A popular guide to minerals : with chapters on the Bement Collection of minerals in the American Museum of Natural History, and the development of mineralogy . ime were happy in being ignorantof their own ignorance. Henkel and Pott, in the period lapsing from the seventeenthto the eighteenth century, were perhaps most active, and their chem-ical researches helped sensibly to introduce more exact definitionsof mineral species. Heat at various intensities was a common agent for chemicalinvestigation. In this way the combined water of gypsum wasdetected; Boyle had subjected gems to the ordeal of
A popular guide to minerals : with chapters on the Bement Collection of minerals in the American Museum of Natural History, and the development of mineralogy . ime were happy in being ignorantof their own ignorance. Henkel and Pott, in the period lapsing from the seventeenthto the eighteenth century, were perhaps most active, and their chem-ical researches helped sensibly to introduce more exact definitionsof mineral species. Heat at various intensities was a common agent for chemicalinvestigation. In this way the combined water of gypsum wasdetected; Boyle had subjected gems to the ordeal of the furnace,and averred that from most of the transparent minerals he hadobtained a pungent vapor. Henkel divided stones or minerals into four classes, accordingto their behavior when exposed to heat: 1. As they withstood fire. 2. As they were hardened by fire. 3. As they underwent pulverization upon rubbingafter heating. 4. As they melted in fire. ^H iif /^^^\M^H ^^B ^^^^ _sAf aaMS^^^M ^H^B^ ^^1 ^ ^^ ^^^?^^-- -*-^^ g^^: ^^^^^k H 1 iHcu { 1 ^^^^^ ^^^^M ^^^^^^H TOPAZ (in Albite) Tamagami Yama, Japan Bement Collection, American Museum of Natural History. PHENACITE Takowaja, Ural Colection, American Museum of Natural History ..•§? DEVELOPMENT OF MINERALOGY 223 In the first class he arranged the diamond, ruby, beryl, sap-phire, topaz, chrysolite, and silica; in the second, clay, serpentine, fullers earth, and other clays; in the third, limestone, ala-baster, sinter; in the fourth, sulphur, garnet. Oriental hyacinth,malachite, and Icelandic agate, viz., obsidian. The fundamental constituents of stones were argillaceous sub-stances, calcareous or metallic, and subsidiary to these, the salty,oleaginous, metallic, and saline-sulphurous. These distinctions werefar removed from that definiteness of chemical composition whichcharacterizes mineralogy, but still they contained a rude approxima-tion of a general scheme not altogether irrelevant to the facts ofnature. In the rea
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmineral, bookyear1912
