Properties : Calcium oxid occurs as hard, white or grayish-white masses, which, in contact with the air. gradually attract moisture and carbon dioxid and fall to a white powder; it is odorless and has a caustic taste. Calcium oxid is converted into calcium hydroxid on the addition of water and this is slightly soluble in cold water (1:760), less soluble in hot water and practically insoluble in alcohol.

Milk of lime is calcium hydroxid mixed with water in the proportion of 1 part of lime to 4 of water.

Action and Uses: Lime as calcium hydroxid is a fairly active germicide. It will neutralize acids, forming soluble salts of calcium.

On account of its cheapness lime is much used as a disinfectant. In the form of milk of lime or whitewash, it is a serviceable application to privies or to the infected walls of rooms. It is especially useful for the disinfection of excreta. Freshly prepared milk of lime should be added in volume equal to that of the material to be disinfected, the mass thoroughly mixed and allowed to stand for two hours before disposal.