CHEMISTRY 231 



an enzyme possessing the power to select and 

 catalyze any one of the reactions, the for- 

 mation of any special one of the many possible 

 products in comparative purity is an auto- 

 matic result. 



Such processes are in nature carried out 

 with a perfection which to the chemist is 

 almost inconceivable, by means of organic 

 structures of the highest intricacy ; but in 

 the last analysis they rest upon the native 

 properties of the three elements. 



The important consideration, I repeat, is 

 this : that reduction, the necessary first change 

 of carbonic acid and water, can lead directly 

 by a single continuous chemical transforma- 

 tion, of which the exact control is no whit 

 more remarkable than the accurate control 

 of the other processes of chemical physiology, 1 

 to the full intricacy of organic chemistry ; to 

 the very most notable instance of number, 

 variety, and activity of substances, all formed 

 inevitably, in the nature of the case, which 

 has yet come to light. It is of no consequence 

 that most of the substances must be formed 

 in mere traces by the spontaneous synthesis, 

 for in highest degree the organism possesses 

 the power, by enzymatic catalysis, to select 



1 Consult the work of Bayliss on Enzymes. London, 

 Longmans, Green & Company. 



