CONSTITUTION OF GLYCOCOLL AND ITS DERIVATIVES. ^Q]^ 



op. cit, 299). Horsford (Lieh. Ann., 60, 33 [1846]) and, more recent- 

 ly, Cartius (J. prali. Clinn., 26, 159 [1S,S2]) attempted in vain to 

 prepare these bodies in the pure state; it is only by mixino- concent- 

 rated acpieons solutions of ^-lycocoll and an alkaline earth, pourino- 

 the mixture into alcohol, and leaving- the precipitated oil for some 

 days in contact with the mother hquor that Kraut was able to obtain 

 them in a pure and crystalline condition. The evident difficulties, 

 under which these bodies are formed, mark them off from ordinary 

 carbox3dic salts, a circumstance which shows that they are probably 

 also metallammonium compounds. The comparative ease wdth which 

 derivatives containing copper, silver, mercur3^ &<•. are formed and 

 the difficulties, which attend the preparation of those contai ning the 

 metals of the alkaline earths, and which increase still more in the case 

 of those containing alkali metals (these derivatiA^es, in fact, do not 

 seem to htive been isolated as yet), sj^eak again in fovour of the metall- 

 ammonium theory; inasmuch as metals like copper, silver, and mer- 

 cury are eminently characterised l)y the ease with wdiich they form 

 ammoniated derivatives. In opposition to Kraut's words, " Ich halte 

 daher sämmtliche Metallverl^indungen des G^lycocoUs für wahre amido- 

 essigsaure Salz," I would rather say that all metalJic derivatives of 

 (flijcocoU are metaUammonium compounds. 



The above examination of the modes of formation and trans- 

 fcn-mation of glycocoll irresistablv leads to the internal ammonium 

 theory of its constitution; there is, however, one other ])oint which 

 must be considered before going further. Tlie point in question is 

 the relation l)etween glycocoll and the so-called diglycolamidic and 

 triglycolamidic acids. The latter coinpounds are usually represented 

 by HX(CH,.COOH), and X(rH2.G00H), respectively, and glycocoll 

 and these two bodies are compared to mono-, di-. and triethylamine; 

 this relation is even regarded as an argument for the open formula for 



