98 



J. SAKUEAI. 



co!)per Compound which they represent by the forniulu, COOR.CHg. 

 NH — Cu — XH.CHo.COOK ; whilst Kraut denies the existence of such a 

 compound and shows, by a careful experimental study, that the inter- 

 acticjn between the hydivjchloride of an amido-acetic ester and cupric 

 oxide occurs ac('ording to the ecjuation : 



H.,C-NH3C1 H.,C-NH, H,X-CH, 



2 "I +CuO= 'I I +Cua + 2R0H. 



OC-OR OC-0 — Cu — 0-CO 



Kraut concludes from tliis that it is the hydrogen of the hydroxyl, 

 not that of tlie amidogen, which is replaced by copper. 



It must be observed, however, that w^hat Kraut obtained is a 

 double copper compound, having the composition, CuCl2.(H2^^.CH2. 

 COO),,Cu, or more simply, as he himself puts it, HäN.CHo.COOCuCl; 

 but he does not give any explanation of the formation of this double 

 salt in support of his views. I think a satisfiictory explanation of the 

 formation and existence of this double salt can be readily obtained by 

 supposing that cupric oxide displaces an equivalent of an alcoliol 

 from the hydrochloride of an amido-acetic ester, according to the 

 equation, 



H.C-NH3CI H.C-NH^Cl 



oi-OR '"'"''^ oi^_o>Cu + ROH, 



H.C-NH3CI H^C-NH.Cl-Cu-CJH.N-CH^ 



or, 2 "1 +2CuO- I I +2R0H. 



OC-OR OC-0 Cu 0-CO 



The view here advanced as to the constitution of the copper compound 

 obtained by Kraut is in perfect harmony with his experimental data ; 

 at the same time, it shows that his conclusion that copper must be 

 wholly carboxylated is groundless. 



