CHAPTER I 



OPTICAL ACTIVITY OF BIOLOGICAL MATERIAL 



1. Dissymmetry in Organic and in Inorganic Nature. It 

 has been repeatedly pointed out that all physiologically 

 important substances possess a dissymmetric structure. 

 This is precisely what Pasteur meant when he wrote: "On 

 trouve la dissymetrie etablie notamment dans les principes 

 immediats essentiels a la vie. ' ' But is there any essential 

 relation between dissymmetry and life, in the sense that 

 one is a necessary attribute of the other! Dissymmetry 

 is certainlj^ much more general than life. We know that 

 the dissymmetric structure exists in crystals of quartz. 

 The same is true of several metallic compounds {cf. Lowry, 

 1935). Recently Jaeger (1919), after having investigated 

 a great number of inorganic compounds, came to the con- 

 clusion that the dissymmetric structure might be much 

 more general than we usually assume, but that, in inorganic 

 nature, the existence of dissymmetry is often difficult to 

 establish, there being no method for separating the anti- 

 podes. Vernadsky (1934) made a similar remark. In 

 such cases at least, dissymmetry^ has no obvious relation 

 to life. But, if dissymmetry exists without life, life might 

 not exist without dissymmetry. The possibility that life 

 be the attribute of systems built of substances of such a 

 level of complexity that dissymmetry is the very condition 

 of their existence is not excluded. A suggestion which was 

 recently made by Ackermann (1935), and which is practi- 

 cally identical with that of Pasteur (1884), is that dissym- 

 metry is characteristic of the basic components of proto- 

 plasm, whilst such products of metabolism as urea, uric 

 acid, creatinin and hippuric acid are devoid of dissym- 

 metry and their molecules are structurally inactive. The 

 simplest amino-acid of the protein molecule, glycocoll, is 



