APPLICABLE TO MATHEMATICS, &C. 347 



repulsive force, be replaced by the particles of 

 matter being compelled by a sufficient pressure to 

 take a closer union, the quantity of caloric dis- 

 placed ought to be proportioned to the density of 

 the fluid. 



The experiments necessary to ascertain the 

 truth of this statement, must be, from the subtlety 

 of the subject under consideration, very delicate ; 

 and consequently, the apparatus used for such 

 purposes must be well constructed. 



The forces of attraction and repulsion are 

 intimately connected with all subjects of physical 

 science, but more particularly the theoretical part 

 of chemistry, when the phenomena which takes 

 place in that science are considered to be the 

 effects of molecular action. 



The mineralogical variations which we per- 

 ceive in the earth no doubt owe their origin 

 to the chemical changes which the particles that 

 compose them have been, at very distant periods 

 of the earth's history, subject to. I mean by 

 chemical changes, changes produced by means of 

 the excess of one force which acts on a particle 

 over another force ; the effect, which is the motion 



