BY JAMES M. PETRIE. 



101 



Nos. 13, 14 and 15 show the relative amounts dissolved by 

 salt alone, of which 10% is the best solvent. Almost the same 

 amount of protein is dissolved by 10% salt as by 01%alkali. 

 The partially neutralised extracts in the whole series, from 

 1% to 10%, contain more than the salt extracts alone. The 

 maximum protein is obtained in No. 2, by using 0-2% alkali 

 alone. 



Preparation of Solutions for Analysis. — Since little is to be 

 gained by first extracting, with water, those proteins which 

 are also soluble in salt-solutions, the extracts were always 

 made by adding sodium chloride solution directly to the 

 powdered seeds. 



By extracting 20 gms. of seeds with 1 litre of 10% sodium 

 chloride solution for 1 day, an extract was obtained in which 

 the protein-content was determined by precipitation with 

 tannic acid, and the estimation of nitrogen in the precipitate. 

 The residue of seeds was again extracted with a second litre 

 of salt-solution, and the amount of protein-nitrogen esti- 

 mated as before. By successive treatments in this way, until 

 no protein was contained in the final solution, the maximum 

 quantity of protein cajoable of being extracted by sodium 

 chloride solution was ascertained. The results were ii3 

 follows: — 



Ist Extraction yielded 76 % of the whole extractable protein. 



In consequence of the above, the numerous single extracts 

 made for various experiments, give results which are not 

 comparable with one another. 



In order to study the behaviour of these proteins towards 

 the different reagents, an extract was made from 100 gms. of 



