CONSTITUTION OF GLYCOCOLL AND ITS DERIVATIVES. 99 



Turaing" now to the silver derivative, the metal himmonium theory 

 ofives it the constitution, 



H.,C-NH.Ao- 

 OC - ; 



and although the formation of amido-acetic esters by the action of 

 alkyl iodides upon it is brought forward against this view (Kraut ; 

 op. cit., 310), I see no ground whatever for this ai'gument. Repre- 

 .senting, as is usually done, the action of alkyl iodides upon silver- 

 gl vcocoll, as if direct replacement of silver by alkyl radicals took place, 



H,C-NH,;Ag+IiR 



"I I "'" ■■ 



OC-0 



the formation of amido-acetic esters, HoX.CHo.COOR, would, indeed, 

 oifer a difficulty to the metallammonium theory ; but the action in 

 this case, as in other analogous cases, must be regarded as primarily 

 of an additi\'e nature, the unstable addition compound, then, decom- 

 posing into silver iodide and the ester, under the conditions of the 

 experiment : 



H.C-NH.Ao- HoC-NH.,AoI IIX-NH. 



II ^ + IR = I -- I + Agi . 



OC-0 OC-OR OC-OR 



The formation of amido-acetic esters, and not alkyl-glycocolls, bv the 

 action of alkyl iodides upon silver-glycocoll is a strong argument 

 against the metallamitlo-acelic acid thcurij (MHX.CtL,.COOH), but it 

 does not t(3uch the metallammonium theory. 



The formation of hippuric acid by the action of benzoyl chloride 

 upon silver ((jr zinc) giycocoll is, on the other hand, a death-blow^ to 



