650 SCIENCE PROGRESS 



the forces between them are very much less than when the 

 molecule is free and in the gaseous state. 



The fallacy which underlies the application of this argument 

 does not appear to have been recognised. It has not been 

 sufficiently taken into account that the resolution of the com- 

 pound A B into A and B under the influence of the water sphere 

 is temporary only, in the sense that it obtains only while the 

 two are in approximation. Their separation is apparent rather 

 than real ; in fact, the dissociation is merely potential and there 

 would seem to be no reason why the superior osmotic effects 

 which, ex hypothesis are due to the free ions alone should be 

 produced by them in the new state of restraint to which they 

 are subject under the inductive influence. 



Apart from the objection that the conception of ionic dis- 

 sociation is opposed to reason and chemical common-sense, 

 there are other specific objections which appear to render the 

 hypothesis untenable. " L'activite chimique se confonde avec 

 l'activite electrolytique " is the expression used by Arrhenius in 

 1883 ; it has misled his followers to the present day. It is true 

 only as regards the order of activity in a series of acids, for 

 example ; it is the reverse of true when the comparison is made 

 for various degrees of dilution : it then appears that whilst mole- 

 cular conductivity increases on dilution, the very opposite is true 

 of hydrolytic activity. The case is one like that propounded 

 by the Duchess when she said, " The more there is of mine, 

 the less there is of yours." If free ions increase in number as 

 a solution is diluted and condition an increased conductivity, 

 if these same ions condition hydrolytic activity, then hydrolytic 

 activity must be directly proportional to the number of free ions. 

 The argument is the same as that favoured by the thermodynamic 

 school, when they confound you by proving that change of a 

 certain character would involve perpetual motion — which is 

 impossible. 



The rigidly selective action of enzymes as hydrolytic 

 catalysts is in no way explicable by the ionic dissociation 

 hypothesis — hydrogen ions, which, ex hypothesi, are the active 

 agents in hydrolysis, cannot be supposed to act selectively. 



Nor can the action of acids as hydrolytic catalysts be 

 explained except from an association standpoint, as when used 



