BY JAMES M. PETRIE. 109 



was distilled, and the remaining aqueous solution diluted 

 with water to a definite volume. 



(2) The solution tested hy protein-reagents: — 



Millon's reagent, — -very faint positive reaction after 



boiling. 

 Heller's nitric acid test, — nil. 



Xanthoproteic, boiling nitric, then ammonia, — ex- 

 ceedingly faint yellow. 

 Ehrlich's diazo-reaction, — doubtful, perhaps slightly 



positive reaction. 

 Biuret test, — negative. 

 Salicyl sulphonic acid — negative. 

 Salicyl sulphonic acid — in filtrate after saturation with 



ammonium sulphate,— no ppt. 

 Lead acetate — no ppt. 

 Phosphotungstic acid, — large white ppt. 

 Mercuric nitrate — bulky white ppt. 

 The solution is, therefore, practically protein-free, and the 

 reactions of Millon's and Ehrlich's solutions show that only 

 a trace, if any, of tyrosin or histidin can be present. A large 

 amount of basic substances is indicated by the precipitate 

 with the alkaloidal reagent phosphotungstic acid ; and this 

 may, of course, include certain lesser polypeptides which do 

 not contain a biuret reacting group. 



(3) The distribution of the nitrogen. — A solution of the 

 non-protein nitrogen compounds was prepared by method (a), 

 and examined in the following manner : — 



(i.) The total amount of nitrogen was ascertained. 



(ii.) A portion was set aside under a bell-jar with milk of 

 lime, for the Schlbsing estimation of ammonia ; while another 

 portion was distilled with magnesia in a current of steam, 

 and the ammonia collected in decinormal acid. The Schlbs- 

 ing method gave small and variable results, and was dis- 

 carded. When the solution is boiled with magnesia, a very 



