142 



THE ROTARY PROPERTIES OF 



The rotary power of this solution was determined within 

 three hours after making up, and again after heating to 50 C. 

 for twenty minutes, with the following results : 



The value of (a) D obtained after warming the solution 

 agrees, within the limits of error, with that obtained before 

 warming it. It is therefore obvious that the full action of the 

 alkali is exerted without the aid of heat.* 



V. SUMMABY AND CONCLUSIONS. 



The specific rotation obtained from 10 per cent sodium- 

 chloride solutions, containing about 1 per cent of proteid 

 matter, were as follows: 



Hemp-seed globulin 

 Brazil-nut globulin 

 Flax-seed globulin . 



(a) D = -41.5 

 (a) D = -40.5 

 (a) D = -38.6 



The differences in the rotary powers of these substances are 

 not very large or unexpected when we consider the slight 

 differences in their chemical composition and behavior, and 

 in their content of ash. 



Effect of Dilution. The observations made with sodium- 

 chloride solutions of these globulins showed in general a de- 

 crease in the rotary power with the percentage of proteid in 

 solution, although the observations were not sufficiently accu- 

 rate to determine the rate of this decrease. 



Effect of Temperature. As already stated, the changes in 

 the specific rotation with the temperature were apparently 

 very slight, and no attempt was made to determine them. 



* In summarizing, the values of (a) D are given to the nearest 0.6. 



