493 



the experiment, it was found that the liquid contained considerable 

 quantities of ammonia, but together with the latter alkali a fixed 

 base. This unexpected deportment reminded me of experiments 

 published several years ago *, on the action of oxide of silver on 

 thialdine, which is said to be thus converted into Leucine. The 

 question presented itself, were the phenomena observed in the pre- 

 sent case of an analogous character ? had the above experiment given 

 rise to the formation of methylated Leucine 1 



Experiment proved that the decomposition of iodide of methyl- 

 thialdine by oxide of silver gives rise to the formation of ammonia 

 and of the oxide of tetramethylammonium 



NO, HO, 



which was satisfactorily identified by the analysis of the gold- and 

 platinum-compound. 



The following equation represents this change : 



4C 14 H 16 NS 4 I + 20AgO + 2HO=4AgI+16AgS+12C 4 H 4 O 2 



Iodide of methyl- Aldehyde, 



thialdine. +3H,N + 



Hydrate of the oxide of 

 tetramethylammonium. 



The absence of any leucine-like compound among the products of 

 decomposition of iodide of methyl thialdine induced me to repeat the 

 experiment on the action of oxide of silver upon thialdine itself. 



The transformation of thialdine into leucine, announced several 

 years ago, and apparently very intelligible by the analogy of the 

 formulae of the two bodies 



Thialdine C 12 H 13 NS 4 



Leucine C 12 Hi 3 NO 4 , 



has not failed to rivet the attention of chemists. I wonder how 

 such an error could have crept into science ; for I have convinced 

 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 



* Goessmann, Liebig's Annalen, xc. 184. 



2 o2 



