an Eruption of Mount Vefuvius. 45 
wide, and feven or eight feet deep. They were often hid 
from the fight by a quantity of fcoria that had formed 
a cruft over them, and the lava having been conveyed in 
a covered way for fome yards, came out frefii again into 
an open channel. After an eruption I have walked in 
fome of thofe fubterraneous or covered galleries which 
were exceedingly curious, the fides, top and bottom, be- 
ing worn perfectly fmooth and even in raoft parts by 
the violence of the currents of the red-hot lavas, which 
they had conveyed for many weeks fuccefiively; in 
others, the lava had incrufted the fides of thofe channels 
with fome very extraordinary J cor ire: beautifully rami- 
fied white falts u> , in the form of dropping ftalactites, 
were alfo attached to many parts of the cieling of thofe 
galleries. It is imagined here, that the falts of Vefuvius 
are chiefly ammoniac, though often tinged with green, 
deep, or pale yellow, by the vapour of various minerals. 
In the month of May laft, there was a confiderable 
eruption of Mount Vefuvius, when I pafled a night on 
the mountain in the company of one of my country- 
men, as eager as myfelf in the purfuit of this branch o! 
natural hiftory (i K 
(c) I fent a large fpecimen of this curious volcanic production to the Britifh 
Mufeum laft year. 
(d) Mr. bowdleRj of Bath. 
We 
