1863.] 383 



I have fixed the composition of dimethylamine by the analysis of 

 the platinum-salt and gold-salt. The former is one of the finest salts 

 which I have ever examined, crystallizing in long splendid needles, 

 shooting through the liquid from one side of the vessel to the other. 

 It contains 



C 2 H 8 N Pt C1 3 = [(C H 3 ) 2 H 2 N] Cl> Pt C1 2 . 



The gold-salt, which likewise crystallizes very well, has an analo- 

 gous composition, viz. 



C 2 H 8 N Au C1 4 = [(CH 8 ) a H 2 N] Cl, Au C1 3 . 



If the products obtained by distilling the sulphite of aldehyde- 

 ammonia with lime had contained the minutest trace of dimethyl- 

 amine, the formation of the beautiful characteristic platinum-salt 

 would have revealed it. In none of the experiments did I observe 

 the formation of this compound. 



III. " Contributions towards the History of the Monamines. 

 No. VII. Transformation of Aniline into Benzoic Acid." 

 By A. W. HOFMANN, LL.D., F.R.S. Received December 

 3, 1862. 



In a Note recently addressed to the Royal Society, I have described 

 a new organic base which is formed of a secondary product in the 

 manufacture of aniline upon a large scale. This substance, paraniline, 



C 12 H U N 2 , 



is isomeric with aniline, and owes its origin evidently to the action of 

 heat, under circumstances not yet precisely determined, upon that 

 body. I have not yet succeeded in producing this compound from 

 aniline, but the experiments made with the view of accomplishing 

 this transformation have led me to an observation which I beg leave 

 to mention briefly to the Royal Society. The vapour of aniline, 

 when passed through a red-hot glass tube, undergoes decomposition ; 

 the tube becomes coated with a film of carbon, a brown liquid collects 

 hi the receiver, and a colourless gas burning with a luminous flame 

 is evolved ; if this be allowed to pass through water, the latter becomes 

 charged with a considerable amount of cyanide of ammonium. 



