Avogadro, Amadeo

Amadeo (1776-1856), a noted professor of physics at Turin. Remembered as the discoverer of what is known as Avogadro's Law: "Equal volumes of all gases, under the same conditions as to temperature and pressure, contain the same number of molecules."

Avoirdupois (French, to have weight), a system of weights based on a pound of sixteen ounces or 7,000 Troy grains. It was introduced into England from Bayonne, France, about 1300 A. D. It has been inherited by the colonies of England. It is used chiefly for the weighing of coarse commodities. The principal denominations are the ounce, pound, hundredweight, and ton,--the latter consisting of twenty hundredweight. See Ton