64 W. A. Norton on Molecular Physics. 
condition of alternating contractions and expansions, or of alter- 
nating inward and outward movements of their atoms, althou 
the primary forces acting upon these atoms should be continuous 
in their action. 
ut if we confine our attention to the action of a single atom 
upon its electric atmosphere, it will be seen that the expansions, 
which of necessity follow the apr arias: must be of less extent 
than the contractions; for a part of the contractile force is ex- 
pended in impelling a portion of the universal ether compressed 
upon the surface of the central atom normally outward from 
this surface. To the extent that this effect takes place will the 
wi of the atmos — exceed the expansion which im- 
lately follows it, an ffective attractive force be propa- 
‘ested through the surrounding electric ether. We are thus led 
to recognize the existence of a third molecular force, viz: a 
force of repulsion originating in the attractive action exerted by 
the atom of the molecule upon its electric atmosphere 
8. A third molecular force, then, consists of a series of repul- 
sive, or outward acting impulses, imparted to the universal 
ether at the surface of the atom of a molecule by the contractile 
force exerted by the atom upon its electric atmosphere. This 
tepulsion is equal, at its origin, to the attraction which developes 
it. It is propagated in waves which, unlike the waves convey- 
ing the other molecular forces, proceed through the universal 
ether. These waves, if each contraction of the ‘atmosphere W were 
not followed by a partial expansion, would be of the character 
f “waves of translation,” and would convey only outward act 
ing impulses ; they are, in fact, oscillatory waves, in which the 
outward predominate over the inward acting impulses, 
The — thus originating may be regarded as the prima 
force of heat, and may be termed heat-repulsion. The other two 
~siac forces may be designated as the forces of electric attrac- 
tion and electric repulsion. But they should not be confounded 
with the special electric forces that come into play ye stn 
the natural quantity of electric ether oe with atoms, of 
present on different sides of atoms, experiences any material in- 
cans or diminution—which will be considered in another con 
Si ie ate eee ale 
