130 



THE ROTARY PROPERTIES OF 



Sodium-chloride Solution*. 



The mode of preparing these solutions has already been 

 described. Hemp-seed globulin is fairly soluble in a 10 per 

 cent sodium-chloride solution at temperatures above 20 C. At 

 15 C. it is much less soluble, and at 10 C. it is only very 

 slightly soluble. The solutions of hemp-seed globulin are of 

 a brownish-yellow color. Although somewhat opaque, the 

 writer was able to use solutions containing as much as 2 or 

 3 per cent of the proteid in a 100 millimeter tube. 



Four independent solutions of hemp-seed globulin were 

 made in a 10 per cent sodium-chloride solution, and the 

 percentage of globulin in solution was determined by drying 

 at 110 C. The results of the polarimeter observations with 

 these solutions are shown in the following table : 



With the exception of those for solutions containing 0.97 

 and 0.92 per cent of globulin, the values obtained for (<z) D 

 agree well within the given limits of error. In general they 

 seem to indicate a decrease in the rotary power of the globulin 

 with the percentage in solution. Assuming such a decrease 

 in the rotary power, by interpolating and extrapolating for 

 each separate solution and averaging the results we obtain 

 (a) D = 41.6 0.5 as the specific rotation of hemp-seed 

 globulin dissolved hi a 10 per cent sodium-chloride solu- 

 tion, each 100 cubic centimeters of the resultant solution 



