Projekt: Bestände der Universitätsbibliothek Freiberg
LDP: UB Freiberg Druckschriften
Ausgabe
4. ed., considerably augmented by Robert Allan
Strukturtyp
Monographie
Parlamentsperiode
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Wahlperiode
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Titel
Combustible Minerals; Those of which the base is sulphur or carbon. It includes substances of the most opposite external characters; both the hardest and the softest in nature
COMBUSTIBLE MINERALS; Those of which the base is sulphur or carbon. It includes sub stances of the most opposite external characters; both the hardest and the softest in nature. SULPHUR. Natiirlicher Sdnvefel, AV. Soufre, II. Prismatic Sulphur, M. Sp. Gr. 1-9—2-1. H. = 1-5—2-5. Colour when pure, citron-yellow; from accidental admixture sometimes red, brown, yellowish-grey, and even green. Pri mary a four-sided pyramid, with equal and similar scalene trian gular planes, and of which the common base is rhombic. It oc curs massive, disseminated, investing other minerals, and crys tallized in the form of an acute four-sided pyramid, cither perfect or variously modified ; cleavage imperfect and interrupted ; frac ture conchoidal, uneven in the impure varieties ; lustre shining and resinous, varying from transparent to translucent on tl> e edges; very brittle. It burns readily with a lambent blue, or white flame, according to the low or high degree of temperature, emitting at the same time a pungent smell of sulphureous acid, and fuses into a brown liquid. It acquires resinous electricity by friction. $ () Fig- 1, the primary pyramid. Fig. 2. the same elongated. Fig- the same, having its summits replaced. Fig. 4 : in this two opposite solid angles of the octahedron are replaced by rhombic planes. Fig- 6 : this the edges of the base of the pyramid are deeply replaced by quad' rangular planes. In fig. C, the summits of the primary are replaced by four triangular planes, forming a low pyramid on each.