[ 40 ] 
my whole attention, with refpedl to natural hiftoiy, 
was confined to mount Vefuvius, and the wonder- 
ful phaenomena attending a burning mountain ; but, 
in proportion as I began to perceive the evident 
marks of the fame operation having been carried 
on in the different parts above defcribed, and 
likewife in Sicily, in a greater degree, I looked upon 
mount Vefuvius only as a fpot on which nature was 
at prefent adive, and thought myfelf fortunate in 
having an opportunity of feeing the manner in which 
one of her great operations (an operation, I believe, 
much lefs out of her common courfe than is gene- 
rally imagined) was effeded. 
Such remarks as I have made on the eruptions of 
mount Vefuvius, during my refidence at Naples, 
have been tranfmitted to the Royal Society, who have 
done them more honour than they deferved. Many 
more might be made upon this adive volcano, by a 
perfon who had leifure, a previous knowledge of the 
natural hiftory of the earth, a knov/ledge of che- 
miflry, and was pradifed in phyfical experiments, 
particularly thofe of eledricity. I am convinced that 
the fmoke of volcanos contains always a portion of 
eledrical matter, which is manifeft at the time of 
great eruptions, as is mentioned in my account of the 
great eruption of Vefuvius in 1767. The peafants 
in the neighbourhood of my villa, fituated at the foot 
of Vefuvius, have aflured me, that, during the erup- 
tion lafi: mentioned, they were more alarmed by the 
lightening and balls of fire that fell about them with 
a crackling noife, than by the lava and the ufual 
attendants of an eruption. I find in all the accounts 
of great eruptions mention made of this fort of 
lightening. 
