rather to hide
than to discover...."

Having thus dwelt in detail on these experiments, Rumford comes now to
the all-important discussion as to the significance of them--the
subject that had been the source of so much speculation among the
philosophers--the question as to what heat really is, and if there
really is any such thing (as many believed) as an igneous fluid, or a
something called caloric.

"From whence came this heat which was continually given off in this
manner, in the foregoing experiments?" asks Rumford. "Was it furnished
by the small particles of metal detached from the larger solid masses
on their being rubbed together? This, as we have already seen, could not
possibly have been the case.

"Was it furnished by the air? This could not have been the case; for,
in three of the experiments, the machinery being kept immersed in water,
the access of the air of the atmosphere was completely prevented.

"Was it furnished by the water which surrounded the machinery? That this
could not have been the case is evident: first, because this water was
continually RECEIVING heat from the machinery, and could not, at the
same time, be GIVING TO and RECEIVING HEAT FROM the same body; and,
secondly, because there was no chemical decomposition of any part of
this water. Had any such decomposition taken place (which, indeed, could
not reasonably have been expected), one of its component elastic fluids
(most probably hydrogen) must, at the same time, have been set at
liberty, and, in making its escape into the atmosphere, would have been
detected; but, though I frequently examined the water to see if any
air-bubbles rose up through it, and had even made preparations for
catching them if they should appear, I could perceive none; nor was
there any sign of decomposition of any kind whatever, or other chemical
process, going on in the water.

"Is it possible that the heat could have been supplied by means of the
iron bar to the end of which the blunt steel borer was fixed? Or by the
small neck of gun-metal by which the hollow cylinder was united to the
cannon? These suppositions seem more improbable even than either of
the before-mentioned; for heat was continually going off, or OUT OF THE
MACHINERY, by both these passages during the whole time the experiment
lasted.

"And in reasoning on this subject we must not forget to consider that
most remarkable circumstance, that the source of the heat generated by
friction in