The Edinburgh new dispensatory ... Illustrated and explained in the language and according to the principles of modern chemistry. With ... tables and several copper-plates, explaining the new system of chemical characters.

  • Duncan, Andrew, Jun., 1773-1832.
Date:
1803
Catalogue details

Licence: Public Domain Mark

Credit: The Edinburgh new dispensatory ... Illustrated and explained in the language and according to the principles of modern chemistry. With ... tables and several copper-plates, explaining the new system of chemical characters. Source: Wellcome Collection.

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

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    35. Radiated Caloric is tranfmitted with the velocity of light $ &ftd, like it, it is refle&ed and refracted. 36. Caloric is attracted by all other bodies. It has therefore &n irrefiftible tendency fo to diftfibute itfelf as to produce an uni- verfal equilibrium of temperature, or to pafs from bodies in which it is accumulated, into bodies in which it is deficient, until the at- traction of each for calorip, and the repulfive force (34.) of the caloric contained in each become equal to each other. 37. Caloric, communicated in this way, is faid to be conducted.; and the conducing power of different bodies feems to be inversely as their affinity for caloric. Metals are the belt conductors; then (tones, glafs, dried wood. Spongy bodies, in general, are bad conductors. Fluids alfo conduCt caloric ; but as they admit of in- teftine motion among their particles, they carry it more frequent- ly than they condu& it. 38. The general effeCts of the abftraCtion of caloric, are dimi-. tuition of volume, condenfation, diminution of temperature, and fenfatiorvof cold. It alfo influences affinity, and, in general, re* fcards folution. The abltraCtion of caloric never can be total; and the attempts to Calculate the thermometrical point at which it would take place have hitherto been fruitlefs. 39. The means employed to increafe temperature are, the rays of the fun, collected by means of a concave mirror, of double con- vex lens> ele&ricity, friCtion, percuffion, collifion, condenfation, nhd combuftion. Caloric is abltraCted by rarefaction, evaporation, and liqnefaCtion. 40. Temperature is eftimated relatively by our fenfations, and abfolutdy by means of various inftruments. The thermometer indicates temperature, by the expanflon which a certain bulk of fluid undergoes from the addition of caloric, and by the condenfa- tion produced by its abftraCtion. Mercury, from the uniformity €>f its expanflon, forms the moft accurate thermometer; but for temperatures in which mercury would freeze, alcohol mull be employed. Air is fometimes ufed to ffiew very fmall variations of temperature. The pyrometer of Wedgewood, which is em- ployed for meafdring Very high temperatures, depends upon the permanent and uniform contraction of pure clay at thefe tempera- tures. Light. 4t. Light emanates in every direction from vifible bodies. 42 It moves in ftrdight lines, with a velocity equal to 200,000 feiiles in a fecond. 43. Its gravity is not appretiable. 44. When a ray of light paffies very near a folid body, it is in- &e&ed towards it. 45. Whefc