Action of Sulphuric Acid upon Anisic and Salicylic Acids. 143 



myself, by a series of careful experiments, that this assertion is with- 

 out the slightest foundation. 



Thialdine, when treated with oxide of silver, as might have been 

 expected, undergoes the same decomposition which Liebig and 

 Wcihler had effected by means of nitrate of silver. It furnishes in 

 this process aldehyde, acetic acid, and ammonia, but no leucine. 



In conclusion, a remark which refers to a question connected with 

 this alleged formation of leucine : — Soon after the statement regard- 

 ing this subject had been made, Wagner* observed that the action of 

 bisulphide of carbon upon amylamine gives rise to the formation 

 of a crystalline compound. This compound was not analysed, but 

 Wagner suggested that possibly it might be thialdine, 



CioHi3N + 2CS2=Ci2H,3NS„ 

 Amylamine. Thialdine. 



and that in case this assumption proved to be correct, the action 

 of bisulphide of carbon upon the homologues of ammonia might 

 lead to the artificial formation, not only of leucine, but of glycocine, 

 alanine, &c. 



During my experiments on the deportment of bisulphide of 

 carbon with organic bases, I have also had occasion to study the 

 compound of amylamine with bisulphide of carbon. It is only 

 necessary superficially to compare this substance with thialdine, 

 in order to perceive at once that they are two absolutely different 

 compounds ; and if there is still a chance of producing leucine from 

 amylamine, it is because the action of bisulphide of carbon does 

 not give rise to the formation of thialdine. 



"On the Action of Sulphuric Acid upon Anisic and Salicylic 

 Acids." By A. W. Hofmann, LL.D., F.R.S. 



In a paper read before the Royal Society f, we have, Mr. Buckton 

 and myself, directed attention to the general occurrence of the 

 disulpho-acids, of which only few and scattered examples were known 

 at that time. 



M. Louis Zervas has since continued the study of this subject 

 in my laboratory, and has arrived at the following results. 



Anisic acid, treated with Nordhausen sulphuric acid, at a tem- 

 perature of 100'^, assimilates the elements of 2 equivs. of sulphuric 

 acid, and is converted into a crystalline acid, containing 

 Ci, Hg 0„ + 2HS0,= C,« Hg S^ O,^ + 2aq. 



The formula of this acid, which M. Zervas calls sulphanisic acid, 

 was controlled by the analysis of a crystalline lead-salt and a barium 

 compound, which were found to contain respectively 

 Lead-salt .... Ci^ (11^ Pb^) O,^ + 2aq. 

 Barium-salt . . Cj^; (II^Ba,,) Oj2 + 2aq. 



If the mixture of anisic and fuming sulphuric acid be submitted 

 to higher temperatures than that of boiling-water, a lively evolution 

 of carbonic acid takes place, containing, if the temperature be main- 



* Journal fiir Praktisclie Chemic, Ixi. ."iOS. 

 t See Phil. Mag. vol. xiii. p. 270. 



