[ _3 
long time pent up in fome Hollow, upon giving it 
Vent, it generally comes out in a pernicious Vapour. 
Experiment XXV. 
It was obfcrved, that the greateft Shocks happened 
to fuch things as flood expofed to Volcano but 
that thofe things which Wete not thus expofed to it, 
received but faint Shocks: A manifeft Sign, that the 
Vibration of the Air had a great Share in the Sho^:ks 
of the Earth : Which Circumftance is taken Notice 
of by with refped'to Mount 
II. An AlfiraB of a Letter from' an 
Gentleman at Naples to hh Friend in Lon- 
don, containing an Account 'of the Eruption 
of Mount Vefuvius, May 1 8. and the fol^ 
lowing DaySy 1737 . 
S I Ri D^tcd Naples, Aug^rSq. ^17 S7. N. S- 
Y OU have laid a very hard Task upon me, to 
fend you an Account of the late Eruption.* * * 
1 was lodged for fome time at Chaja, and after- 
wards at Fontina Medina, in the Face of this fur- 
prifing Neighbour [Mount Vefuvms^, which from 
thence doth not appear to be above two or three 
Miles diftant. 
It gave us Strangers conftant Entertainment, by 
fhewing us what it could do, as well as great Satif- 
faftion to the People of Naples, who, whilft it con- 
i’ nuts burning more or lefs without ceafing, are under 
no 
