‎HAUY (R.J. Abbé)‎
‎Traité des caractères physiques des pierres précieuses pour servir à leur détermination lorsqu'elles ont été taillées -- EDITION ORIGINALE -- BEL EXEMPLAIRE‎

‎P., Courcier, 1817, un volume in 8 relié en pleine basane racinée, dos orné de fers dorés, (reliure de l'époque), (petite épidermure sur le second plat de la reliure), 22pp., 253pp., 3 planches dépliantes‎

Reference : 2606

‎---- EDITION ORIGINALE ---- BEL EXEMPLAIRE ---- EX-LIBRIS Charles MONIER DE LA SIZERANNE ---- "In 1795 Hauy began teaching courses in physics and mineralogy at the Ecole des Mines and became a member of the new founded Institut National des Sciences et des Arts... After the death of Dolomieu, He became in 1802 professor of mineralogy at the Muséeum d'Histoire Naturelle where he enlarged the mineral collection. In 1809 he was also appointed to the newly created chair of mineralogy at the Sorbonne. In his stubborn opposition to the notions of indefinite compounds, mixed crystals, isomorphism, and polymorphism Hauy showed that, despite his mild and pliable character, he was adamant when his deepest convictions were at stake... After establishing the foundation of his crystal theory, Hauy applied it to mineralogical classification. Both Romé de L'Isle and Hauy held that the characteristic form of the constituent molecule of a compound is due to the forms, the definite proportions, and the definite arrangement of the constituent elementary particles. That is, before Proust they proposed a priori the chemical law of fixed proportions. For Hauy the mineral species was defined by a geometrical type and a chemical type ; the crystallographic molecule and the chemical molecule were identical. Molecules of different species, except those of the isometric or regular system, have different forms and different composition. These ideas enabled Hauy to unite in one species minerals hitherto considered different, such as beryl and emerald, and to divide groups that had been considered varieties of the same species, such as zeolites. Hauy's survey to the results of crystallography and chemical analysis in relation to the classification of mineral gave a detailed exposition of the successes and difficulties his method encountered. Chemical composition decided the four traditional classes in mineralogy and the orders and genera ; the form of the constituent molecule determined the species. Only with the formes limites were the physical properties and/or the chemical composition indispensable for definition of the species...". (DSB VI pp. 178/183)**2606/ARM2A‎