118 



ASYMMETRIC ANALYSIS 



mg. per 100 gr. of weight as compared to 5.6 mg. per 100 

 gr.), but, practically, this difference in sensitiveness does 

 not influence the stereo-coefficient. The constancy of the 

 latter, despite a different sensitiveness, is also significant 

 in the study of the properties of the specific receptive 

 substance. 



The results of investigations on the toxic action of the 

 two optical isomers of nicotine on fresh water and marine 

 invertebrates are given in Table 19. One sees that all 

 the invertebrates examined by Gause and Smaragdova 

 can be divided into two groups. The first includes the 

 animals for which the dextro and laevo isomers are equal- 

 ly toxic, and for w^hich the toxicity curves of the two 

 isomers fullv coincide. The second includes the organ- 



TABLE 19 

 Comparative Killing Action of the Optical Isomers of Nicotine on 



Invertebrates 

 (Tiie sign = means that d and 1 nicotines are equally toxic; the coeffi- 

 cient (X indicates to what degree 1 is more toxic than d nicotine.) 



