THE BIOLOGICAL SCIENCES AND MEDICINE. 355 



as little favour as Bicliat did, upon any attempt to 

 apply tlie principles and the methods of physics and 

 chemistry to the investigation of the vital processes of 

 growth, metabolism, and contractility. They stand 

 upon the ancient ways ; only, in accordance with that 

 progress towards democracy, which a great political 

 writer has declared to be the fatal characteristic of 

 modern times, they substitute a republic formed by a 

 few billion of " animulae " for the monarchy of the 

 all-pervading " anima." 



Others, on the contrary, supported by a robust faith 

 in the universal applicability of the principles laid down 

 by Descartes, and seeing that the actions called " vital " 

 are, so far as we have any means of knowing, noth- 

 ing but changes of place of particles of matter, look 

 to molecular physics to achieve the analysis of the liv- 

 ing protoplasm itself into a molecular mechanism. If 

 there is any truth in the received doctrines of physics, 

 that contrast between living and inert matter, on which 

 Bichat lays so much stress, does not exist. In nature, 

 nothing is at rest, nothing is amorphous; the simplest 

 particle of that which men in their blindness are pleased 

 to call " brute matter " is a vast aggregate of molecular 

 mechanisms performing complicated movements of im- 

 mense rapidity, and sensitively adjusting themselves to 

 every change in the surrounding world. Living matter 

 differs from other matter in degree and not in kind; 

 the microcosm repeats the macrocosm ; and one chain 

 of causation connects the nebulous original of suns 



