466 MOSSOTTI.ON THE FORCES WHICH REGULATE 
— ar 
gV(Gta)Sv(mt+q)Atarnjye AX * 
rv 
Sy. ok 
—(9—y) ®@viaw—_——=0 
Ty 
(A) gv(qta)iv(m+q) +anije Rede 
_ (g—y)avEav,P—) =-0 
— @r 
gv(qt+az)iv(mt+q)A+tan)je 
Zy — Z 
ry? 
— (g-—y) vig ='0; 
where the sums © are to be extended to all the members », that is to 
say, to all the molecules except that whose equilibrium we are con- 
sidering. 
7. The equations which we have just found are those which must 
take place in case of equilibrium, or in the natural state of a body com- 
posed of spherical molecules, if Franklin’s hypothesis respecting statical 
electricity may be applied to the constitution of bodies also. Vhe form 
in which the equations present themselves shows that this equiliorium 
takes place exactly as if there existed between each pair of molecules 
a reciprocal action, in the direction of the straight liae wich would 
join their centres of gravity, and would be represented by 
— art 
(a) gv(w+q)v, (a, Pe) aes 
1 
1 
ee eins iF 
Let us examine the nature of this action. We are able to distinguish 
in its expression the products g v (a + q)- v,(@, + qi); (g—y)@y- 
m@,V,, the constant 2 and the variable r,. 
As the difference (gy — y) between these two accelerative forces is 
to be supposed very small relatively to g, the product of this force by 
the masses v (a + q) v, (@, + q,) will, for a twofold reason, be 
greater than the product of the differenee g — y by the masses aw v. w, 
Vi. 
The value a depends on that of fand , that is to say on the repul- 
sive force of the atoms of the ether, their mutual distances, their 
masses, and their volumes, which are all unknown to us. The agree- 
ment of the results of calculation with those of experiment requires 
that a should be avery high number. 
On the condition that @ is very great, the first term of the expression 
(a) will decrease rapidly with r,, because of the multiplier gi tag a 
