i66 Proceedings Columbia Biochemical Association [Sept. 



to black Solution, from which free alkali and free silver can be 

 removed by dialysis. The neutral Solution thus prepared appears 

 to contain argent-ammonium-mucoid, which may be obtained by 

 precipitation with alcohol or by direct desiccation. The aqueous 

 Solutions of these products are similar to those of argyrol in many 

 respects yet appear to keep indefinitely. The purified material is 

 antiseptic, and retards the growth of plants, but is seemingly non- 

 irritant to the Cornea or other animal tissues. Fairly large quan- 

 tities fail to induce toxic effects when injected subcutaneously or 

 intravenously into dogs. The product in aqueous Solution is decom- 

 posed by acidification. The purified material yields about i6 per 

 cent. of ash. The silver content will be given special attention in the 

 near future. 



i6. Protein-copper products. Sidney Born. Concentrated 

 aqueous Solutions of various indiffusible proteins, when rendered 

 slightly alkalin with sodium hydroxid Solution and treated with a 

 moderate quantity of copper sulfate Solution, exhibit the typical 

 biuret reaction in marked degree, but the excesses of alkali and 

 copper may be removed by dialysis and, as the process continues 

 (although no color may appear in the diffusate), the deep "biuret 

 color" slowly changes until finally a blue or green persists. The 

 resultant protein-copper product was isolated by precipitation of 

 such a Solution with alcohol or by its direct desiccation. The Pro- 

 portion of copper in six products made from edestin, gelatin, and 

 serum protein ranged from 4.2 to 6.3 per cent. Injected subcuta- 

 neously into frogs, the edestin and gelatin products (1.3 c.c. of 

 concentrated aqueous Solution in each case) caused death in three 

 hours. The properties of the dialyzed Solutions and the products 

 therefrom will be described in some detail later. 



17. A biochemical study of the phenomena known as com- 

 plement Splitting. J. J. Bronfenbrenner and Hideyo Nogu- 

 CHi.^^ A. It is generally accepted that complement may be split 

 into a mid-piece and an end-piece. The mid-piece is thought to be 

 in the globulin fraction, and the end-piece in the albumin fraction. 



11 



Bronfenbrenner: Dissertation, Columbia, 1912; Bronfenbrenner and 

 Noguchi : Journal of Experimental Mediane, 1912, xv, 598-643. Most of the 

 work was conducted at the Rockefeller Institute for Medical Research. 



