frigoric

Noun

 * 1) A hypothetical fluid medium of cold, in analogy to caloric.
 * 2) * 1806 M. Dispan, Professor of Chemistry at Toulouse:. "Observations on the Congelation of Water".  А Journal of Natural Philosophy, Chemistry, and the Arts. VOL. XV. pp. 251-253
 * However abundant may be the deposition of hoar frost, the water beneath a bridge will receive no part of it. The surface of the water has therefore this cause of refrigeration less than at the other parts. Its caloric is not taken away but by the mere contact of the air. This condition would be sufficient to render its congelation much more slow; but its fluidity is not less preserved by its surface being defended from the predominating action of the hoar frost, which would follow if that obstacle were not interposed. These facts enabled me to explain certain experiments urged by a philosophical gentleman at Paris a few years ago, to support his opinion on the existence of a material principle under the name of frigoric. The author of these experiments assured me, that in a frosty night the frigoric fell perpendicularly from the atmosphere upon the surface of the earth; and he offered the following proof. If plates filled with water be exposed to the open air at night, and it be cold enough, the water will freeze; but if one of these vessels be covered with a pane of glass, or any other body, that water will not freeze, even though the covering body do not rest immediately upon the plate. It is sufficient, continued the author, that the fall of the frigoric be interrupted, no matter whether from an higher or lower distance; and to complete his demonstration, he added the following experiment, which at first aspect seems very cogent, and is certainly very interesting. It is as follows: place in the evening, at a certain distance above a plate filled with water, a funnel, of which the diameter shall be less than that of the plate, you will find the next day a ring of ice formed round the circumference; but all the water situated perpendicularly beneath the funnel will remain fluid.
 * However abundant may be the deposition of hoar frost, the water beneath a bridge will receive no part of it. The surface of the water has therefore this cause of refrigeration less than at the other parts. Its caloric is not taken away but by the mere contact of the air. This condition would be sufficient to render its congelation much more slow; but its fluidity is not less preserved by its surface being defended from the predominating action of the hoar frost, which would follow if that obstacle were not interposed. These facts enabled me to explain certain experiments urged by a philosophical gentleman at Paris a few years ago, to support his opinion on the existence of a material principle under the name of frigoric. The author of these experiments assured me, that in a frosty night the frigoric fell perpendicularly from the atmosphere upon the surface of the earth; and he offered the following proof. If plates filled with water be exposed to the open air at night, and it be cold enough, the water will freeze; but if one of these vessels be covered with a pane of glass, or any other body, that water will not freeze, even though the covering body do not rest immediately upon the plate. It is sufficient, continued the author, that the fall of the frigoric be interrupted, no matter whether from an higher or lower distance; and to complete his demonstration, he added the following experiment, which at first aspect seems very cogent, and is certainly very interesting. It is as follows: place in the evening, at a certain distance above a plate filled with water, a funnel, of which the diameter shall be less than that of the plate, you will find the next day a ring of ice formed round the circumference; but all the water situated perpendicularly beneath the funnel will remain fluid.

Usage notes
Neither frigoric nor caloric has been taken seriously since the establishment of the theory of thermodynamics in the nineteenth century.