phosphorescence (1 Ergebnisse)

(Paris, L'Imprimerie Royale, 1732). 4to. Without wrappers. Extracted from "Mémoires de l'Academie des Sciences. Année 1730". Pp. 524-535. First appearance of Dufay's importent work on phosphorescence."Chemists had long been acquainted with a fes minerals like the Bologna stone (BaS) and Balduin's hermetic phosphor (plain CaS) that glowed after exposure to light. Greatmystery surrunded those expensive and supposedly rare substances. Dufay detested mysteries and held as a guiding principle that a given physical property, however bizarre, must be assumed characteristic of a large class of bodies, not of isolated species. He found that almost everything except metals and very hard gems could be made phosphorescent: he depressed the phosphor market by describing his procedure: and he became sensitive to the endless small variations in the physical properties of bodies. 'How many things behave that seemed similar, and how many varieties there are in effects that seemed identical." (Heilbron "Electricity in the 17 & 18 Centuries", p. 251).Another paper attached to Dufay's paper is Charles Pitot "Reflexions sur le Mouvement des Eaux". Pp. 536-544 a. 1 folded engraved plate. (Poggendorff II:p. 459).Partington "A History of Chemistry" III, p.66.