THE 



AMERICAN NATURALIST 



Vol. LI. June, 1917 No. 606 



BIOLOGICAL ENIGMAS AND THE THEORY OF 

 ENZYME ACTION 



DR. LEONARD THOMPSOX TKOLAXD 

 Harvard Uxiversity 



DuKiNG the past twenty years the sciences which deal 

 with inorganic physical phenomena have made astound- 

 ing progress in the logical sjTithesis of their facts and 

 theories.^ The beginnings of this s^^ithetic tendency lie, 

 of course, in the middle ])art of tlie hi>t century, in the 

 work of such men as Faraday. Maxwell, and ^[eiidelejoff. 

 The discovery of radio-activity by J >( ('<|iu'rel in and 

 the demonstration by Thomson of the electron, in the fol- 

 lowing year, let loose the pent-up forces of an intellectual 

 avalanche which swept scientific conservatism quite off its 

 feet, and seems to be carrying our thought with thrilling 

 rapidity towards a goal which metaphysical philosophers 

 have for ages regarded with wistful longing. Tliis goal 

 is the comprehension of the i»liysical universe in terms of 

 a few simple conceptions. 



The lines of demarcation which once were so rigidly 

 drawn between the departments of physical science are 

 disappearing before our eyes. The discovery of radio- 

 activity, instead of adding a new science to the list, has 



1 D. F. Comstock and the present writer have attempted to give an ele- 



