296 INSTRUCTION IN PHYSIOLOGY xi 



with logical rigour. But many of us are old 

 enough to recollect that the administration of 

 chloroform in assuagement of the pangs of child- 

 birth was, at its introduction, strenuously resisted 

 upon similar grounds. 



I am not sure that the feeling, of which the 

 doctrine to which I have referred is the full 

 expression, does not lie at the bottom of the 

 minds of a great many peop]e who yet would 

 vigorously object to give a verbal assent to the 

 doctrine itself. However this may be, the main 

 point is that sufficient knowledge has now been 

 acquired of vital phenomena, to justify the 

 assertion, that the notion, that there is anything 

 exceptional about these phenomena, receives not a 

 particle of support from any known fact. On the 

 contrary, there is a vast and an increasing mass of 

 evidence that birth and death, health and disease, 

 are as much parts of the ordinary stream of events 

 as the rising and setting of the sun, or the changes 

 of the moon ; and that the living body is a 

 mechanism, the proper working of which we term 

 health ; its disturbance, disease ; its stoppage, 

 death. The activity of this mechanism is de- 

 pendent upon many and complicated conditions, 

 some of which are hopelessly beyond our control, 

 while others are readily accessible, and are capable 

 of being indefinitely modified by our own actions. 

 The business of the hygienist and of the physician 

 is to know the range of these modifiable conditions, 



