[387] [In India, one mode of cooling wines, is to suspend the bottle in a thick flannel bag, or folds of blotting-paper, kept constantly wetted, and placed in the sun’s rays, or a current of air, or both; by which means the evaporation, and therewith intense coldness, is produced.] [388] Philosoph. Transact. vol. lxxi. part ii. p. 511. [M. Boutigny’s beautiful experiment of making ice in a red-hot crucible is a striking phænomenon of this kind. It is thus performed:--A deep crucible of platinum is heated to a glowing red heat; liquid sulphurous acid, which has been preserved in the fluid state by a freezing mixture, and some water are then at the same instant poured into the crucible. The rapid evaporation of the volatile sulphurous acid, which boils below the freezing-point of water, produces such an intense degree of cold as to freeze the water, which is then thrown out of the crucible as a solid lump.] [389] Philosoph. Transact. vol. lxxi. part ii. p. 252: the process of making ice in the East Indies; by Robert Barker. [390] [There is no question that this refrigeration is caused by the evaporation of a portion of the water, whereby a very large quantity of heat becomes latent in the vapour. A clear serene sky being necessary for the success of the production of the ice, would tend to show that the further loss of heat by radiation, which always ensues to a great extent at nights, when the sky is clear, is necessary.] [391] ... a number of small, shallow, earthen pans. These are unglazed, scarce a quarter of an inch thick, about an inch and a quarter in depth, and made of an earth so porous, that it was visible from the exterior part of the pans, the water had penetrated the whole substance. [Our ordinary wine-coolers, which consist of extremely porous vessels, act from evaporation. A portion of the water, which is placed in the interior of the cooler, evaporates through its pores, and produces cold by rendering a considerable amount of heat latent.] [392] See the account of Lloyd Williams, in the Universal Magazine, June 1793, p. 410. Thin unglazed vessels are employed at present in Egypt also for cooling water, as we are told in several books of travels. [393] Sympos. vi. 5, p. 690. [394] The word however may be found in Dictionnaire par Richelet, Genève 1680, 4to. [395] J. B. Campegii Libri xxii. de re cibaria, xvi. 9, p. 669.