Oldal 26 [26]
OCR
276 MINERALOGICAL REMARKS. It is of an ath colour *, here and there variegated with red, very fragile, and the texture like a congeries of fmall tunicated ill-fhaped beads, of a rather greafy luftre. It greatly imtumefces under the blow-pipe, even to thrice its bulk, and forms a white fcoria; but it only flightly phofphorefces, and forms no gelly with nitrous acid, which are two of the principal characters of Zeolite. In fome parts. the little globules, which are formed of different coats, contain a nucleus of Obfidian; the thin coats are eafily detached. Of thefe nuclei I picked up a great many at the foot of the bank, moftly of the fize of a pea, but fome of the fize of a bean: they are more orlefs angular, but never cryftallized as Mr. Fichtel informs us. I have feen his pretended cryftals, and can affure my readers, that none but thofe who are blinded by mineralogical hypothefes, and call in conceding fancy inftead of fevere judgment to be their eounfellors, can think them fuch. Thefe globules likewife fwell under the blow-pipe, and form a whitith glafs,, Mr. Fichtel, who, I know, is very expert with the blow-pipe, fays, in his, Mineralog. Aufsat. page 277, that he could only melt the Lipary Obfidian ; and thofe of Hekla, Tranfylvania and Hungary, he found to be altogether infufible. This greatly furprifes me; and the infufibility of this foflil is aflerted by him likewife in his account of the Carpathian mountains, page 580. I have tried the {mall grains, and fragments of pieces two or three * Cinerens durus fragilis un€tuofo-nitens, textura crafle granulata ex globulis parvis angulofis tunicatis. Tubi Ferruminatorii ope ter volumen auget & fcoriam albam cum. parum phofphorefcentiæ præbet, pounds 24
