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202 Jrgillaceous Genus. ift Family. Tripoli. Hill 67. Colour, generally pale yellowiih grey, or ifa- bella, or pale ochre yellow, or pale or reddiih brown, or greyiih, reddilh, or yellowiih white, ieldom greeniih white. It is found in a loofe earthy, but oftener in an indurated, confiftence. *' Luftre, o. Tranfparency, commonlyo; yet fbat of the harder forts, if wet, often 1. " Fraflure, earthy; in the harder forts inclining to the flat conchoidal, fometimes verging to the flaty. Fragments, o, 1, •’ Hardnefs from 4 to 7. Sp. gr. ofthe harder fort, after fufflcient abiorption of water, 2,529*. Feels, harfh, dry, and frequently duft'y; ilightly/ or fcarce at all, adherent to the tongue; takes* no poliih from the nail; does not ftain the fin- gers. In water the fofter forts foon crumble into pow- der; the harder iorts imbibe it, but crumble flowly. It docs not effervefce uüth acids, unlefs mixed vvith marl, as it frequently is. It frequently reddens when heated. Mr. Ilaafle found thisearthtocontain 0,90 fflex 0,07 argill, and 0,03 iron. ’ Le&e^O 6 ^?™ 511 ’ Wh ° fe fp ' ^ 1 determined » was that in Another