of some Calamines. 7 Electrical Calamine. The Abbd Hauy has considered this kind as .differing from the other calamines only in the circumstance of being in distinct crystals; but it has already appeared, in the instance of the Derbyshire calamine, that all crystals of calamine are not electric by heat, and hence, that it is not merely to being in this state that this species owes the above quality. And the following expe riments, on some crystals of electric calamine from Regbania in Hungary, can leave na doubt of its being a combination of calx of zinc with quartz; since the quantity of quartz obtained, and the perfect regularity and transparency of these crystals, make it impossible to suppose it a foreign admixture in them. a ‘ 2 3-4>5 g rs - of these Regbania crystals, displaced 6.8 grs. of distilled water, from a stopple-bottle, at the temperature of 64* Fahrenheit; their specific gravity is therefore = 3.434. The form of these crystals is represented in the annexed Figure. , ac = go. , ae — 150°. be = n 5 °. , ' J . . *- :* f • c cl = 130°. ' ' They were not scratched by a pin; a knife marked them.