148 THE NEW PHYSIOLOGY. 



and consider also the limitless empirical facts of chemistry, 

 we can see that the physical conceptions of extension 

 and central forces connecting masses are nothing but 

 imperfect representations of reality, however useful 

 these imperfect representations may be within certain 

 limits. The reality is far more than these conceptions 

 can express. 



From yet another point of view the abstract mechani- 

 cal conception of a molecule is unreal. We now possess 

 abundant evidence that molecules, just like crystals 

 or other gross molecular aggregates, are in a state of 

 constant decomposition and recomposition. So far may 

 this process go in very dilute solutions of what are 

 distinguished as electrolytes, that for all practical 

 purposes their molecules hardly exist as such, and only 

 the dissociated fragments are present. Thus a very 

 dilute solution of sodium chloride or hydrochloric acid 

 contains, practically speaking, only the ions formed 

 by the dissolution of the molecules of sodium chloride 

 or hydrochloric acid. I need, perhaps, hardly refer in 

 detail to the very great significance of the conception 

 of ionisation first introduced by Faraday, and the 

 manner in which this conception has developed until 

 it has transformed the whole outlook of both chemistry 

 and physics. It is now evident that not merely gross 

 aggregates, but also molecules and atoms, are in a state 

 of constant decomposition, recomposition, and internal 

 action. Their mass and extension appear to be nothing 

 but an expression of this action ; and if so the distinction 

 between matter and energy, or between structure and 

 its activity, becomes only an imperfect representation 

 of the actual world. 



