RELATION OF PHYSIOLOGY TO MEDICINE. 89 



expression, but it at least points to the great salient 

 facts which distinguish an organism from such machines 

 as we know, and completely differentiate medicine 

 from all mechanical and chemical arts. To put the 

 matter in simpler and less misleading language, it is 

 organic regulation of both structure and activity that 

 we are constantly trying to aid and supplement in 

 medicine and surgery. 



I do not wish to go into the question whether organic 

 regulation is, or is not, ultimately reducible to mechanism. 

 On this point I have fully expressed my own conclusions 

 elsewhere, but they need not directly affect the matter 

 we are now discussing. My immediate point is this : 

 that in practical medicine the assumption of the existence 

 of organic regulation of both structure and function 

 is absolutely fundamental. Disease is the breakdown 

 of this regulation at one point or another ; and practical 

 medicine is simply assistance to Nature in restoring and 

 maintaining effective organic regulation. 



Now let us turn to physiology as it is usually taught 

 at present. On consulting a current text-book of physio- 

 logy one finds an account of the mechanical and physical 

 aspects of each bodily process taken separately. For 

 instance, in the case of breathing, there are descriptions 

 of the structure of the lungs, the mechanism by which 

 air is driven in and out of the lungs, the chemical changes 

 in the air breathed, the means by which gaseous exchange 

 occurs in the lung alveoli, the nervous channels by which 

 inspiratory and expiratory impulses are conveyed from 

 the respiratory centre to the muscles, and the chemical 

 and nervous stimuli which act on the centre. All these 

 things are systematically described one by one, as we 



