8* PRESSURE AND ENERGY 367 



On account of this result Boltzmann's theory of osmotic 

 pressure in liquids is important for the kinetic theory of gases. 



Except for this, however, I should not here have mentioned it, 

 since osmotic pressure is not one of the phenomena which the 

 kinetic theory of gases has to explain. I will also not conceal 

 that I do not think van't Hoff's views of the kinetic nature 

 of osmotic pressure to be correct. For osmose does not arise from 

 the kinetic pressure of the dissolved substance, but from quite 

 different forces which cannot be neglected. 



At all events, if the formula is to be applied to osmose, it first 

 needs a correction, which G. Elias Miiller 1 has pointed out ; 

 viz. from the kinetic pressure of the dissolved molecules there 

 must be subtracted the pressure which the displaced particles of 

 liquid would have exerted by their motion. Not till then does it 

 become intelligible that osmose is able to cause a motion of the 

 liquid towards the side of the greater pressure. 



1 Theorie der Muskelcontraction, Leipzig 1891, 1. (App.) p. 321. 



