BINARY THEORY

in chemistry, a hypothesis regarding the construction of salts, first proposed by Davy. The a umption is that all salts contain merely two substances, or two elements; a basis, or electropositive, which may be a metal, or a radical and an acid, or electro positive element, or radical. Or, in simpler terms, that all salts contain merely two substances, which either are both simple, or of which one is simple, and the other a compound, playing the part of a simple body. The old illustration is common salt, or chloride of sodium, which is constructed of the metal sodium and the non-metal, chlorine, and is at a glance seen to be a binary (or double) compound. In like manner, fluor-spar, or the fluoride of calcium, consists of the metal calcium and the non-metal fluorine,,