caloritie element with the electrical phenomena so exhibited. 
It was stated that his (Mr. Dyer’s) heat-force theory was in 
strict accordance with Dr. Black’s_ latent heat doctrine, and 
that it went to support it, and to explain some anomalous 
cases that had been adduced against the beautiful system of 
latent heat so long an established basis of wide ranges of 
phenomena, alike in nature and in art. Considering that the 
“ force-heat theory ” is inconsistent with Dr. Black’s, and as 
this latter is embodied on most of the standard works on 
physics, it should not be abandoned to make way for another 
theory that fails to account for such phenomena. Apart from 
the mutations of heat from chemical changes, the mechanical 
action of the earth’s movements was described as exhibiting 
magnetic and luminous phenomena, by the movements of 
elemental heat, proving these also to be identical with it, and 
with electricity. He then proceeded to show the sameness of 
light and heat, as proved by the many incontrovertible 
instances advanced of their inseparable connection, and mutual 
convertibility into each other; and thus finally arrived at the 
sole inference fairly to be drawn therefrom, namely, that heat 
and light, as also heat, electricity, and magnetism, are only so 
many different conditions in which the one calorific element 
exists in nature, and manifests itself by its mutations in 
phenomena. 
Dr. Joule described the experiments he had made many 
years ago on the thermal effects of the dilation of elastic fluids, 
which he considered fatal to the doctrine of the materiality of 
heat. He called attention to the experiments which Mr. 
Dyer had made twenty years ago, indicating the possibility of 
generating heat by the agitation of water. These experiments, 
he believed, would prove to be of great interest to the history 
of science, and trusted that the Author would be able to place 
them before the Society. 
