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I 9° Argillaceous Genus. rnily; but, iffufibility be an effential property of lithomarga, this earth does not belong to it; for neither of the fpecimens, 1080, 1081, Lefke O. are fufible in a heat of 150°, but harden into a brittle blackilli mafs, and feemed to me to con- tain charcoal. Thefpecimen 1080 pofleffes, in- deed, all the other charaders of the harder li- thomargas; but the fpecimen Lefke O. 1079, feels dry, and fcarcely adheres to the tongue; fo that Iconfider it rather as an indurated clay. A lithomarga phofphorefcing when fcraped, of a pearl colour, and fomewhat femitranfparent, was difcovered in the Hartz by Baron Trebra. I Chy. An. 1784. Lafius, Hartz 313. Is it not rather a mixture of lithomarga and bole? 3d Family. Bole. Colour, dark Ifabella yellow, firongly inclining to brown, or pale liver brown, fometimes dotted or variegated with black fpots, or dentritical figures, or reddilli brown, feldom flefii red. Luftre, o. Tranfparency, fcarcely 1. Fradure, conchoidai. Fragments, 2. Acquires a polifh by light fridionj fcarcely adheres to the tongue; feels greafy. Flardnefs, 4. Sp. gr. from 1,4 to 2. It immediately crumbles in water into powder, and not into pieces. Mr. Bergman comprehends this earth under the head of Lithomarga, and gives the foliowing ac- count of Lemnian earth, which is one of the mo.ft notcd