SOME VEGETABLE PROTEIDS. 



143 



Effect of Solvent. The following results obtained with the 

 globulin from hemp-seed show that the salt solution used as a 

 solvent was not without influence on its rotary power : 



Solvent. 



10 per cent sodium-chloride solution . . 

 10 per cent ammonium-sulphate solution . 

 10 per cent sodium-sulphate 1 olution 



Equals 6 per cent anhydrous salt J 



Value of (a) D . 

 -41.5 

 -40.0 



-38.6 



Alkali-albumins. The differences in the specific rotations of 

 the globulins studied have already been noted. Their alkali- 

 albumins also differ in their rotary powers in the same order, 

 as the following table shows : 



Alkaline and Acid Solutions. The globulin from hemp-seed 

 was the only one whose rotary power was investigated in dilute 

 alkaline and acid solutions. In general, as with other proteids, 

 the effect of the alkali or acid was to increase the specific 

 rotation from 50 to 100 per cent, this increase being great- 

 est in the acid solutions. Except in the sodium-carbonate 

 solution, the increase in the rotary power took place almost 

 immediately, and heating the solution did not materially alter 

 its value. When dissolved in 0.2 per cent hydrochloric acid 

 there was at first a large increase and then a slight decrease in 

 the rotary power of the proteid. The following are the results 

 obtained with alkali and acid solutions : 



* This was the value of (a) D after heating the solution. Heating in* 

 creased it. 



t Heating this solution did not materially affect the value of (a)o. 



