This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1840 Excerpt: ...melts, but without raising the temperature of the water above 32; so that water is a compound of ice and caloric. On the contrary, when a liquid is converted into a solid, a quantity of caloric leaves it without any diminution of temperature. Water at the temperature of 32 must part with 140 of caloric before it freezes. The slowness with which water freezes, or ice thaws, is a consequence of the time required to give out or absorb 140 of latent heat. A considerable degree of cold is often felt during a thaw, because the ice in its transition from a solid to a liquid state, absorbs sensible heat from the atmosphere and other bodies, and by rendering it latent, maintains them at the temperature of 32 while melting. According to the same principle, vapour is a combination of caloric with a liquid. By the continued application of heat, liquids are converted into vapour or steam, which is invisible and elastic like common air. Under the ordinary pressure of the atmosphere, that is, when the barometer stands at 30 inches, water acquires a constant accession of heat till its temperature rises to 212 of Fahrenheit; after that it ceases to show any increase in heat, but when it has absorbed an additional 1000 of caloric it is converted into steam. Consequently, about 1000 of latent heat exists in steam without raising its temperature, and steam at 212 must part with the same quantity of latent caloric when condensed into water. Water boils at different temperatures under different degrees of pressure. It boils at a lower temperature on the top of a mountain than in the plain below, because the weight of the atmosphere is less at the higher station. There is no limit to the temperature to which water might be raised; it might even be made red-hot, could a vessel be ...