1841. The ether, under this view, performs the part heretofore assigned to latent heat, by combining with solids so as to render them susceptible of expansion, and of electrical conduction by being liable to the polarization which constitutes electricity.
1842. Sensible heat, according to this aspect, is due to the vibrations of the ethereal fluid, which is sustained by the sun, by ignition in the interior of the earth, and by chemical reaction, including combustion and respiration.
1843. The correctness of the inference, that conductors owe their conductive power to ethereal matter entering into their composition, has been insisted upon in my strictures on Farraday’s speculation in some of the preceding pages. The facts admitted by this distinguished investigator of nature’s laws, gave to me a basis on which to rest an argument in favour of the existence of an imponderable cause of heat and electricity in metals, which seems to me unanswerable.
1844. Agreeably to the hypothesis respecting which the preceding preparatory suggestions have been made, gasification is not due to a repulsive atmosphere of ethereal matter, severally appropriated to each ponderable constituent atom, but to an attraction for every such atom exercised by the ethereal fluid, such as water exercises toward sugar, quick-lime, salt, or any soluble substance. The ether attracts the particles of certain solids, and is of course reacted upon by them. The particles thus attracted naturally distribute themselves throughout it, at symmetrical distances. Hence the law of Pettit and Dulong is verified, which, at least, holds good with all gasifiable atoms, that their capacity is inversely as their atomic weight.
1845. The atomic weights of hydrogen, nitrogen, and chlorine being severally 1, 14, 36, when associated with equal volumes of the imponderable ether, they will have still the same weight. Equal volumes will weigh the same as the atoms with which they are associated; and the capacity for heat, being directly as the volumes, will be inversely as the weights, the calculation being the same, whether ether or caloric be the imponderable principle to which they owe their gasification. By concurring with those chemists, who estimate the atoms of oxygen at 16, instead of 8, this gas will come into the same calculation.
1846. When heterogeneous gases are confined within the same cavity, that they should not react with each other is no more wonderful, than that the same mass of water may at the same time hold different substances in solution, which may add to its hydrostatic pressure though they have no reciprocal reaction.
1847. Sensible heat appears to be due to vibrations in the ether, kept up by the solar rays or central ignition within this globe. By the heat thus acquired the self-repellent power of the ether is augmented. When by refrigeration this source of repulsion is diminished beyond a certain limit, the atoms of certain vaporizable particles, such as those of steam and other condensible vapours, are approximated sufficiently to attract each other, and consequently coalesce and are condensed.
1848. It follows that light is due to undulation, sensible heat to vibration, and electricity to the polarization caused in the ethereal medium, while either in a free, or in a combined state. Thus this luminiferous ether performs the part heretofore attributed to latent heat or caloric in one state; in another state, that of sensible heat.