APPENDIX. 289 
mixture, thro* the InterfHces of the Clouds, 
make like the two Airs in the Glafs, a more 
violent EfFervefcence, than if thofe Airs had 
without the Intervention of Clouds more 
gradually intermixed, by the conftant regular 
Afcent of the warmer fulphureous Vapours 
from the Earth, and Defcent of the cold (erene 
Air from above. And tho’ there was no lumi- 
nous Flafli of Light in the Glafles, yet when 
fuch fudden Eifervefcence arifes, among a vaft 
Quantity of fuch Vapours, in the open Ex- 
panfe of Air, it may not improbably acquire 
fo rapid a Velocity, as to kindle the fulphu- 
reous Vapours, and thereby become luminous. 
13. And fince from the Etfeds chat Light- 
ening is obferved to have on the Lungs of 
Animals which it kills, by deftroying the Air*s 
Elafticity in them, as alfo from its burfting 
Windows outwards, by deftroying the Air s 
Elafticity on the Outfide of thofe Windows 5 
fince it is hence probable that its fulphureous 
Fumes do deftroy a great Quantity of the Air’s 
Elafticity wherever it pafles ; it fliould therefore 
caufe the greateft Commotions and Concufti- 
ons in the Air, when the Air rufhes into thofe 
thus evacuated Places : Which it muft necef- 
'farily do with great Velocity. Dr, Papin has 
U calculated 
