372 ON PHYSICAL DATA 



chemical equilibrium takes place, will be repre- 

 sented by ^^-^Vtg ; 4^^x# &c. &c. &c., which 



we shall call the forces of rigidity of the material 

 particles when they are placed at distances 

 (Xi+h), (,2?2+7i), &c. from each other respectively. 

 These molecular attractive forces must be small 

 in all fluids, when they are at an ordinary 

 temperature : for water below thirty-two degrees 

 they increase, although the particles are com- 

 pelled to take different roots of the equation 

 F(.r) = . 



The force required to overcome the repulsive 

 force when chemical equilibrium takes place, will 



^^ -l^Sf-' -1^^ ^«- ^^- ^^•' ^^^^^ ^*^ 

 shall call the forces of compression. 



These forces are great in water at all tempe- 

 ratures above thirty-two degrees of Fahrenheit. 



Hence, for the compressive force of bodies to be 

 equal to the tensile, we must have the conditions 



F{x,)=~Y(x.^ 



Y(x,)=-F{x,) 



&c. &c. &c. 



