IX] OF MOLECULAR ASYMMETRY 651 



elaborated by Japp in a celebrated lecture*, and the distinction 

 still Has its weight, I believe, in the minds of many chemists. 

 "We arrive at the conclusion," said Professor Japp, "that the 

 production of single asymmetric compounds, or their isolation from 

 the mixture of their enantiomorphs, is, as Pasteur firmly held, the 

 prerogative of life. Only the living organism, or the Hving intelH- 

 gence with its conception of asymmetry, can produce this result. 

 Only asymmetry can beget asymmetry." In these last words 

 (which, so far as the chemist and the biologist are concerned, we 

 may acknowledge to be truef) lies the crux of the difficulty. 



Observe that it is only the first beginnings of chemical asymmetry 

 that we need discover; for when asymmetry is once manifested, 

 it is not disputed that it will continue "to beget asymmetry." 

 A plausible suggestion is at hand, which if it were confirmed and 

 extended would supply or at least sufficiently illustrate the kind of 

 explanation that is required. We know that when ordinary non- 

 polarised light acts upon a chemical substance, the amount of 

 chemical action is proportionate to the amount of light absorbed. 

 We know in the second place J that light circularly polarised is 

 absorbed in certain cases in different amounts by the right-handed 

 or left-handed varieties of an asymmetric substance. And thirdly, 

 we know that a portion of the light which comes to us from the sun 

 is already plane-polarised hght, which becomes in part circularly 

 polarised, by reflection (according to Jamin) at the surface of the 

 sea, and then rotated* in a particular direction under the influence 

 of terrestrial magnetism. We only require to be assured that the 

 relation between absorption of light and chemical activity, will 

 continue to hold good in the case of circularly polarised light; 

 that is to say that the formation of some new substance or other, 

 under the influence of light so polarised, will proceed asymmetrically 

 in consonance with the asymmetry of the light itself; or conversely, 



* F. R. Japp, Stereochemistry and vitalism, Brit. Ass. Rep. (Bristol), 1898, p. 813; 

 cf. also a voluminous discussion in Nature, 1^98-91). 



. t They represent the general theorem of which particular cases are found, for 

 instance, in the asymmetry of the ferments (or enzymes) which act upon 

 asymmetrical bodies, the one fitting the other, according to Emil Fischer's well- 

 known phrase, as lock and key. Cf. his Bedeutung der Stereochemie fiir die 

 Physiologie, Z. f. physiol. Chemie, v, p. 60, 1899, and various papers in the Ber. 

 d. d. cheni. (Jes. from 1894. 



+ Cf. Cotton. Ann. de Chim. el de Phys. (7), viii, pp. 347-432 (cf. p. 373), 1896. 



