54 PROFESSOR KELLAND, ON MOLECULAR EQUILIBRIUM. 



= -33 (1 + ««) 



a 0! 



|>/p (1+a/e 1-aZe } — i — V 



which is a very simple form, and is perfectly general, with the only 

 exception, that we have omitted all consideration of the caloric displaced 

 by the material particles between A and B. 



33. In order to complete the expression, all that remains to be 

 done is to find the value of Je or h. 



Now h evidently varies as the force on an individual particle of 

 caloric at the surface of a. material particle. 



The expression parallel t;o x for this force is then 



This may be divided into two parts, the one that which depends on the 

 particle of matter at whose surface the force is supposed to act, the other 

 the united effect of all the other particles. With respect to the latter, it 

 is easy to observe that the force at the centre of the molecule is 

 zero, and consequently that at the surface will be the variation of the 

 whole force by the variation of X through the space I. 



Let, therefore, F be the whole force in one direction on a particle 



of caloric in the position of the centre of the particle of matter; then 



2dF 

 will , / be the term in question. 



34. We have therefore to find 



V^e-""(l + aR) = G. 



Let the whole mass be intersected by planes at the distances re- 

 spectively of the particles, and parallel to yz : e the distance between 

 two consecutive particles : >) the distance of the particle acted on from 

 the first plane, »? + re is the distance of any plane. 



