208 W. A. Norton on Molecular Physics. 
rom our present theoretical point of view, such possible 
changes of condition consist in compressions, or expansions, 
of the molecular atmospheres; either as a whole, or unequally 
on different sides. In the former case there will a varla- 
tion in the size of the atmosphere, and in the intensities of 
the forces of attraction and repulsion exerted by the molecule 
at a given distance, but the forces exerted in different directions 
will have an equal intensity. In the latter case there will bea 
variation in the form of the atmosphere, and an inequality 
of action in different directions. The form assumed will be 
spheroidal, or approximately so, supposing it to have been 
rection of such axes, then, the limit of stable equilibrium (02, 
fig. 1, p. 71) will be least for the shorter axis, and greater for 
When a force of pressure applied to a body determines a peel 
h 1 } + 1 nm PAMTND 
evolved would be absorbed again. In 
. 
general when mechani- 
| to a body, the heat evolved, or absorbed, 
. a hecessa’ P ego: is the Pp , Or be gerne 
‘superinduced in the atmospheres of the pa articles, may be 
