EXPERIMENTAL. 



83 



tate which settled rapidly, leaving the filtrate milky in appearance. This 

 precipitate, after decanting the solution, was dissolved in 0.2 per cent potas- 

 sium-hydroxide water and set aside to deposit the suspended impurities. 

 After decantation from the sediment which resulted, the solution was filtered, 

 but almost nothing was thus removed. It was then neutralized with 0.2 

 per cent hydrochloric acid and the precipitate produced washed by decan- 

 tation, first with water and then with dilute alcohol, absolute alcohol, and 

 ether. No attempt was made in this case to obtain the whole of the protein 

 soluble in alkali, as the difficulties presented by slow and imperfect filtration 

 rendered this impossible. The substance thus obtained formed a brownish, 

 horny mass, which weighed 13 grams. This preparation, 89, when dried 

 at no, on analysis gave the results shown in the table at the bottom of this 

 page. 



Subsequent preparations of this body led to the idea that it was far from 

 pure, this supposition being supported by the fact that the final solution 

 from which it had been precipitated was turbid. The remainder of the 

 preparation was then dissolved as completely as possible in 0.2 per cent 

 potassium-hydroxide solution, and by repeated filtration through very dense 

 filter-paper obtained perfectly clear. A considerable insoluble residue 

 remained, which appeared to consist largely of the coagulated form of this 

 protein. This residue was washed by decantation with water, alcohol, and 

 ether. It was found to contain but 13.68 per cent of nitrogen, showing 

 that the preparation, 89, contained much non-nitrogenous matter. The filtra- 

 tion of the dissolved protein proceeded very slowly, so that it was conducted 

 at a temperature near o. A portion of the filtrate first obtained was re- 

 moved, precipitated by 0.2 per cent hydrochloric acid, washed with water, 

 alcohol, and ether, and the preparation, 90, analyzed with the following 

 results. A second portion similarly yielded preparation 91. 



