Oldal 32 [32]
282 MINERALOGICAL REMARKS.
have the fame fhape as the preceding; they are generally a little
bigger and harder, quite opake, of a more or lefs pale or deep brick
colour, marked more or lefs with blackith fpots and ftreaks, and
veined or reticulated like a gland. They fully refemble a marbled
enamel, are generally on one fide more rounded, on the other more
preffed (concavo-convex), and round about edged as a melted fub¬
ftance poured into fmall holes or cavities. Struck with. a fteel they
give more fire than the preceding, and refift the greateft flroke of 2
hammer ; under the blow-pipe they flill more readily than the tranf¬
parent ones change: to a pearl or whitiih colour on the furface,
without great expanfion, and this fcorified furface then very eafily
falls off in fcales. Such are the external qualities of thefe remarkable
ftones, and of the fill more remarkable mowntain-rock in which they
are included. How far the following chemical analyfıs of Mr.
Lowitz, which I give in his own words, can throw light upon their
remarkable properties, I leave to the decifion of others, till I (halt
receive a greater provifion of them (which I am waiting for), and
have it then in my power to fupply the learned of foreign countries,
“ Chemical analyfis of a kind of foffil like Quartz Pebbles, with
the mountain-rock in which they are found.—Thefe roundith
ftones, which are given out for volcanic productions, are chiefly of
the fize of a hazel nut, and have a {moky tran{parent appearance ; but
there are fome which are opake, and of a liver colour {prinkled with
blackifh and reddifh fpots ; they are confiderably hard, fcratch glafs
3 and
30