206 W. A. Norton on Molecular Physics. 
the repulsive energy of molecules at the greater distances, as 
given in Table I (p. 68); if we regard the coefficient, m, as con- 
stant, whatever may be the value ofr. In fact the value of m, de- 
pends upon the pressure to which the molecular atmospheres are 
exposed (p. 241, foot note); and this, in gases, must depend main- 
ly upon the barometric pressure, and be constant for the same 
onion It is to be observed that the results given in Table I 
old good for compound molecules, provided as they are with 
their own especial‘atmospheres (p. 241), as well as for simple mole- 
cules. If r, the radius of the atmosphere of the molecule, be 
increased in any ratio, the value of X( =) will be diminished 
7? 
in proportion to the square of this ratio, but if we estimate the 
rce at a given distance, this distance, as expressed in terms of r, 
will be diminished in the same ratio that 7 is increased, and hence 
if the force varies inversely as the square of the distance, its value 
at the given distance will be the same as before. The elastic force 
of molecules posited at the same distance from each other should 
therefore be the same, whatever may be the radius, 7, of the 
molecule, simple or compound. This result depends upon the 
assumption that the force of molecular repulsion varies, beyond 
_acertain limit, inversely as the square of the distance. Table I 
shows that for the smaller values of the ratio, ~ (which should 
m 
be taken for liquids that furnish vapors, and substances that ha- 
bitually exist in the gaseous form), we have nearly reached this 
limit at the distance 80r. 
To this it should be added that the calculations are made upon 
the supposition that the ratio ~ remains constant for each set of 
computations, answering to each special value of “. But as 4 
m 
matter of fact, in the transition from the liquid to the vaporous 
state, as we have seen (p. 75), the molecular atmospheres expand, 
which should diminish the value of n, and of theratio . AC 
cordingly, to represent truly the vaporous state, it is probable 
that the calculations should be made for a smaller value of = 
than any of those given at the head of the Table. If this be 
i Bas uced, This 
be the case especially with the 
Nati aali, perman 
