﻿Kinetic Theory of Adsorption. 697 



the unit of pressure to cm. of mercury, and taking logarithms. 



P 



log*; =log (7-52 x 10- 8 x f) -0-4343 Q { 



-R Bl 



— -DO. Fpf 



(15) 



X, and therefore B 1? is a function of the temperature, but 

 may probably be taken as constant over a fairly limited 

 range of temperature. Over a wider range, it can probably 

 be expressed 



X = X -/3T, 



which leaves (15) of the same form, B x being then equal to 



04343 ^~ . An isostere of the form (15) is not peculiar to 



the present theory j Williams (loc. cit.) has found the same 

 relation from his assumptions, and a similar form can be 

 derived from Perrin's radiation hypothesis. 



Fur. 3. 



00002 



0-0005 



The Isostere, from Travers's Observations. 



Williams has shown excellent agreement with (15) for a 

 large number of observations of Cbappuis, Homfray, and 

 Richardson ; argon and ammonia deviate at low temper- 

 atures. I have found fair agreement with the measure- 

 ments of Travers (fig. 3), and excellent agreement with the 



