profession have weaned Justice Grove from science; for, while it may
be possible to find in the ranks of the Bar many who might worthily
occupy his place on the Bench, it would be hard to find among men of
science any with as wide-reaching and practical philosophy as that
which he owns. The chemist demonstrated long since that it was
impossible for man to create or destroy a single particle of
ponderable matter; but it remained for our own time to prove that it
was equally impossible to create or destroy any of the energy which
existed in nature as heat, mechanical power, electricity, or chemical
affinity. All that it is in the power of man to do is to convert one
of these forms into another. This, perhaps the greatest of all
scientific discoveries since the time of Newton, was first, I believe,
enunciated in 1842 by Grove, in a lecture given at the London
Institution; and it was experimentally proved by the researches of
Joule, described in a paper which he read at the meeting of the
British Association which was held at Cork--my native city--in 1843.
My friend Dr. Sullivan, now President of Queen's College, Cork, and I
myself had the privilege of being two of a select audience of half a
dozen people, who alone took sufficient interest in the subject to
hear for the first time developed the experimental proof of the theory
which welds into one coherent system the whole physical forces of the
universe, and enables one of these to be measured by another. One
branch of the "correlation of physical forces," as it was termed by
Grove, was the relation between mechanical power and heat, and the
convertibility of each into the other, which, under the name of
"Thermodynamics," has become one of the most important branches of
practical science.

Joule's first experiments clearly proved that each of these forms of
energy was convertible into the other; but some discrepancies arose in