On the Nature of Chemical Force. 135 



non-electrolytes. Such heterogeneity may be due, for in- 

 stance, to the inverse square law holding for the electric 

 force while another law holds for the cohesive force. Of 

 course, this does not imply that cohesive forces may not be 

 electrical in origin. 



In this paper an attempt is made to show that if the 

 forces causing ionization are of the cohesive type, and those 

 causing recombination of the ions electrical, the anomaly of 

 strong electrolytes can be accounted for, and a theoretical 

 significance given to some empirical laws found to hold, such 

 as the Pudolphi equation. 



Forces of a higher inverse power than the second have 

 been suggested from time to time. Sutherland (Phil. Mag. 

 [6] iv. p. 625 (1902)) and JReinganum (Physikal. Zeitschr. ii. 

 p. 241 (1901) ; Drude's Annalen, x. p. 334 (1903)) on the 

 theory of the electrical doublet proposed the inverse fourth- 

 power law for inter-molecular forces ; but while it is easy to 

 regard a molecule, say of KC1, as a doublet, it is almost 

 impossible to regard a K' or a CI' ion as such, from the 

 modern view-point of atomic and ionic structure. So there 

 seems to be an essential difference in the mode of action of 

 inter-ionic from inter-molecular and ionic-molecular forces. 

 Perhaps the most conspicuously successful application of 

 the inverse fourth-power law to inter-molecular forces is 

 van der Waals' equation of state. 



In an element of volume 8 V let there be 8m x moles of the 

 respective ions and 8m 2 moles of undissociated molecules, 

 and let the relative velocities of any two dissimilar ions in 

 the small volume chosen, at a given instant lie between 



Vi ~ and vi+ — ^ . Similarly, let the velocity of separa- 

 tion of the ionic constituents of any molecule in the volume 

 lie between v 2 ^- and v 2 + -~- • 



2 



Then rate of formation of molecules = v± x .y,- 2 



(Smy 



(8V)' 



8m 2 

 ions — -k^t x v 2- 



(8mi) 2 /8m 2 __ v 2 



(ST) 7 8V - vi 



01 early, at equilibrium 



Let the mean distance apart at the same instant of the 



