THE following Treatise is an attempt to present in a single view, the most important facts at present known on the subject of heat, and to deduce a theory which, if it does not comprehend all the phenomena, is at variance with none. The French writers on the subject have adopted the title "Theory of Heat" to express the mathematical solution of the problems of Radiation and Conduction, but with the exception of M. Ampère's suggestions, no attempt that I am aware of has been made to combine the varied and apparently opposed characters which present themselves to our view in regarding heat as the agent of expansion, whilst it exhibits all the properties of a state of vibration. The hypothesis which makes heat a substance is utterly incapable of accounting for phenomena analogous to those of light, at least in a manner at all consistent with the explanation (now generally deemed correct beyond dispute) of the parallel properties, whilst on the other hand the supposition of a vibratory motion appears to be totally inconsistent with the facts of latent heat and expansion. The former being a Statical hypothesis is |