rees centigrade) has a greater bulk after being
shaken than it had before. Whence now comes this quantity of heat, which
by repeated shaking may be called into existence in the same apparatus
as often as we please? The vibratory hypothesis of heat is an approach
towards the doctrine of heat being the effect of motion, but it does not
favor the admission of this causal relation in its full generality. It
rather lays the chief stress on restless oscillations.

"If it be considered as now established that in many cases no other
effect of motion can be traced except heat, and that no other cause
than motion can be found for the heat that is produced, we prefer the
assumption that heat proceeds from motion to the assumption of a cause
without effect and of an effect without a cause. Just as the chemist,
instead of allowing oxygen and hydrogen to disappear without further
investigation, and water to be produced in some inexplicable manner,
establishes a connection between oxygen and hydrogen on the one hand,
and water on the other.

"We may conceive the natural connection existing between falling force,
motion, and heat as follows: We know that heat makes its appearance
when the separate particles of a body approach nearer to each other;
condensation produces heat. And what applies to the smallest particles
of matter, and the smallest intervals between them, must also apply to
large masses and to measurable distances. The falling of a weight is a
diminution of the bulk of the earth, and must therefore without doubt be
related to the quantity of heat thereby developed; this quantity of heat
must be proportional to the greatness of the weight and its distance
from the ground. From this point of view we are easily led to the
equations between falling force, motion, and heat that have already been
discussed.

"But just as little as the connection between falling force and motion
authorizes the conclusion that the essence of falling force is motion,
can such a conclusion be adopted in the case of heat. We are, on the
contrary, rather inclined to infer that, before it can become heat,
motion must cease to exist as motion, whether simple, or vibratory, as
in the case of light and radiant heat, etc.

"If falling force and motion are equivalent to heat, heat must also
naturally be equivalent to motion and falling force. Just as heat
appears as an EFFECT of the diminution of bulk and of the cessation
of motion, so also does heat di