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290 MINERALOGICAL REMARKS. in the afternoon, accompanied by a new acquaintance, who was to be thy Cicerone, I went to Tallia; he was neither a naturalift nor a philofopher, and got fo beaftly drunk, that.I-was obliged to get rid of him... At Tallia I found another quarry of the white indurated clay ; and in returning I obferved a great quantity of fragments of whitith petrofilex, containing vegetable petrifactions or impreffions, fcattered about on acommon. In the ftreets of Maad lay great heaps of a breccia of petrofilex, fome of which was very pretty, and of a greenifh caft: it is probably ufed here for building. The Baron’s cellar is formed in the white indurated clay. From thence F wentto Tolchva, which is only a ftage diftant. By the road fide, near Lifka, there is a bank of fine white fand,.or a ftone fo friable as to fall readily into fand: from the demand for it, I fuppofe for houfehold purpofes, a great excavation has been formed. It feels very harfh between the fingers ; under the blow-pipe-it at firft crackles, and then {wells up to thrice its bulk, phofphorefeing and producing a white light fcoria that fwims in water, which in a ftronger fire is turned to-a white glafs. This is nothing but a Kind of tufa, formed entirely of the detritus of pumice, or rather of fomething very analogous to it; it contains fome {mall fragments of grey voleanic glafs*. In fome places it is much coarfer, being mixed with * Tufa, Alba heterogenia terrea inequale-granulata afperrima valde friabilis, granulis Obfidiani.nigri & cinerei.rarius infperfis. Tubi ferruminatorii ope crepitat intumefcens ter volumen auget, phofphorefcit, fcoriam aque innatantem præbet, & in igne fortiori vitrum album. an 38
