chapt?:r V 



ANALYSIS OF VARIOUS BIOLOGICAL PROCESSES 



BY THE STUDY OF THE DIFFERENTIAL 



ACTION OF OPTICAL ISOMERS 



Asymmetric Analysis. When one analyses the action 

 upon protoplasmic functions of dextrorotatory and of 

 laevorotatory isomers of various organic substances, one 

 often notices a difference in the effectiveness of the two 

 isomers. The existence or the absence of such a dif- 

 ference, as also its quantitative value, are evidently re- 

 lated to the physical structure and the chemical compo- 

 sition of protoplasm. One can, therefore, study the 

 mechanism of various biological processes by examining 

 how they are influenced by optical isomers of various 

 substances. It is thought that this method of analysis, 

 which we call ''Asymmetric Analysis," could contribute 

 to the clarification of several important problems of 

 comparative physiology. 



With the idea of elaborating some systematic methods 

 of "asymmetric analysis", Gause and his associates have 

 undertaken the following investigations : 1. An analysis 

 was made of the mechanism of toxic action of optically 

 isomeric nicotines upon lower and higher animals. 2. 

 The mechanism of toxic action of optically isomeric or- 

 ganic acids upon lower and higher animals was similarly 

 studied. These two investigations will be reviewed and 

 discussed in the first section of this chapter. The study 

 of the effect of nicotine isomers in various animals led 

 to important observations on the evolution of the ner- 

 vous system. These observations will be discussed in the 

 second section. 3. A study was made of the action of 

 optically isomeric cinchonines upon various functions 

 of the cell. This study will be summarized in the third 

 section, 



99 



