XIII.] THE BIOLOGICAL SCIENCES AND MEDICINE. 347 



knowing, nothing but changes of place of particles of 

 matter, look to molecular physics to achieve the 

 analysis of the living protoplasm itself into a mole- 

 cular 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 

 immense 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 and planetary systems with the protoplasmic 

 foundation of life and organisation. 



From this point of view, pathology is the analogue 

 of the theory of perturbations in astronomy; and 

 therapeutics resolves itself into the discovery of the 

 means by which a system of forces competent to 

 eliminate any given perturbation may be introduced 

 into the economy. And, as pathology bases itself 

 upon normal physiology, so therapeutics rests upon 

 pharmacology ; which is, strictly speaking, a part of 

 the great biological topic of the influence of conditions 

 on the living organism, and has no scientific founda- 

 tion apart from physiology. 



It appears to me that there is no more hopeful 

 indication of the progress of medicine towards the 



