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Shorl. 269 know to which of them the few analyfcs we havc of Ihorls lhould be particularly applied. Mr. Ber^man, in his Treatife on Gems, teils us that fhorl contains a larger proportion of filex than garnet does (and in garnet the filiceous is the moft copious ingredient); next to that the argil- larerms- and next to that the calcareous is the moft prevalent. In black Ihorls, he teils us, iron is in the proportion of 20 per ct. however, as he men- tions yellow, brown, and green Ihorls, it is uncer- tain to which of them this gradation of ingredients lhould be attributed. Mr. Wiegleb, indeed, feems to have analyzed the genuine fhorl of which we here treat; yet his account differs in many circumftances from that of all other chemifts; for, in the firft place, he found that unlefs the union of itsconftituent parts were weakened by calcination with an alkali, Ipi- rit of nitre, even by long digellion, could diffolve no part of it Änd again he teils us, it contains nocalx, but only 0,3416 filex, 0,4125 argill, o,ao iron, 0,0541 manganefe f. Mr. Chaptal, on the other hand, relates, that he found, in the black prifmatic lhorl of Gevau- dan, 0,52 filex, 0,37 argill, 0,05 calx, 0,03 nianganefe, and 0,03 of iron. 2 Chaptal, p. 123. Mr. Saufiure alfo informs us, that the Ihorls he examined were in great meafure foluble m nitrous and all the mineral acids without any previous Operation, and contained both magneüa * 1 Chym. An. 1585. p.*246. t 1 Crell Beytragc.4 Stuck, p. 33.