Boiling

(boil'ing,) or EBULLITION. (Chem.) The bubbling up of any fluid. The term is most commonly applied to that bubbling which happens by the application of heat; though that which ensues in other cases, as on the mixture of an acid and carbonate, is sometimes also distinguished by the same name. B., in general, is occasioned by the discharge of an elastic fluid through that which is said to boil; and the appearance is the same whether it be common air, carbonic acid, or steam that pa es through the fluid. The B. of water is occasioned by the lowermost particles being rarefied into vapor on account of the vicinity of the bottom of the containing ve el to fire. Being greatly inferior in sp. gr. to the surrounding fluid on account of this rarefaction, they ascend with great velocity, and, agitating the body of water in their ascent, give it the tumultuous motion called B. Every liquid has a fixed point at which B. commences, and this is called theB. point. Thus water, in ordinary circumstances, begins to boil at the temp. 2120. After a liquid has begun to boil, it will not become hotter; for although a stronger heat makes all liquids boil more rapidly, yet it does not increase their temperature, the additional heat being required to raise the extra quantity of vapor to the same temperature as that of the fluid from which it ascends: since gases and vapors require a greater amount of heat to keep them at a given temperature than fluids or solids. The B. point of ether is 96°, that of alcohol is 176°, that of oil of turpentine is 3160, and that of mercury 6620. [s. 101]