CONSTITUTION OF GLYOOCOLL AND ITS DERIVATIVES. 9]^ 



R.CH-NO., R.CH-NH2 

 CO.ÜH CO.OH . 



" Amido-acids " are. however, not produced in these reactions ; it is 

 their hydrochlorides, 



K.CH-NH3CJ 



I 

 CO.OH 



which are actually obtained. In order to prepare the " amido-acid " 

 itself, giycocoll for example, the hydrochloride is digested with silver 

 oxide (or litharge), and the silver-glycocoU decomposed by sulphuret- 

 ted hydrogen. The changes which occur in these operations are in 

 accordance with the following scheme : 



*ö 



H.C-NH.Cl HoC-NAgH.,Cl^ H.C-NAgH., 



I +Ag,0- I FTOj1= I I +AgCl. 



OC-OH 00-OAg OC-0 



H.,C-NAgH, HX-NH3 



2 .| I ^ +H,8 = 1> I I + Ag.S . 

 OC-0 OC-0 



It may be thouglit, however, that the separation of silver chloride 

 occurs, not in the manner indicated above, but as follows : 



H.,C-NAgH.,Cl H.,C-NH., 



I = I + AgCl. 



OC-OAo- OC-OAg 



Against this objection, it may be pointed out that the properties of 

 silver-glycocolJ cannot, as will be shown later on, be accounted for by 

 regarding it as an amido-acetate, but that all its reactions are most 

 satisfactorily explained by the formula, 



