farther that the neutral salt may lose 2 equivs.of water (in thc formation of oxanilide) but we see with the same facility that the elimination of 4 equivs. of water from the neutral salt is altogether impossible without the destruction of the term Cl2€3 (phenyl) replacing the third equiv. of hydrogen in the ammonia only 3 equivs. of hydrogen being without the parenthesis. It is probable that considerations like those developed in the pre- ceding pages will materially assist in the elaboration of more rational views respecting the constitution of the organic bases. The apparent impossibility of obtaining an anilocyanogen throws some doubt on the pre-existence of ammonia in aniline. It is probably more in con- formity with truth to consider aniline as a substitution-product as ammonia in which part of the hydrogen is replaced by phenyl and this opinion may perhaps meet with the approbation of the Society if I mention that a series of researches on the action of the brornides of the alcohol-radicals on aniline and on ammonia have enabled me actually to replace the basic hydrogen of these substances equivalent for equivalent by the alcohol-radicals and to produce in this manner a numerous series of new alkaloids which appcar to admit of no other mode of interpretation.

ISSN:1743-6893    

DOI:10.1039/QJ8500200300

出版商:RSC    

年代:1850

数据来源: RSC

摘要:

MESSRS. THOENTON AND W. HERAPATH Nov. 19 1849. Thomas Graham Esq, Vice-president in the Chair. The Donations announced were <‘On the use of the Blow-pipe,” by Professor Plattner. Translated by J. S. Muspratt Ph.D, from the Translator. Taylor’s Calendar of the Meetings of Scientific Bodies for 1849-1850,” from the Author. “The new and admirable case of settinge of lime 1601,” being a reprint from Mr. J. C. Nesbitt. The following papers were read XXXI.-On the Waters of the Dead Sea. By MR. THORNTON AND J. HERAPATH HERAPATH, WILLIAM EsQ.,F.C.S. PRESIDENT OF THE BRISTOL PHILOSOPHICAL AND LITERARY SOCIETY AND LECTURER ON CHEMISTRY AND TOXICOLOGY AT THE BRISTOL SCHOOL OF WEDICINE &C. &C. THEDead Sea or as it is called by the Arabs Bahr Lout (Lot’s Sea) though somewhat insignificant in size has nevertheless in consequence of the extraordinary physical character of its waters and the awe and mystery which ancient tradition has thrown around its history attracted the attention of mankind from time immemorial.Under the several appellations of the “Salt Sea,” (Num. xxxiv 3; Deut iii 17; Josh. xv 5);the “Sea of the Plains,’’ (Deut. iv 49) ; and the “East Sea,” (Ezek. xlvii 18; Joel ii 20),frequent mention of it is to be met with in the Holy Scriptures; and in fact it is now supposed to occupy the site of the cities of Sodom and Gomorrah the destruction of which by the wrath of the Almighty is so graphi-cally described in the eighteenth chapter of Genesis. In the works of the Greek and Roman authors again it is often referred to by the name of (‘Lacus Asphaltites,” or the “Bituminous Lake,’’ and many remarks upon the exceeding saltness of its waters and the sterility and desolate aspect of its shores are to be found in the pages of Tacitus and €‘liny.* The lake itself as is well known to every person acquainted with geography is situated in the south of Palestine at no great distance from Jerusalem and is principally supplied by that venerated stream * Tacitus lib.v Hist. cap VI; Strabonis Geogr. Plinii lib. v cap. xv and XVI ;see also vol. 11 p. 1107. ON THE WATERS OF THE DEAI) SEA. the Jordan. Its breadth it would appear from a recent survey undertaken by Messrs. Moore and Beke in 1837 is about nine miles and its length according to the same authorities is thirty-nine or forty miles.The latter however is found to vary considerably at different times of the year according to the extent of the influx derived from the Jordan and other tributary rivers.* The bottom these gentlemen found to be rocky and of very unequal depth ranging 120 180 240 and even 480 feet all within the distance of a few yards. With regard to its geological situation the lakeliesin a deep basin of an irregular oblong figure and is surrounded by steep cliffs of naked limestone which on the western side run up to the height of 1,500 and on the eastern to 2,500 feet above the level of the water. On the surface of the sea there is often found floating an immense quantity of asphaltum which is generally carried by the influence of the wind to the western and southern shores where it is carefully collected by the Arabs who use it as pitch and sell it for medicinal purposes.It was this substance which seems to have been employed in ancient times by the Egyptians to a very great extent for embalming bodies. There are also several mines of sulphur and rock-salt in the sides of the mountains on the western coast which not only afford supplies of those useful articles to the Arabs but even to the inhabitants of the Holy City. Indeed many travel- lers have stated that the remarkable saltness of the waters is prin- cipally occasioned by the existence of similar saline formations at the bottom of the sea. SO deeply in fact is the surrounding soil impregnated with this ingredient that few or no vegetables will grow there and it is from this circumstance combined with the absence of all animal life either in the waters or on the shore that recent travellers have conferred upon the lake the name u Mare Mortuum,” or the Dead Sea.The water like that of the sea is stated to be of a deep blue colour shaded with green ;but it is considerably more salt and intoler- ably nauseous and bitter to the taste. Rae Wilson who wrote some years ago describes it to be not unlike the Harrowgate waters in taste and smell but more disagreeable ;although it approached more closely in character to bilge-water. Its specific gravityis so great that it is almost impossible for a man to sink in it ;persons who are entirely unacquainted with swimming can lie sit or swim in it with the greateFt ease.Josephus relates that the Emperor Vespasian for the * It is more than probable that its dimensions have become contracted in modern times as if we niay believe Josephus at the period when he wrote it was 72 miles long by 18 broad. 338 MESSRS. THORNTON AND W. HERAPATH sake of an experiment caused certain men to be thrown into this sea with their hands and feet bound with cords and they floated on the surface. Bathers in this lake however experience a curious sensation of the eyes which has been described by Mr. Legh as temporary blindness; and upon getting out of the water evaporation proceeds only very slowly leaving a thick oily incrustation of salt adherent to the skin which remains for many days as it is impossible to remove it com-pletely even by repeated ablution.Notwithstanding however that the most obvious peculiarities of the water of the Dead Sea have been known and recognizedfor many ages it has only been in comparatively modern times that scientific men have attempted its chemical examination. Within the present century Lavoisier Marcet Klaproth Gay-Lussac Gmelin and Apjohn have each analysed it. The celebrated Lavoisier experimented upon it in conjunction with his no less renowned countrymen MM. Macquer and Sage,* in the year 1778 (videTable). At that early period however analytical chemistry had not attained to such a degree of accuracy as that of which it is now susceptible and consequently there is little or no doubt but that they must have overlooked many of the most im-portant constituents.The same remarks apply to all of the three analyses which follow next in the series ; namely that of Dr. Mar-cet in 1807 of Professor Klaproth and of M. Gay-Lussac in 1818. The former of these analysts was moreover inconvenienced by the smallness of the quantity which he operated upon which did not amount to more than an ounce and a half. The great differences which are to be observed in Professor Klap- roth’s numbers (tide Table) as compared with those obtained by the other two experimenters according to Dr. Marcet are occasioned by that chemist having employed too low a temperature for the purpose of desiccation. The last two analyses of these waters that have been published are those by Professor Gmelin of Tubingen and by Dr.Apjohn of Dublin. The former appeared in the year 1826 and the latter in 1837; they are given in the synoptical table at the end.? On comparing the results of these six analyses it will be seen that in no two instances do they agree either in the proportion or composition of the contained salts. The two latter by Gmelin arid Bp-* MCmoires de l’iicad6mie des Sciences p. 69. -f-An analysis by Dr. R. Marcharid appeared this year in lhe Journ. fur prakt. (,liein. B. XLVII. %%--ED. ON THE WATERS OF THE DEAD SEA. john are evidently the ones most to be depended upon for the reasons already stated; but even between these many very great differences occur.The lower specific gravity of Apjohn’s specimen which was occasioned by its having been collected at the close of the rainy season and at about half a mile’s distance from the mouth of the Jordan may it is true partly account for these but it certainly will not explain the absence of the chlorides of aluminum and ammonium both of which were found by Gmelin the former particularly in rather considerable quantity. For these reasons it was therefore obvious that another analysis of the waters performed with all the care and precautions that are now usually employed in this species of investigation was absolutely necessary in order that we might be enabled to determine which of the above analyses was the most trustworthy or to point out the cause or causes which led to the discrepancies observed.Consequently when Mr. C. J. Monk (son of the venerable Bishop of Gloucester and Bristol) who has recently returned from a long journey in Syria and the Holy Land kindly offered to place at our disposal for this purpose a bottle of the water we most willingly acceded to his proposal with what result the following pages must testify. The specimen so presented to us was collected by Mr. Monk himself on the 10th of March last near the north-western extremity of the lake about half a mile from the spot where the Jordan enters but quite apart from all direct influence arising from the stream of fresh water which flows into it. I. PRELIMINARY EXAMINATION. The water was perfectly clear and colourless and did not deposit any crystals on standing in closed vessels even when cooled considerably below its ordinary temperature.Its taste as we have before observed was intensely bitter and nauseous and when swallowed even in small quantity it produced a sensation bordering upon sick- ness. It possessed no unpleasant odour. Its specific gravity at 66O F. was 1.17205. The boiling-point as determined in a glass vessel with the barometer at 29.74 inches and the thermometer at 47.75O was 221.75O F.* It did not exert any definite reaction upon either blue or reddened litmus-paper proving the absence of all uncombined acid and carbonated alkali; neither did it in the slightest degree affect acetate-of-lead-paper as from Rae Wilson’s statement we should have expected it.Only the slightest per-ceptible opalescence was produced in it upon boiling or on the * Dr. Apjohn found that of his specimen to be 2210. 340 MESSRS. THORNTON AND W. HERAPATH addition of an ammoniacal solution of chloride of calcium when in the latter case care was taken to add previously a sufficient quan- tity of muriate of ammonia to prevent the precipitation of the magnesia. Consequently only the faintest traces of carbonic acid or carbonate of lime were present. The chloride of gold test of Dupasquier gave unmistakeable proofs of the existence of an abnormal proportion of organic matter. Other reagents showed that it likewise contained magnesia or magnesiuni lime alumina the oxides of iron and manganese soda potash and ammonia; also chlorine bromine and sulphuric acid with traces of silica bitumen and iodine.The latter occurred only in exceedingly minute proportion. 11. QUANTITATIVE ANALYSIS. A. Determination of the entire amount of saline ingredients. Great care was requisite in this part of the investigation in order to avoid loss from the evolution of hydrochloric acid by the decomposition of the earthy and Eetallic chlorides at the high temperature to which it was necessary to expose the saline residue previously to weighing. This source of error was obviated by mixing a known weight of perfectly pure and anhydrous carbonate of soda with the water prior to evaporation. Weight of water taken. I. 1281.9296grs. Na 0 CO em-ploged. 229.53 Saline residue obtained.53 7.727 True percentage of salts. 24.03998 11. 1709-2395 , 306.04 717.256 24.05668 Mean . 24*04833* B. Estimation of the Organic Matters. The saline residue from the first experiment which had been dried at a temperature of 350° F. was repeatedly extracted with boiling water and the solution evaporated to dryness. The dried matters which remained behind were then finely powdered again dried for many hours at 350° F. and afterwards heated to redness. The loss amounted to 0*792=0.06173per cent of organic matters in the water. The residue from the second experiment (A.11.) was employed in testing for the organic acids; not the slightest trace however of crenic or apocrenic acid could be detected. * Even this determination however it will be hereafter seen is somewhat below the truth on account of the sublimation of a small quantity of sesquicarbonate of ammonia produced by the action of t.he carbonate of soda on the chloride of ammonium con- tained in the water.ON THE WATERS OF THE DEAD SEA. C. Examination for Nitric Acid. In this attempt we made use of the test which has been lately described by M. Lassaigne.* A known quantity of the water was evaporated to dryness. The salts thus obtained were then reduced to a fine powder and treated several times in succession with boiling alcohol sp. gr. 0-8010 until everything soluble in that menstruum was extracted The alcoholic solution having been then introduced into a retort and the greater part of the alcohol removed by distilla-tion the remainder was evaporated to the consistence of a syrup and treated with a large excess of recently-precipitated tribasic-phosphate of silver.A moderately large quantity of water was then added and the chloride bromide and excess of phosphate of silver separated by filtration. Upon testing the filtered solution wlth an alkaline chlo-ride only a very slight degree of opacity was produced and even this in all probability was caused by the presence of a small quantity of the phosphate of silver which is known to be not perfectly insoluble in water. It may be observed that in a comparative experiment undertaken in order to ascertain the value of this test we could readily detect and estimate quantitatively the nitric acid when 0.01 gr.of nitrate of potash was added to 970 grs. of a mixture of chloride of sodium and sulphate of soda. The same negative results as to the presence of nitric acid in the water were obtained by our own process described in thelast number of the Quarterly Journal of the Society (No. VII. p. 203). D. Determination of the Sulphuric Acid Chlorine and Bromine. a. 1709.2395 grs. of the water were precipitated by nitrate of baryta ; we obtained of sulphate of baryta 2.013grs. = 0.68235gr. of sulphuric acid= 0.039921 per cent. b. The filtered solution was acidified with nitric acid and an excess of nitrate of silver added ; the mixed precipitate of chloride and bro-mide of silver produced weighed 1060 784 grains. This matter wa.s then heated to redness in a current of dry chlorine gas and the loss of weight noted; it amounted to 2,004grs.It therefore contained of Percentage of water Chlorine . . 262.97838 gr8. = 15-44420 Bromine . . 3.72041 , - 0.21767 We likewise examined the water for iodine both by the ordinary test of nitrate of palladium and also by that of starch and sulphuric * Coniptes Rendus August 13. 1849 also see Chein. Gaz. vol. VLI. p. 363 MESSES. THORNTON AND W. HERAPATH acid adopting the precautions mentioned by Dr. Cantii;* but only very faint aud doubtful traces could be discovered. €3. Estimation of the Alumina and the Oxides of Iron and Manganese. The alumina was precipitated in the first instance with the iron and manganese as sulphureh the latter were afterwards peroxidized and separated from each other in the ordinary manner.1709.2395 grains of the water gave a precipitate of the three oxides which weighed 0.465 gr. This contained of Per cent of water. Fe 0 . . 0.029 = 0.001697 Mn 0 . . 0.064 = 0.003745 Al 0 . . 0.379 = 0.022174 F. Estimation of the lime and magnesia. Per centage Water taken. Carbonate of Lime. Lime. in water. 38.320 grs. = 21.45903 = 1*255474 1709.2395{ Pyropliosphate of magnesia. Magnesia. 154.820 grs. = 56.68233 = 3.313890 G. Estimation of the potash and soda. Mixed alkaline Potasssio-chloride potassium' Water taken. chlorides. of platinum. 20.8075 grs. Chloride sodium. 1709,2395 227.792 grs. 67.627 = 20609845grs. I This quantity of water therefore contained of Potash 13-141542 = 0.768853 per cent.Soda . 110,391596 = 6.458519 , H. Estimation of the ammonia. 2563.8590 grs. of the water distilled with an excess of caustic potash yielded ammonio-chloride of platinum 0.681 gr. = 0.04591 gr. of ammonia = 0-001791per cent in the water. ~ ~ ~~~ ~ Now upon collecting together the above numbers it will be seen that 100 parts of the water of the Dead Sea yielded of Organic matter (R) . . . 0°061730 Sulphuric acid (D.a.) . 0.039921 Chlorine (D.b.) . . 15.444200 rn Bromine . . Om2l767O Peroxide of iron (23) . . 0.001697 Sesquioxide of manganese . . 0.003746 Alumina . 0.022174 Lime (F) . I . 1.255472 Magnesia . . 3.313890 Potash (G) .. 0,768853 Soda . . 6.458519 Ammonia(H) . 0.001791 * Raccolta Pisico-Chemica Italiana No. XXVIII. 1848. See also Chem. Gaz. vol. vr. p. 394 343 ON THE WATERS OF THE DEAD SEA. Consequently its true composition will be Chloride of calcium . . 2.455055 per cent Chloride of magnesium . . . 7.822007 , Bromide of magnesium . . 0.251173 , Iodide of magnesium . . doubtful traces Chloride of sodium . . . 1201.09724 per cent Chloride of potassium . . . 1*217350 J Chloride of ammonium . . 0.005999 , Chloride of aluminum . . . 0.055944 , Chloride of manganese . . . 0.005998 , Chloride of iron . . . 0.002718 , Organic matter (nitrogenous) . . 0.061730 , Nitric acid . . very doubtful traces Carbonate of lime .. faint trace* Sulphate of lime . . . 0 067866 per cent Silica . . . traces Bituminous matter ditto 24055564 Total amount of salt as determined by actual experiment . . 24°0483301. We shall refrain from entering upon any comparison of our analysis with those previously published ; but shall content ourselves with calling the attention of the members to the subjoined synoptical table ; a glance at which will enable them to arrive at a much more correct idea as to the correspondence of the several results than any amount of words would do. * After the above analysis was concluded a further proof of the existence of carbonate of lime in the water was obtained in the following manner. Upon casually examining the sides of the empty bottle by transmitted light a very small quantity of a grey floc-culent substance was seen adhering to the inner surfaces ; and this being separated by means of a clean caoutchouc washer and a few drops of distilled water was found to weigh 0.029 gr.(per quart). When examined chemically it effervesced upon the ad- dition of a diluted acid and the solution was precipitated by oxalate of ammonia &c. in the same manner as lime. No effect was produced either by ammonia or the triple phosphate of soda and ammonia ; it therefore did not contain alumina oxide of iron or magnesia. -/-Close as is the approximation between these two determinations yet if we take into consideration the small loss which must naturally have taken place in the second instance from the evolution of the ammoniacal salts it will be seen to be really still more so.Thus upon reference to p. 340 we shall find as the mean of experiments that 1495.5845 grs. of the water plus 267.785 grs. of NaO CO, gave 627,4915 grs. of saline residue. Now subsequent experiment (p. 342) proved that this quantity of water must have contained of NH, 0-02678 gr. which is equivalent to 0,092963 gr. of 2 NEI, 3 CO,+ 2 HO. Consequently 627.584463 (627.491500 + 0.092963) -267.785 (the weight of NaO CO employed) = 359.799463 grs. represent the true weight of the salt contained in that quantity of the water which is equal to 24.05745 per cent. TABLE GIVING THE COMPOSITION PER GALLON OF THE WATERS OF THE DEAD SEA AS SBOV" BY THE ANALYSES OF DIFFERENT CHEMISTS.VIM.Lavoi-Prof. M. Gay-Messrs. ?r Macquier Dr. Marcet. Klaproth. Lussac. hof. Gmelin. Dr. Apjohn. Herapath. z and Sage. Y Specific gravity ... 1'2403 1'2110 1'2450 1'2283 1'2120 1'1530 1'17205 Ff! Boiling-point ... ndetermined indetermined indetermined indetermined indetermined. 2210 22l0'75 _-Chloride of calcium 33'122'2115 * 3'221'2600 9 237'900 3'439 2400 2'7 2 6'8 424 1'967'7098 2'014'2129 5 *I 4 , ,,magnesium . . .8'561'7700 2 1'090'300 13'163'6911 9 988.5526 5'94 8'3270 6.4 17'6780 M Bromide of magnesium . . .. .. .. .. .. .. .. .. 372' 7 0 22 162'2272 206-0708 Iodide of magnesium ? . .. .. *. .. .. .. .. .. .. very minute o traces. Chloride of potassium .. .. .. .. .. 1'420 0519 687 6492 998.7570 r., , sodium. .. k:4 26.3 125 9'050'04 52 6.1 70.220 6 004-7206 6 326'8569 9'935'2036 M , ,,ammonium .. .. .. .. .. .. 6'1084 .. .. 4'9226 m. , , aluminum .. .. .. .. .. .. *. .. .. 76.0167 .. 45'8975 M ),iron . .. .. .. .. .. .. .. .. .. .. .. .. 22304 & , , manganese .. .. .. .. .. .. .. .. .. 179'6063 4'0355 4'9216 u1 Organic matters . .. .. .. .. .. .. .. .. .. .. .. 50'6510 M Nitric acid . . .. .. .. .. .. .. .. .. .. .. .. .. .. loubtful traces P Carbonate of lime . .. .. .. .. .-.. *. .. .. .. .. .. traces. Sulphate of lime . .. .. .. 45-77588 .. .. .. .. 44'7107 60.5 5 55 6800 Silica and bitumen .. .. .. .. .. .. .. .. .. .. .. .. traces. 1. Fixed salts . . .. 38* 54 8'5240 20'878'8510 36'498.420 22'578'6106 20'8 19'31 18 15'157 3380 19736.52 54 Water ... .. 48 272-4760 63'89 1' 1490 50'651'580 63'402.38 94 64'020'6882 65'552'6620 62'306'9690 ~ ~ 84'7 7O.OOOO 87*150 000 85'98 1'0000 84 840 0000 80'7 10*0000 82'043'4944

ISSN:1743-6893    

DOI:10.1039/QJ8500200336

出版商:RSC    

年代:1850

数据来源: RSC

摘要:

MR BRANDE ON THE WELL-WATER OF THE ROYAL MINT. 346 XXXIL-Analysis of the Well-Water at the Royal Mint with some Remarks on the Waters of the London Wells. BRANDE, BY WILLIAM THOMAS EsQ.,F.R.S. V.P.C.S. &c. Previous to the year 1842 the Mint was supplied with water principally from two sources the dwelling-houses offices and a part of the works by the New River Company; and the steam engines by wells partly supplied by so-called land-springs and partly by a tunnel communicating with the Tower Moat ; the prin- cipal supplies being derived from the latter ; so that when in conse-quence of any works carrying on at the Tower the access of the river to the moat was impeded the operations of the Mint were not unfrequently obliged to be suspended ; besides which the water derived from that source was always muddy and often very foul and offensive.In consequence of this bad condition of the water in the Tower Moat and the effluvia arising from it in hot weather it was resolved in the year 1843 to drain and lay it dry. The Mint was accord- ingly altogether deprived of its supply of water from that source and the land springs supplying the wells of the several steam engines to say nothing of the impurity and hardness of the water thence derived were found wholly inadequate to the wants of the engines. It therefore became necessary to have recourse to the New River Company for such additional supplies of water as might be wanted for carrying on the business of the Mint; and for this their charges as far as the steam engines were concerned were at the rate of 3210 per horse power per annum; but from various causes these supplies could not always be depended on so that on several occasious a temporary suspension of the business of the Mint was the consequence of a deficient supply of water.Under these circumstances it became my duty to suggest to the Master of the Mint the adoption of such measures as might ensure for the future a regular and adequate supply of water for the use of the whole establishment and to this end it was necessary in the first instance to make myself accurately acquainted with the actual condition of the several wells existing in the Mint and with the quantity and quality of the water which might be derived from them.I was therefore authorised by the Master of the Mint to consult with Mr. Thomas Clark an experienced Well Engineer in reference to the subject; and I accordingly desired him to examine into the VOL. 11.-NO. VIII. AA MR. BRANDE ON THE condition and capabilities of all the wells shafts and tunnels con- nected with the supplies of water throughout the building. This examination was carefully and effectually accomplished ; and it appeared that the several wells were in a very dilapidated and some of them in a very dangerous state; that few of them were so situated or conditioned as to admit of being sufficiently or safely deepened so as to yield an adequate supply of water; and that as respected the wells in the several engine-houses they were mere reservoirs connected with the tunnel-shaft from the Tower and therefore almost exclusively supplied from the muddy source of the Tower Moat.Having personally convinced myself of the correctness of this Report and having had Mr. Clark’s statement corroborated by Mr. George Rennie I represented the matter in detail to the Master of the Mint and suggested three plans for consideration namely 1. To derive the requisite supplies of water from the Water Companies. 2. To repair the present wells and to deepen such of them as would admit of that operation. 3. To sink an entirely new well and I strongly urged the adoption of the latter alternative which after due consideration was agreed to. I there-fore obtained proper plans and estimates from Mr.Clark which after having been submitted to the Board of Woods and by their direction to Major Jebb were ultimately ordered to be carried into execution. These plans included the sinking of an entirely new well; the erection of a capacious water-tank at a sufficient height to supply the ordinary demands of the Mint ; proper pumps for raising the water and mains for distributing it over all parts of the buildings; together with fire-cocks and other arrangements the details of which would be irrelevant to the object of this communication. It may be right to premise that the total depth of this new well is about 426 feet; that the depth from the surface down to the chalk is about 224 feet; and the borings into the chalk about 202 feet ; the following being the well-sinkers’ accoirnt of the strata gone through ;namely Feet.Made earth . . 11 Gravel and sand (with water) . 13 Blue clay with a few sandy veins (no water) . . 98 Dark sand with veins of clay (little water) . Coloured sand and pebbles (abundance of water) . . . 4 14 WELL-WATER OF THE ROYAL MINT. 347 Mottled clay (dry) . . .6 Loamy sand and dark clay (little water) . *5 Blue clay with shells . . .6 White rock (quite dry) . . .3 Green sandy rock and pebbles (dry) . .3 Loamy green sand and black pebbles (little water) . .5 Green sand and pebbles (abundance of water) . .6 Dark sand with shells . . 40 Flints . . 10 Chalk . . 202 -426 The lining of the upper part of the well through the gravel and nto the blue clay is composed of stout cast iron cylinders 1i inch thick and 8feet clear diameter; they are made in 5 feet lengths with internal flanges 3 inches wide packed and jointed with strong bolts and nuts these prevent all access of the land springs from above.The shaft is then steined to the depth of 88 feet (that is nearly through the blue clay) in 9-inch cemented brickwork; after which cast iron cylinders are resumed of 7 feet diameter and these are continued down to the chalk ; but after passing through the stratum of mottled clay they include a series of cylinders of 6 feet diameter the space between the outer and inner cylinders being filled with gravel-pebbles; a bore-pipe 20 inches diameter and 45 feet long is then driven to about 10 feet into the chalk and through this the boring is continued by an 18-inch auger to the entire depth of the well.This well and all the works connected with it were completed at Christmas 1846 and on the 1st of January 1847 the whole of the works of the Mint and the dwelling-houses were supplied with the water which is raised in a 6-inch main to a height of 50 feet above the surface or 130 feet above the average level of the water in the well ;and is delivered at the rate of 240 gallons per minute by means of three pumps of 9-inch diameter and 8-inch stroke into a tank supported upon a building of brickwork. This tank is 100feet long 30 wide and 5 deep; it contains therefore 15,000 cubic feet of water or 93,750 imperial gallons. Two 6-inch cast-iron mains furnished with proper slide valves descend from this tank one passing on either side of the Mint so as conveniently to supply the whole of the establishment the daily consumption of water fre-AA2 348 MR BRANDE ON THE quently exceeding 40,000 gallons j besides which a daily supply of about 6,000 gallons is delivered by means of a main laid from the Mint across Tower Hill to the Tower for the use of the inhabitants and the garrison; there being at present no serviceable wells in that fortress and the water derived from the adjacent river being ob-jectionable in point of cleanliness.The average height which the water attains in the shaft of the Mint well is 80 feet from the surface. After a day’s pumping it is lowered upon an average 20 feet but there it remains stationary the flow of water from below maintaining the level or in other words delivering at the rate of about 240 gallons per minute.Before this well was completed and before the boring into the chalk had been accomplished the water derived from it contained 44grains of dry saline matter in the imperial gallon. At present the machinery being complete and the well in full and daily use the mean of several experiments in reference to the solid matter contained in the imperial gallon of the water amounts to 37.5 grains. The substances contained in each gallon of the water are as follow Sulphuric acid ..............7.44 Chlorine ................6-31 Carbonic acid (after boiling) .........5.84 Silica ................0.50 Sodium (combined with chlorine) .......4.22 Soda (combined with sulphuric and carbonic acids) ..10.82 Lime ................1.96 Magnesia ...............0.71 Organic matter Phosphoric acid ............traces. Iron The water evaporated to one-fifth of its bulk and filtered had lost almost every trace of lime and of magnesia so that it is probable that the greater part of those substances were held in the state of carbo-nates by excess of carbonic acid. The carbonate of lime forms films during boiling which subside and appear under the microscope in the form of very minute acicular crystals. The crystalline deposit obtained by slowly evaporating the water after the precipitated carbonate of lime has been separated by filtration exhibits under the microscope three distinct forms; namely cubes (of chloride of sodium); prisms which lie distinct upon the other salts and are WELL-WATER OF THE ROYAL MINT.efflorescent (sulphate of soda) ;and small aggregates of rhomboids intermixed with small spherical particles like pin-heads (carbonate of soda). The residue of the evaporation of the water after having been gradually raised to a dull red heat acquired a grey tint and exhaled a slight odour of burning azotized matter; and a piece of moistened turmeric paper held in the evolved vapour was transitorily reddened. I have not been able to detect any potassa in this water; and only a slight indication of the presence of a phosphate in the precipitate deposited by the water during boiling.Upon the whole I am inclined to regard the following as a tolerably correct statement of the proximate saline components of this water Grains in the imperial gallon. Chloride of sodium ..... 10.53 Sulphate of soda ......13.14 Carbonate of soda ...... 8.63 Carbonate of lime ...... 3.50 Carbonate of magnesia .... 1.50 Silica .......... 0.50 Organic matter Iron ...... traces. Phosphoric acid 37.80 The specific gravity of the water at 55O is 10007 Its gaseous contents I have not ascertained. A section of the well accompanies this paper which will shew such details of its construction as I have not thought it necessary to enter into as well as the relative thickness and position of the intersected strata.I have examined the water of several other wells in and about London some of which derive their supplies from the sands under the blue clay and others to a greater or less extent also from borings.into the chalk and I think that in most cases the latter waters are the more pure; that is that in proportion as the borings are deepened into the chalk the less are the solid contents of the water. There are in London and its vicinity some very deep wells which yet do not reach the chalk; and others of a less depth which are carried into it :arising out of inequalities in the surface of the chalk and the varying thickness of the blue clay itself; so that the 350 MR. BRANDE ON THE variations in the relative quantity of solid matter in the waters derived from these wells is no criterion of their respective depths.* The shallow wels of the London district by which I mean those which do not penetrate the blue clay but derive their supplies from the gravels and sands above it yield water of varying quality but always much less pure than that of the deeper wells and generally abounding in sulphate of lime and consequently heminently hard as respects the decomposition of soap and other common ,culinary uses There are many of these wells in which analysis detects indica- tions of contamination by sewers and by the vicinity of gas-pipes; and some of them have been disused and filled up on that account There are also as is well known many which are either in church- yards or upon their boundaries ; and it is from these parish pumps that the neighbourhood often exclusively derive their supply of drinking-water.I am at present examining the waters of several of these wells. In those which I have already examined I have been struck with the abundance of nitrates generally nitrate of lime; and this in some of them is accompanied by what may be termed a large proportion of organic matter; so large indeed that on proceeding in one case to heat the dry residue of the water to redness a deflagration ensued; and yet this water is bright and colourless has no unpleasant taste and is abundantly resorted to as very superior spring-water by a very populous neigh bourhood. How far such waters may or may not be salubrious is not a ques- tion here to be discussed; but in some cases there can I suppose be no doubt upon the subject inasmuch as I have found two of these waters of an evident though slight brown or peaty tinge as furnished from the well; soon becoming brown on evaporation and yielding abundant evidence of containing that species of humie extractive in which the adjacent soil no doubt abounds.I have in 00 instance been able to detect ammoniacal salts in any of these waters but I presume that the nitric acid which they contain is the result of the oxidizenient of ammonia. It was my wish to have laid some of the results of these analyses more in detail before the Society ; my apology for such imperfect details is the hope that they may engage the attention of other analysts ; that the important subject of the condition of the waters of London and its vicinity may meet with the attention it deserves; * The chief peculiarity of these waters is derived from the presence of carbonate of soda which notwithstanding the large relative proportion of other salts which they often con- tain confers upon them a peculiar softness as regards the soap-test,and seems to render them well adapted for domestic use and especially for the infusion of tea and coffee.WELL-WATER OF THE ROYAL MINT. 351 and that the comprehensive subject of the metropolitan supply of water niay be scientifically and accurately and dispassionately considered by those who are adequate to the task. As regards the leading question of River supplies on the one hand and Artesian supplies on the other I cannot however help expressing myself decidedly in favour of the former.Deep wells are pre-eminently valuable for local uses ; but the peculiarities of the waters which they afford; the depth from which in many situations and under most circumstances those waters must be raised; the possibility and I think 1 may say probability of the inadequacy of their supply; and the chances of their mutual interference are some of the circumstances which in my mind should be well weighed before the gigantic scheme of the supply of the metropolis from such sources is seriously entertained. On the other hand pure River-water is already upon the surface in various quarters in unlimited quantity and at no great distance ;and when filtered an operation which as experience has shewn is attainable to any extent its quality is in all respects superior.That many parts of London are badly and inefficiently supplied with water and that in some places none is laid on cannot be denied; but a slight move- ment in a proper direction would I think reniedy all real evils under this head. I must further beg leave to express my opinion in favour of the adequacy of the existing Water Companies to the accomplish- ment of all that can be reasonably required the magnitude of their united means the general excellence of their arrangements the practical skill with which they have been devised and executed and the resources which are still open to them where increase of supply is demanded are the circumstances upon which I found this opinion.I shall conclude with a short comparative table showing the relative quantity of solid matter contained in such river and spring waters as have been carefully analysed; intending upon a future occasion to extend the list to give the details of the analyses and the names of the analysts; in their present imperfect state however the following details will serve to illustrate some of the points touched upon in the preceding notice. The wells which are termed deep derive their water from the strata below the blue clay and some of them penetrate into the chalk; those termed shallow are supplied from the strata above the blue clay. This is the case with most of the common London wells which however are often steined to a considerable depth in the clay for the purpose of forming TC reservoir.PROFESSOR WOHLER ON TITANIUM. Solid matter in the imperial gallon. Thames at Greenwich . . . 27.9 . . 28.0 , London . , Westminster. . . . 244 , Brentford . . . . 19.2 , Twickenham . . . 22.4 , Teddington . 17.4 Average of the Thames between Teddington and Greenwich . 23.2 New River . . . . 19.2 Colne . . . . 21.3 0 Lea . . . . 23.7 Ravensborne at Deptford . . . 20.0 Combe and Delafield’s Brewery Long Acre. Deep well . 56.8 Apothecaries Hall Blackfriars . ditto. . . 45.0 Notting Hill . ditto. . . 60.6 a Royal Mint . . ditto. . . 37.8 Hampstead Waterworks . ditto . * 40.0 Berkeley Square .. ditto. . . 60.0 Tilbury Fort . . . ditto. . . 75.0 Goding’s Brewery (Lambeth) . . ditto. . . 50.0 Ditto . ahallow well . 110.0 More’s Brewery (Old Street) . . deep well * 38.0 Ditto . . shallow well . 110.0 Trafalgar Square Fountains . . deep well . 68.9 Well in St. Paul’s Churchyard . . . 75.0 , Breams Buildings . . . . 115.0 , St. Giles Holborn . . . . 105.0 , St. Martin’s Charing Cross . . 95.0 , Postern Row Tower . . . . 88.0 Artesian well at Grenelle near Paris . . . . 9.86

ISSN:1743-6893    

DOI:10.1039/QJ8500200345

出版商:RSC    

年代:1850

数据来源: RSC

摘要:

PROFESSOR WOHLER ON TITANIUM. XXXIIL-On Titanium. BY PROFESSOR WOHLER. The beautiful copper-coloured cubic crystals of titanium the formation of which have been so often observed in the blast iron- furnaces are not that which we have hitherto considered them; they are not a simple but a compound body. They consist of a combina- tion of cyanide of titanium with nitride of titanium composed according to the formula Ti C N + 3Ti N and contain in 100 parts titanium 78.00 nitrogen 18.11 carbon 3.89; that is they consist of cyanide of titanium 16.21 nitride of titanium 83.72. PROFESSOR W~HLERON TITANIUM. 353 The treatise laid before the Gottingen Society contains the details of the manipulation used in the analysis and the proofs for assuming this composition ;here the author only communicates the behaviour which led to the detection of the carbon and nitrogen.When these cubic crystals are heated in dry chlorine gas liquid chloride of tita-nium is produced; at the same time a crystalline volatile yellow substance sublimes in cansiderable quantity. This substance is a compound of chloride of titanium with chloride of cyanogen which can be directly and easily produced from the two chlorides. At the end of the operation about 1 per cent of residue remains behind consisting of graphite in fine scales; this is however an acci- dental impurity and exact experiments have shown that this graphite plays no part whatever in the formation of the cyanogen. When these crystals are powdered mixed with hydrate of potash and fused ammonia is evolved and titanate of potash is formed.When the crystals are heated to redness in a porcelain tube and the vapour of water in a continuous stream is passed over them a consi- derable quantity of hydrogen gas is set free as observed by Regnault ; but there is also at the same time a disengagement of ammonia and hydrocyanic acid. If this experiment be made with the crystals in their natural state (not powdered) the titanic acid produced main- tains the form of rounded cubes; but under a magnifying power of 300 diameters they have the appearance of an aggregate of crystals the greater part of which present themselves in an entire form; and what is most remarkable this form is identical with that of the mineral Anatase that is they are pointed octahedrons with a square base .possessing a strong lustre and all the peculiarities belonging to this mineral.The cubes when reduced to powder have moreover the remark- able property if mixed with oxide of copper lead or mercury and heated of emitting a lively sparkling flame and reducing the oxides of these metals ;this behaviour was taken advantage of for deter-mining the proportion of carbon in them; the heat evolved is so intense and instantaneous that even copper runs into a globule in the glass tube. With regard to the formation of the crystals in the smelting furnace the writer believes there can be no doubt that it stands in intimate connection with the formation of cyanide of potassium which has been so often observed in these furnaces; some experiments which he undertook to make this if possible more clear fully confirm the supposition.A mixture of ferrocyanide of potassium and titanic acid was exposed in a well-closed crucible for an hour to a heat in which nickel would melt; the result was a brown unfused mass which under a magnifying power of 300 diame- 354 PROFESSOR WOHLER ON TITANIUM. ters presented besides the particles of metallic iron throughout the whole mass a network of copper-coloured strongly metallic shining short prisms which as indicated by the colour are composed of the same substan.ce as the cubic crystals. After removing the iron by means of hydrochloric acid these remained mixed with carbon and exhibited all the properties belonging to the cubic crystals.The titanium used in all these experiments was produced at the Ruebeland smelting-furnace in the Hartz where lately a mass of titanium has been found estimated at 80lbs. (Hanover) weight. The Author has not had an opportunity of examining the crystals from other furnaces but there can be scarcely a doubt that all are perfectly identical in composition. Nitride of Titanium.-As long as the cubic crystals of titanium were considered to be pure titanium it was from their similarity of colour a pardonable fault to regard as the true metal the copper- coloured substance first produced by H. Rose from the double chlo- ride of titanium and ammoniuni by subjecting the same to the action of heat in gaseous ammonia.But this latter substance is likewise not that which we believed it to be but a nitride of titanium com-posed according to the formula Ti N, or more probably Ti N, that is 3 Ti N +Ti N and contains nearly 28 per cent of nitrogen ; also on more accurate comparison a difference in the colour may be perceived; this latter compound being much redder than the cubic crystals which have a tint of yellow; 100 parts gave by combustion only 120 whereas if pure titanium they should yield 166 parts. When fused with hydrate of potash gaseous ammonia was abun- dantly evolved. This is not the only isolated combination of titanium and nitrogen that can be produced; the Author has found that two other com- pounds exist. All these compounds exhibit the same remarkable phenomena as the cubic crystals (viz.under a lively evolution of flame they are oxidized and the metallic oxides reduced) when powdered and mixed with the oxides of the easily reducible metals and subjected to the influence of heat. All these compounds can sustain a tempe- rature at least equal to that in which silver would melt without undergoing decomposition. All give when fused with hydrate of potash gaseous ammonia. The nitride of titanium Ti N is pro-duced when titanic acid is subjected to a strong heat in a stream of gaseous ammonia; its powder is of a dark violet colour with a copper-coloured tint; in small pieces it possesses a violet copper colour and metallic lustre. The nitride of titanium Ti N, or more probably 2 Ti N +T N PROFESSOR WOHLER ON TITANIUIM.355 is produced when Rose's titanium is submitted to the action of a stream of hydrogen at a strong red heat whereby the nitrogen which it gives off is carried away in the form of ammonia; it possesses a metallic lustre and a brassy or almost gold-yellow colour. This compound is obtained (impregnated however with carbon) when titanic acid is heated to redness in a stream of cyanogen gas or in the vapour of hydrocyanic acid; here however it must be remarked that cyanide of titanium is not formed. The Author can also reply to the question-What is the character of pure titanium ? This substance was first observed by Berzelius; it was not however closely examined by him; it is that body which is produced by heating the double fluoride of potassium and titanium with potassium.The Author prepared it in a covered platinum crucible ;the reduction was accompanied by a lively evolution of flame. After washing and separation by water pure titanium remains behind as a dark green uncrystalline and tolerably heavy powder. Even after being subjected to pressure one cannot discern a shade of colour approaching that of copper and under the microscope it ap-peared as a cemented mass having the colour and lustre of iron. If heated in contact with the air it burns with much splendour; sprinkled into a flame it burns at a considerable distance above its point with the same brilliancy and splendour as uranium; if brought to a red heat in oxygen gas it is suddenly consumed with a splendour resembling a discharge of the electric fluid.Its comportment in chlorine gas is very similar requiring also however the aid of heat; mixed with minium and heated it burns with such an intense evolu- tion of caloric that the mass is thrown out with a report. Titanium possesses the property of decomposing water ;at the temperature of loooC. (ZIZo F.) in pure water hydrogen gas begins to be evolved and in warm hydrochloric acid it is dissolved with a brisk disengage- ment of hydrogen. Ammonia throws down from the solution a black oxide; if the liquid be then warmed a disengagement of hydrogen takes place the precipitate becomes first blue and is after- wards transformed into white titanic acid. The Author has the intention of extending his experiments on the compounds of nitrogen to the other substances nearly allied to tita- nium namely to silicium and boron in the hope of increasing our knowledge respecting the nitrides of the metals for the discovery of which we have to thank Schroetter and also in the hope of obtaining something definite from the compounds discovered by Balmain.

ISSN:1743-6893    

DOI:10.1039/QJ8500200352

出版商:RSC    

年代:1850

数据来源: RSC

摘要:

NOTICES OF PAPERS CONTAINED IN THE FOREIGN JOURNALS. On the isomeric mod@cations of phosphoric acid.*-Rose has shewn that the oxides of tin and the other metallic oxides which possess an acid cha- racter are capable of assuming very different properties when exposed to different degrees of temperature but phosphoric acid far surpasses any of these metallic acids in the paradoxical isomeric modifications which it undergoes. 1 Metaphosphoric acid.-The metaphosphoric acid of Graham exists in no less than three isomeric modifications the one of which is that originally described by its discoverer and is prepared in combination with soda by melting and allowing to cool slowly the acid phosphate of soda or micro- cosmic salt. The solution of this salt is neutral or very slightly acid and is characterized more particularly by producing precipitates with neutral solutions of many salts of the earths and metallic oxides which are generally soluble in an excess of the soda salt and possess the remark- able property of conglomerating when shaken into a heavy thick oily mass.The solution of the salt itself affords no precipitate with a diluted and filtered solution of white of egg but a precipitate is immediately formed in the mixture on the addition of acetic acid. The properties of this solu- tion with reference to other salts have been carefully investigated by Rose who finds that the acid separated from the soda salt by pre- cipitation with silver and subsequent treatment of the silver salt with sdphuretted hydrogen differs in some respects from the metaphosphoric acid obtained by burning phosphorus in oxygen gas.The acid separated from the soda salt produces no immediate precipi- tate in chloride of barium a flocculent sediment being deposited only after the expiration of some time baryta water on the other hand even when not in excess and the liquid is still acid produces a precipitate directly. With the metaphosphoric acid obtained by the combustion of phosphorus an immediate copious precipitate is produced by chloride of barium which requires a large excess of the acid to dissolve it. * Pogg. Ann. LXXVI. 1. NOTICES OF FOREIGN PAPERS. The oily resinous precipitate produced by the acid of Graham’s salt in nitrate of silver has been analysed by Weber and found to contain quan- tities corresponding to the formula 3 Ago 2 PO + HO.This composi- tion accounts in some measure for the acid obtained from the salt possessing different properties from that produced directly from phosphorus. When however the silver precipitate is separated at once from the liquid and dried between blotting paper its composition then corresponds to that of the soda salt. 2. The second modification of metaphosphoric acid is that contained in the singular class of salts prepared by Fleitmann and Henneberg by cooling very slowly melted microcosmic salt. The salt of soda thus prepared has precisely the same composition as Graham’s salt but differs from it in being opaque and of a crystalline structure while the latter is transpa- rent and amorphous.It crystallizes from solution with four atoms of water and the solution like that of Graham’s salt has a neutral re-action. The most remarkable property of this modification of the acid is that of producing soluble compounds with all bases and this enables it to be easily distinguished from all others. 3. The acid in the salts formerly known as acid phosphates which are insoluble in water and in acids may be viewed as the third submodifica- tion of metaphosphoric acid. These salts are obtained by the fusion of salts with phosphoric acid until a portion of the fused mass precipitates a solution of white of egg. All these modifications of the acid have the same capacity of satura- tion ; they all precipitate a solution of albumen which is an excellent qualitative test for a metaphosphate; it is necessary however to add acetic acid to the soluble salts in order to effect this precipitation.The property of precipitating chloride of barium is peculiar to that modification of the acid which is produced by the combustion of phos- phorus. When ordinary phosphoric acid is heated for several hours without volatilization occurring the modification well known as pyrophosphoric acid is obtained ; if however the heat be continued until the acid begins to volatilize the product then affords a copious precipitate with albumen and chloride of barium ; nitrate of silver is also precipitated white which precipitate becomes resinous when agitated this proves that meta-phosphoric acid has been produced.Uncertainty still reigns respecting the true composition of melted phosphoric acid. Rose found in three experiments in which the acid was successively heated to higher tempera- tures that the amount of water contained in the product was less each time than is required by the formula PO + HO. This result appears to indicate that by constantly applied heat the whole of the water might be removed and anhydrous phosphoric acid obtained. Rose is inclined to explain the various properties of metaphosphoric 358 NOTICES acid by msuming that it is a conjugate acid. The conjunct he states might be anhydrous phosphoric acid associated in varying proportions with pyrophosphoric or ordinary phosphoric acid and it may be this conjunct or the anhydrous acid which possesses the property of precipi-tating albumen and communicates this property to all the modifications of metaphosphoric acid.2. Pyrophosphoric acid.-This modification of phosphoric acid requires the assumption of at least two sub-modifications to explain the different characters of its salts. The one acid is contained in the salt obtained by heating ordinary phosphate of soda to redness and in the salts derived from it. The other is produced in a similar manner to the insoluble metaphosphates of Maddrell when salts containing an excess of phospho-ric acid are heated to a temperature somewhat lower than that which is required to convert them into metaphosphates. By this processs a copper salt at least is produced by treating nitrate of copper with phosphoric acid which is quite as insoluble as metaphosphate of copper.The acid of this salt is however easily eliminated by sulphuretted hydrogen and has in the aqueous solution the same properties as ordinary pyrophos- phoric acid. Rose accounts for the different properties and saturating powers of pyrophosphoric and ordinary phosphoric acids by the isome- rism of the two acids and considers it not improbable that the one atom of water in ordinary phosphate of soda might be expelled without con- verting the salt into a pyrophosphate. Experiments undertaken with this object in view have not however proved successfiil Pyrophosphoric acid has a strong tendency to form double salts as has been pointed out by Stromeyer and more recently by Persoz and Baer has lately made the interesting observation that the precipitates produced by a solution of pyrophosphate of soda which are insoluble in an excess of the precipitant are often insoluble double salts of the soda salt with the pyrophosphate produced in which the soda and the other base can mutually replace each other without both as it appears being contained in the double salt in a definite simple relation.Even the silver salt con-tains small portions of soda. Rose describes the reactions of the pyrophosphates and of the isolated acid with great minuteness and establishes the fact in contradiction to the statements of Berzelius that pyrophosphoric acid does not precipitate albumen and that this is the chief and most characteristic mode of dis-tinguishing this acid from metaphosphoric acid.3. Ordinary phosphoric acid.-Rose calls attention to one property of the salts of this acid which appears to have been overlooked and which is very characteristic of them it is the solubility of very many insoluble phosphates in an excess of the saline solution from which they have been precipitated by phosphate of soda. This solution generally possesses the property of affording a copious precipitate when heated which disappears on cooling. Double salts are therefore produced which are decomposed OF FOREIGN PAPERS. by a high temperature. Precipitates produced by a pyrophosphate are also often soluble in an excess of the saline solution ; these solutions when heated also become turbid but the turbidity is permanent even when the solution cools.The reactions of phosphate of soda with the whole series of metallic salts have been again minutely investigated in the paper before us ; for the detail of these experiments we must refer to the original. One excel- lent test for the presence of phosphoric acid recently proposed by Svan- berg and Struve claims however particular attention this is molybdate of ammonia. The test is so delicate that the most minute traces of the acid are detected by it under circumstances when other tests are imp- plicable. If a solution of molybdate of ammonia is added to any solution of a phosphate and then a sufficient quantity of hydrochloric or better of nitric acid to dissolve the precipitate which is at first formed the liquid immediately becomes coloured yellow and deposits a yellow precipitate of molybdic acid which however is not the ordinary modification of the acid and is only produced in the presence of phosphoric acid.If the phosphate for examination is insoluble in water a solution in nitric acid may be employed for this test. Heat accelerates the precipi- tation. The yellow precipitate is soluble in ammonia as well as in an excess of the phosphate. For this reason the test is peculiarly applicable for detecting small quantities of phosphoric acid and larger quantities of phosphate are liable to elude detection from the great amount of molyb-date required to produce the yellow precipitate after supersaturating by means of nitric acid.The colour of the solution does not interfere with the distinct recogni-tion of the characteristic colour of the precipitate. It is only the salts of ordinary phosphoric acid which are subject to this reaction the other modifications must be brought into that state therefore before the test can be applied. On a series of insoluble alkaline salts of phosphoric and arsenic acids.*-The only known double salt of phosphoric acid with an earth and an alkali which is insoluble in water is the phosphate of ammonia and mag- nesia and this contains two atoms of magnesia to one of ammonia. Rose however has discovered that similar double salts of potash and soda as well as of lithia can be produced both with magnesia and with lime.The circumstances under which these salts are most readily pre- pared are When an atom of pyrophosphate of the earth is intimately mixed with an atom of carbonated alkali and the mixture heated to redness until it * Pogg. Ann. LXXVII. 288. 360 NOTICES suffers no further loss of weight. The mass in this operation is not melted nor even agglutinated. It is then heated with water for some time and washed with hot water. It is requisite that these proportions be adhered to in order to secure the formation of a considerable portion of the salts. The compounds obtained yielded with few exceptions due to subse-quent decomposition results on analysis which indicated very closely two atoms of the earth to one of alkali and one of phosphoric acid.The washing process requires some time but the alkali may often be entirely removed if it be too often repeated and its place in the compound is then filled by water. The following compounds have been obtained in this manner and were arialysed by M. Weber. Phosphate of potash and lime phosphate of soda and lime phosphate of potash and strontian phosphate of soda and strontian the composition of this however approached nearer to the formula 2 (NaO 2 StO PO,) + HO 2 StO PO . phosphate of potash and ba yta. The phosphates of potash and baryta and of soda and ba yta did not agree closely with the formula Phosphate of potash and magnesia. Phosphate of soda and magnesia. Phosphate of lithia and lime. Chlorides of the alkalies yield the same salts when fused with phos- phates of the earths.If however phosphates of the earths are contained in acid solutions in common with the alkalies the former can then be precipitated by ammonia and the precipitate contains no alkali. The compounds described above are therefore not produced in the bumid way although the total amount of the phosphate is not precipitated in consequence of the presence of the ammoniacal salt that is produced. Other double salts which are soluble and contain two atoms of alkali to one of an earth and one of phosphoric acid appear also to be formed under certain circumstances. When an organic substance is charred and the charred mass is extracted with water the aqueous solution frequently contains phosphates of the earths particularly phosphate of lime which are separated by evapora- tion to dryness and treatment of the dry residue with water.The pyrophosphates of the earths have in this case been dissolved by phos- phates of the alkalies with which they form double salts. When an excess of pyrophosphate of soda is heated to incipient redness with carbonate of lime the aqueous solution of the fused mass contains phosphate of lime. In performing this experiment two atoms of ppo-phosphate of soda should be employed to one atom of carbonate of lime. The lime is detected in the solution by oxalic acid. The phosphate of lime is not easily separated by evaporating the solution to dryness or by passing carbonic acid through it but readily when carbonate of soda is OF FOREIGN PAPERS.361 added the whole being then evaporated to dryness. The phosphate of lime thus precipitated contains when washed no carbonate of lime. A double salt has obviously been foimed in this case of phosphate of soda and phosphate of lime ; the latter separates when a portion of the soda in the solution is converted into carbonate of soda. The arseniates of the earths are even more completely decomposed by fusion with carbonates of the alkalies than the phosphates. The double compounds formed were those of potash and soda with magnesia and arsenic acid ; they are easily decomposed however by water that sub-stance in part replacing the alkali. On the products of the distillation pf lactic acid and of lactate of copper by Engrlhardt.*-When highly coiicentrated lactic acid is exposed in a retort to a temperature of from 130-1 40' (2980 to 3 1 60 F.) an acid watery liquid distils over possessing a somewhat empyreumatic odour.This liquid is dilute lactic acid. If the temperature be kept up in the retort until no more water passes off a residue is obtained which is amorphous of a brown red colour melts at a temperature below the boiling point of water possesses a very bitter taste and is soluble in alcohol this residue consists of anhydrous lactic acid (Clz H, O1J. This acid is very slightly soluble in hot water and is deposited almost entirely when the water cools-it is precipitated from alcohol by water. Boiled with water for a length of time or exposed for a long period to a moist atmosphere the anhydrous acid is again converted into the ordinary modification.This transformation is more speedily effected by the alkalies and alkaline earths. Heated above 250' (482' F.) anhydrous lactic acid evolves car-bonic oxide gas which towards the end of the operation if the tempera- ture has not risen above 260" (500' F.) is mixed with only 3 to 4 volumes per cent of carbonic acid. During this process of distillation a yellow liquid condenses in the cooled receiver which either deposits crystals or solidifies into a crystalline magma a small quantity of a light porous charcoal remaining in the retort The condensed product was found to be a mixture of aldehyde lactide citraconic and hydrated lactic acids. Lactone and acetone which had been previously found in the distillate by Pelowe were not obtained by Engelhardt.The other products appear to result from the decomposition of lactide which the author was unable to obtain from anhydrous lactic acid without a partial decomposition. In one experiment in which 19.5 grms. of anhydrous lactic acid were decomposed at a temperature of 260" (5000 F.) and which operation lasted * Ann. der Chem. u. Pharm. LXX. 241. VOL 11.-NO. vrrr. BB 362 NOTICES eight hours 12.2 per cent of aldehyde and 14.9 per cent of lactide were obtained while 1 per cent of charcoal remained in the retort. At a higher temperature e. g. 300* C. (572O F.) the evolution of gas is much more copious and the quantity of aldehyde is increased the lactide being then decomposed into aldehyde and carbonic oxide as is shown by the following formule 1 eq.Aldehyde . 2 ),Carbonic oxide . 1 ),Lactide . * c H 0 The products of decomposition of anhydrous lactate of copper vary likewise with the temperature employed. Between 200 and 2iOo (2920 and 4100 F.)carbonic acid is evolved and aldehyde with some hydrated lactic acid collected in the receiver (the latter being probably due to some water of crystallization in the lactate). The oxygen in the oxide of copper has here evidently converted the carbonic oxide into carbonic acid. The evo- lution which was copious at a temperature of 2103 ( 410' F.) gradually ceases and metallic copper and anhydrous lactic acid remain in the retort which latter is decomposed when the temperature has risen to 250 or 260° (462" to 500' F.).The author recommends the preparation of aldehyde from the lactates containins a weak base. The decomposition of the lactates containing strong bases gives rise to very different products an account of which is reserved for a future occasion. AZZantcin:in:the urine of the calf.*-It is well known that the allantoic fluid of the cow contains a peculiar body allantoin. This fluid is also known to be the urine of the fcetus. Wohler suspected and has proved that the urine of the living newly-born calf also contains this substance as a constant and physiologically essential ingredient. The urine of the calf may be employed as a source of allantoin several grammes of which being contained in or procurable from a single well filled bladder.The urine is evaporated to the consistence of a thin syrup without being allowed to boil and is then left standing for several days when allantoin crystallizes from it mixed with much phosphate of magnesia and an amorphous gelatinous body consisting chiefly of urate of magnesia. The urine is diluted with water and poured off with the gelatinous matter from the crystals. These are then washed once or twice with cold water and heated with water to the boiling point when they dissolve leaving the insoluble phosphate of magnesia. The solution is rendered colourless by animal charcoal. The hot filtered solution should then be acidulated * Ann. der Chem. und Pharm. LXX. 229. OF FOREIQN PAPERS.with a few drops of hydrochloric acid to prevent the precipitation of a little phosphate of magnesia which may have dissolved allantoin then crystallizes perfectly colourless from the cold liquid. The crystalline form of allantoin prepared by the foregoing method is always different from that obtained from the allantoic fluid and from uric acid however often it may have been recrystallized. The crystals are thinner and grow together in bundles while those from the latter sources are well defined qarticularly at their terminations. This modification of form appears to arise from a very slight admixture of some foreign sub- stance which is in too minute quantity seiisibly to affect the composition of the allantoin and which is perfectly separated by combining it with silver and subsequently decomposing the silver compound by hydrochloric acid.On the composition of Stewin by G. Arzbacher.*-The discordant results obtained by different analysts with reference to the composition of stearin (see Gmelin Handbuch Bd. IV. Seite 200) induced the author to rein- vestigate the composition of this fat. The results of his investigation prove that the stearin of ox suet and mutton suet are two distinct com- pounds. The analysis of Chevreul and Lecanu having reference to that from the ox while those of Liebig and Pelouze apply to the fat of the sheep. The mean of four analyses of stearine from three different sources yielded the following results Carbon. Hydrogen. Oxygen. Stearin from ox suet .. 78.74 12-27 8.99 Stearin from mutton suet . . 76-50 12.28 11.22 The former would therefore consist of 1 atom of glycerin + 2 atoms of stearic acid- 8 atoms of water while the latter is composed of 1 atom glycerin + 2 atoms of stearic acid -4 atoms of water. Their formulze being respectively Stearin of the ox Cia Hi, 0 ,> ,? sheep . G42 H, 016 100 parts would therefore yield by saponification Ox tallow. Mutton tallow. Stearic acid . . 98.15 94.90 Glycerin . . 8.50 8-23 106.65 103.13 * Ann. der Chem. und Pharm. LXX. 239. 364 NOTICES Experiments with albumen casein and$brin by F. Bopp.*-Albumen ca-sein and fibrin were exposed by the author to the same chemical agents with a view to ascertain whether the products were the same in the case of each.Acids strong alkali and putrefaction. gave rise in every case to the formation of leucin ; alkali and putrefaction agrtin destroyed this product when their action was prolonged for a sufficient length of time giving rise to a large quantity of valerianie acid. Acids and alkali give rise to the formation of tyrosin ; the alkali if allowed to exert its influence sufficiently long again decomposes this substance. Putrefaction however which extends its influence beyond the stage at which leucin is produced stops short before the formation of tyrosin is effected. Besides the well characterized substances leucin and tyrosin another crystallizable subshnce was obtained by the action of acids but was not more minutely examined by the author.In like manner a volatile cry- stalline body was observed as resulting from the putrefactive process characterized by a penetrating oclour and an oily acid but slightly soluble in cold but more soluble in hot water the lead salt of which is resinous and soluble in alcohol. Leucin is the first product of the action of hydrate of potash on any of these bodies ; tyrosin is an after-product. The acid therefore is the producer of the tyrosin and carries on a similar action to a greater extent than the process of putrefaction giving rise however at the same time to a smeary nitrogenous substance which was not observed as the result of the putrefactive process. The action of the acids is not attended by the evolution of any gases while putrefaction gives rise to abundance of carbonic acid sulphuretted hydrogen and water which are the simplest constituents or proximate principles of these complex groups of atoms.Nitrogen appears in five different products of these decompositions in ammonia leucin tyrosin ; a substance similar to these two latter observed in small quantity and in the volatile body SO characteristic by its intense odour. The sulphur of these protein compounds is evolved as sulphu-retted hydrogen when putrefaction or alkali are the destructive agents ; when acids are employed to effect the decomposition it remains in corn-bination with a brown amorphous mass not yet further investigated. On the chemical composition of bones.j-The composition of the phos- phate of lime contained in bones has generally been assumed upon the authority of Berzelius to be represented by the formula 8 CaO 3 PO,.Some chemists however e. g. Marchand and Boussingault have * Annalen der Chem. u. Pharm. LXIX. 16. .t. Pogg. Ann. LXXVII 267. OF FOREIQN PAPERS. expressed an opinion that the true composition of this compound should be expressed by the formula 3 CaO PO,. With a view to clear up these contradictory statements Heintz has most thoroughly reinvestigated the entire composition of the bones of man of the ox and sheep. The following tabular statement contains the numerical results of his analyses. Of the two analyses of human bone the first was executed with bone which had been charred while for the second the inorganic constituents were extracted from the dried bone by muriatic acid in order to avoid any possibility of error which might possibly have arisen from a loss in phos- phoric acid in the process of charring.The two experiments prove that the temperature employed in the case of the first was not sufficiently high to cause any decomposition of the phosphates. The carbonic acid has been calculated as in combination with lime and the magnesia as in combination with phosphoric acid. ox. Sheep. Man. -I-IT. Carbonate oflime . . 7.07 7*00 6.36 6-39 Phosphate of magnesia (3 CaO PO,) . . . 2-09 1-59 1.23 1.21 Phosphate of lime (3 CaO PO,) . . . . .58.30 62-70 60.13 59.67 Lime . . . . . . 1.96 2.17 1.81 1-62 Organic matter &c. .30.58 26.54 30.47 31.11 -___.-100 100 100 100 The excess of lime indicated by these analyses was found by direct expe- riment to he in combination with fluorine.The composition of bones therefore irrespective of the organic matter would be Ox bone. Sheep bone. Human bone. -I. 11. Carbonate of lime . . 10.07 9.42 9.06 9-19 Phosphate of magnesia (3Mg0 PO,) . . . 2.98 2-15 1.75 2-74 Phosphate of lime (3CaO PO,). . . . . . 83.07 84.39 85.62 85.83 Fluoride of calcium . . 3.88 4.05 3.57 3-24 100~00 100~00 100*00 100~00 NOTICES OF FOREIGN PAPERS. These experiments therefore prove 1. That the bones of the vertebrate animals contain a small amount of fluoride of ealcium as has been already shewn by Berzelius Frerichs Erdmann and others.2. That the chief rnass of the bones which communicates solidity to their structure is entirely free from chlorides from sulphates and from iron. Wherever these have been found as constituents of bone the fluids con-tained in the bone had not been previously removed by water. 3. That the amount of fixed bases in bones is exactly sufficient to satu- rate the acids associated nith them and consequently not only the phos- phate of magnesia which is only difficnltly soluble when it contains three atoms of base to one of acid and in which state it can only be contained in bone that has beeii treated nit11 water biit also the phosphate of lime must be contained in such proportion as to correspond to the formula 3R0,PO,.

ISSN:1743-6893    

DOI:10.1039/QJ8500200356

出版商:RSC    

年代:1850

数据来源: RSC