AVOGADRO

avogadro, amedeo, conte di quaregna (1776-1856), italian physicist, was born at turin on the 9th of june 1776, and died there on the 9th of july 1856. he was for many years professor of higher physics in turin university. he published many physical memoirs on electricity, the dilatation of liquids by heat, specific heats, capillary attraction, atomic volumes &c. as well as a treatise in 4 volumes on _fisica di corpi ponderabili_ (1837-1841). but he is chiefly remembered for his "essai d'une maniere de determiner les masses relatives des molecules elementaires des corps, et les proportions selon lesquelles elles entrent dans les combinaisons" (_journ. de phys._, 1811), in which he enunciated the hypothesis known by his name (avogadro's rule) that under the same conditions of temperature and pressure equal volumes of all gases contain the same number of smallest particles or molecules, whether those particles consist of single atoms or are composed of two or more atoms of the same or different kinds. avoidance (from "avoid," properly to make empty or void, in current usage, to keep away from, to shun; the word "avoid" is adapted from the o. fr. _esvuidier_ or _evider_, to empty out, _voide_, modern _vide_, empty, connected with lat. _vacuus_), the action of making empty, void or null, hence, in law, invalidation, annulment (see confession and avoidance); also the becoming void or vacant, hence in ecclesiastical law a term signifying the vacancy of a benefice--that it is _void_ of an incumbent. in general use, the word means the action of keeping away from anything, shunning or avoiding.