encountered, indeed, at every step, anomalies which appeared to me
inexplicable, in accordance with the theories formally recognized. For
the sake of illustration I will quote one instance: 1st, a mass of gas,
under a pressure of ten atmospheres, is contained in a space which is
suddenly doubled; the pressure falls to five atmospheres. 2d. Two
reservoirs of equal capacity are placed in a calorimeter; the one is
filled with a gas, under a pressure of ten atmospheres; the second is
perfectly empty. In these two experiments, the initial and final
conditions of the gas are the same; but this identity of condition is
accompanied by calorific results which are very different; for while in
the former experiment there is a reduction of temperature, in the second
the calorimeter does not indicate the slightest alteration of
temperature." This experiment tends to confirm the theory. In the first
experiment, the sudden doubling of the space causes the ether also to
expand, inasmuch as the sides of the vessel prevent the instantaneous
passage of the external ether. In the second, both vessels are full, one
of ether, and the other of air mixed with ether; so that there is no
actual expansion of the space, and consequently no derangement of the
quantity of motion in that space.


LAW OF SPECIFIC HEAT.

From this view it is evident that the specific heat of elastic fluids
can only be considered as approximately determined. If equal spaces
possess equal momenta, and the ethereal or _tomic_ matter be inversely
as the weight of the atomic matter in the same space, it follows that
the product of the specific gravities and specific heats of the simple
gases should be constant; or that the specific heats should be inversely
as the specific gravities,--taking pound for pound in determining those