SYMBOL, that which specially distin guishes one regarded in a particular character, or as occupying a particular office, and fulfilling its duties; a figure marking the individuality of some being or thing; as, a trident is the symbol of Neptune. In chemistry, an abbreviation of the name of an elementary body: thus C for carbon, H, hydrodgen, P, phosphor ous, etc. When two or more of the names begin with the same letter, a second let ter is added to the symbol of one of these elements for the sake of distinc tion: thus Hg=hydrargy rum (mercury), Pb=plumbum (lead), etc. The symbol also represents a defi nite quantity of the element: thus H always=one part by weight of hydro den, parts of mercury. In the ology, a primitive name for the Creed, often occurring in the works of the early fathers. Also sometimes applied to the elements in the Sacrament of the Euch arist.
Mathematical symbols are of four kinds: (1) Those which stand for quantities; such as letters standing for numbers, time, space, or any of the geometrical magnitudes. (2) Those of relation, as the signs, =, > , • etc., which indicate respectively, the rela
tions of equality, inequality, proportion, etc. (3) Those of abbreviation, as :., for "hence," • .•, for "because"; exponents and coefficients are likewise symbols of abbreviation, the symbol consisting in the manner of writing these numbers. (4) Symbols of operation, or those employed to denote an operation to be performed, or a process to be followed; such are the symbols of algebra and the differential and integral calculus, etc., which do not come under the preceding heads. Those of the third class are generally regarded as symbols of operation. Symbols of op eration are of two kinds: (1) Those which indicate invariable processes, and are, in all cases, susceptible of uniform interpretations. This kind includes most of what are usually called the signs of algebra, as +, —, X, ÷, J . (2) Those which indicate general methods of pro ceeding without reference to the nature of the quantity to be operated on.