204 _ W. A. Norton on Molecular Physies. 
pois from the condensation of the ‘actiie oes that takes 
lace between the uniting particles, and from the compression of 
their individual one or both of these effects. 
Both of these _— should give rise to an emission of universal 
ether in: ce 
Loos iee that precedes the combination should occasion a loss © 
eat, by reason of the e expansion of the electric ether conde nsed 
mations by the reverse ek ant F develop heat. If the loss 
of heat from the one cause exceeds the gain from the other, 
there will be an effective absorption of heat, as the result of the 
combination. On the other hand, when chemical eget 
occasions an evolution of heat it is in general because the heat 
- ppg onesie much ne heat is lost in the 
eet of the binary oxygen than TO- 
duced poten union of the two separated leslie ae 
atoms) of oxygen, each with a molecule of hydrogen. In so 
instances, as in 7 e formation of the hydrate of lime, the pt 
cules would seem to combine, without any previous decompost 
tion, and any ae on —— to absorption of heat. 
decomposi — - as well as in their combination, a 
is found that either -be absorbed or evolved. This 
fact admits cP a wa lar nea to that just given. M. 
oo Van der Kolk, in a @ memoir on the mechanical energy 
emical action, of which an abstract is given in the January 
noe Re SE eT Oe a ee 
