108 



ASYMMETRIC ANALYSIS 



B. TOXIC ACTION OF THE OPTICAL ISOMERS OF ORGANIC ACIDS 



1. A Case of Different Mechanism of Action of the Two 

 Optical Isomers. In the cases reported so far the natural 

 isomer was more powerful in its physiological action than 

 the unnatural, the relation of increasing toxicity to con- 



0.00330 000340 



Reciprocal of absolute temperature 



Fig. 16. Effect of temperture on the killing rate of Paramecium 

 caudatum by the optical isomers of cinchonine. The lower graph rep- 

 resents the killing rate plotted logarithmically. (From Gause, Smar- 

 agdova and Alpatov, 1938.) 



