attracted no attention whatever. In 1847,
when another German physician, Hermann von Helmholtz, one of the most
massive and towering intellects of any age, had been independently
led to comprehension of the doctrine of the conservation of energy
and published his treatise on the subject, he had hardly heard of his
countryman Mayer. When he did hear of him, however, he hastened to
renounce all claim to the doctrine of conservation, though the world at
large gives him credit of independent even though subsequent discovery.

JOULE'S PAPER OF 1843

Meantime, in England, Joule was going on from one experimental
demonstration to another, oblivious of his German competitors and almost
as little noticed by his own countrymen. He read his first paper before
the chemical section of the British Association for the Advancement of
Science in 1843, and no one heeded it in the least. It is well worth our
while, however, to consider it at length. It bears the title, "On the
Calorific Effects of Magneto-Electricity, and the Mechanical Value
of Heat." The full text, as published in the Report of the British
Association, is as follows:

"Although it has been long known that fine platinum wire can be ignited
by magneto-electricity, it still remained a matter of doubt whether heat
was evolved by the COILS in which the magneto-electricity was generated;
and it seemed indeed not unreasonable to suppose that COLD was produced
there in order to make up for the heat evolved by the other part of
the circuit. The author therefore has endeavored to clear up this
uncertainty by experiment. His apparatus consisted of a small compound
electro-magnet, immersed in water, revolving between the poles of a
powerful stationary magnet. The magneto-electricity developed in the
coils of the revolving electro-magnet was measured by an accurate
galvanometer; and the temperature of the water was taken before and
after each experiment by a very delicate thermometer. The influence of
the temperature of the surrounding atmospheric air was guarded against
by covering the revolving tube with flannel, etc., and by the adoption
of a system of interpolation. By an extensive series of experiments with
the above apparatus the author succeeded in proving that heat is evolved
by the coils of the magneto-electrical machine, as well as by any other
part of the circuit, in proportion to the resistance to conduction
of the wire and the square of the current; the magneto havi