THE LAWS OF LIFE. 235 



attraction which is termed chemical affinity, there 

 can be little doubt that it includes as one element a 

 tendency to the approximation of certain particles. 

 It is in one aspect, probably in its primary aspect, 

 an approximating force. In this respect it presents 

 an analogy to the force of gravitation, which it can 

 hardlyTead us into error fully to recognize, and 

 on which, indeed, the illustration of the pendulum 

 is based. 



If we now endeavour to carry the conception of 

 the vital process more into detail, the view which 

 has been taken of it affords an easy clue. 



In the act of chemical change certain particles of 

 matter are approaching each other, moved thereto 

 by mutual attracting influences. If it be conceived 

 that from some cause (not as yet denned) the perfect 

 approximation of such particles is prevented, what 

 so naturally ensues as that they pass by and go 

 beyond each other, the very impulse of their 

 attraction becoming thus the source of their sepa- 

 ration ? 



What else have we in life? Is not the living 

 body constituted by certain particles of matter en- 



