SOME VEGETABLE PROTEIDS. 



131 



containing one gram of the proteid. For purposes of com- 

 parison, the value 



(o) D = -41.5 



probably represents the specific rotation of hemp-seed globulin 

 in such a solution within at least 1. 



Sodium-sulphate Solutions. 



The sodium-sulphate solution used as a solvent was made 

 up to a strength of 10 per cent with sodium sulphate dried in 

 a desiccator, but of only 5 per cent of the anhydrous salt 

 (dried at 110 C.). The hemp-seed globulin was only slightly 

 soluble in this solution at the temperature of the room, and 

 so the globulin solutions were made at a temperature of about 

 35 C. To avoid precipitation during the polarimeter obser- 

 vations, the tubes were warmed to about 50 C. and the 

 solution to 35 or 40 C. before filling. Despite the care 

 taken, several sets of observations were spoiled by the preci- 

 pitation of the globulin. 



Only two independent solutions of hemp-seed globulin were 

 made in the sodium-sulphate solution. The results of the 

 polarimeter observations and from drying down at 110 C. 

 were as follows: 



These results are quite concordant, and show the specific 

 rotation of hemp-seed globulin in a 10 per cent (5 per cent 

 solution of the anhydrous salt) sodium-sulphate solution to 

 be some three degrees less than in a 10 per cent sodium- 

 chloride solution. 



