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8 Mr. Smithson’s chemical Analysis b. One of these crystals, exposed to the flame of the blow pipe, decrepitated and became opaque, and shone with a green light, but seemed totally infusible. Borax and microcosmic salt dissolved these crystals, without any effervescence, producing -clear colourless glasses.. Carbonate of soda had little if any action'on them. ; . h.\ ’ •• c. According to Mr. Pelletier’s experiments* on the cala- ’ mine of Fribourg in Brisgaw, which is undoubtedly of this species, its composition is, " Quartz - - - 0.50 Calx of zinc - - - °-38 Water - 0.12 ;; 1.00. >The experiments on the Regbania crystals have had different results; but, though made on much smaller quantities,-'they will perhaps not be found, on repetition, less in conformity with nature. - '-' i 23.45 g rs - heated red hot in a covered crucible, decrepitated a little, and became opaque, and lost 1.05 gr. but did not fall to powder or grow friable. It was found, that this matter was not in the least deprived oflits electrical quality by being ignited; and hence, while hot, the fragments of these decrepitated crys tals clung together, and' to the crucible.^ d. 22.2 grs. of these decrepitated Crystals, = 23.24 grs. of the original crystals, in a state of impalpable powder, being digested over a spirit-lamp with diluted vitriolic acid, showed no effervescence; and, after some time - , the mixture became a jelly. Exhaled to dryness, and ignited slightly, to expel the superflu ous vitriolic acid, the mass weighe - d 37.5 grs. * l Journal de Physique, 'Fome’XX. p. 424.