The Edinburgh new dispensatory : containing I. The elements of pharmaceutical chemistry. II. The materia medica ... III. The pharmaceutical preparations and compositions. Including translations of the Edinburgh pharmacopoeia published in 1809 ... Illustrated and explained in the language, and according to the principles of modern chemistry ... / by Andrew Duncan jun. ... [etc.].

  • Duncan, Andrew, Jun., 1773-1832.
Date:
1811
Catalogue details

Licence: Public Domain Mark

Credit: The Edinburgh new dispensatory : containing I. The elements of pharmaceutical chemistry. II. The materia medica ... III. The pharmaceutical preparations and compositions. Including translations of the Edinburgh pharmacopoeia published in 1809 ... Illustrated and explained in the language, and according to the principles of modern chemistry ... / by Andrew Duncan jun. ... [etc.]. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    29/904 (page 7)
    CALORIC. 4ft. Heat, in common language, is a term employed to express both a certain sensation, and the cause producing that sensation. In philosophical language, it is now confined to the sensation, and the term Caloric has been adopted to express the cause. 50. The particles of caloric repel each other : it is therefore disposed to fly off in every direction from a body in which it is accumulated, or to pass off by radiation. 51. Caloric is attracted by all other bodies. It has therefore an irresistible tendency so to distribute itself as to produce an universal equilibrium of temperature, or to pass from bodies in which it is accumulated, into bodies in which it is deficient, un^ til the attraction of each for caloric, and the repulsive force (50) of the caloric contained in each become equal to each other. 52. Caloric is radiated most slowly by polished metallic sur- faces, and most quickly by rough blackened surfaces. 53. Radiated caloric is admitted most readily by rough black- ened surfaces, and most difficultly by polished metallic surfaces. 54. Radiated caloric is transmitted with the velocity of light; and is, in like manner, reflected and refracted. 55. But the passage of caloric through most bodies is im- mensely slower than radiated caloric. 56. When caloric moves through bodies with this diminished velocity, it is said to be conducts^ by them. Metals are the best conductors ; then stones, glass, dried wood. Spongy bodies, in general, are bad conductors. Fluids also conduct caloric ; but as they admit of intestine motion among their particles, they carry it more frequently than they conduct it. 57. Temperature is that state of any body, by which it excites the sensation ol heat or of cold, and produces the other effects which depend on the excess or deficiency of caloric. 58. The most general effect of caloric is expansiofi; the only real exception to this law being the contraction of water^ from the lowest temperature at which it can remain fluid, to 42© 5/ F. This expansion either consists, a, in a simple increase of volume ; or b. it produces a change of form in the substance heated. a, a, from solid to fluid ; fusion^ liquefaction. b. b. from solid or fluid to vapour; vaporization, 59. Bodies expand gradually, and at all temperatures, as long as they undergo no other change. 60. Bodies difl'er very much in the degree of gradual ex- pansion (58. a) which equal increments of temperature produce in them. Gases are more expansible than fluids, fluids than