2Q9 
Chase. | 392 [Feb. 16, 
CORRELATIONS OF COSMIGAL AND MOLECULAR FORCE. 
By Purny Earie Crass, 
Professor of Physics in Haverford College. 
(Read before the American Philosophical Society, February 16th, 1872.) 
If it be granted 
1. That all forms of terrestrial organic energy are transformed modifica- 
tions of solar radiation ; 
2. That centrifugal and centripetal energies tend continually to equilib- 
rium ; 
3. That the kinetic energy of a perfectly elastic medium under constant 
pressure, bears a definable ratio to its kinetic energy under constant 
volume ; 
Then the kinetic energy of dissociated water should be, approvimately, to 
the kinetic energy of terrestrial revolution, as the mass of the earth, is to 
the mass of the sun. 
And the energy of hydrocarbons should be, upproximately, to the energy 
of dissociated water, as elastic energy under constant volume, ts to elastic 
energy under constant pressure. 
For the measures, of the energy of gaseous combustion, and of the 
energy of orbital revolution, are, respectively, the mean height of oscilla- 
tion excited by the igneous energy of the combustible compound, and 
the mean distance from the sun at which the earth is sustained in its 
orbital revolution. It is evident, from the well known laws of elasticity, 
that if a perfectly elastic body were lifted, in vacuo, to any given height, 
and then let fall, it would rebound to the height from which it fell, and 
this oscillation would be perpetual, unless disturbed by extraneous forces, 
in the same way, and for a similar reason, that the earth continues its 
elliptical oscillation about the sun. Inasmuch as the total radiating force 
is considered in each instance, [the time consumed in storing up and in 
liberating the accumulated solar energy being left entirely out of ques- 
tion, | the element of velocity is not involved in the preliminary deter- 
mination. It may, however, be subsequently ascertained, if desired, by 
the formula, 
avo gh. 
It is evident that the dissociated oxygen and hydrogen tend to expand, 
in consequence of any liberated interior energy, under constant exterior 
pressure, while the hydrocarbons are restrained by the cohesive forces 
which tend to maintain a constant volume. 
For the purpose of testing the accordance, both of the postulates and 
of the conclusions, with the facts of observation and experiment, it might 
be deemed sufficient to confine attention exclusively to the lightest and 
most elastic gas, and to the lightest and most volatile liquid. But I 
believe the same principles, with simple modifications, are applicable to 
all forms of matter, and I have already extended the investigation, with 
some encouraging results, to inorganic elements and compounds. I sub- 
join, from Muspratt’s Chemistry, all the elements and products involved 
