z6z Analyfis of the Air. 
know not whether the common praftice of 
laying a bar of iron on a veffel, be a good 
prefervacive againft the ill effefts of lightning 
on liquors. I fhould think that the covering 
a veflel with a large cloth dipped in a ftrong 
brine, would be a better prefervative 5 for 
fairs are known to be ftrong attraders of 
fulphur. 
The certain death which comes on the 
explofion of Mines, feems to be effeded in 
the fame manner : For tho' at firft there is 
a great expanfion of the air, which muft 
dilate the lungs, yet that air is no fooner 
filled with fuliginous vapours, but a good 
deal of its elafticity is immediately deftroy’d : 
As in the cafe of burning Matches in Expe- 
riment 103. the heat of the flame at firft ex- 
panded the air $ but notwithstanding the 
flame continued burning, it immediately 
contracted, and loft much of its elafticity, 
as foon as fome quantity of fulphureous 
fleams afcended in it. 
Which fleams have doubtlefs the fame 
effeft on the air, in the lungs of animals 
held over them 5 as in the Grotto di cani 9 
or when a clofe room is filled with them, 
where they certainly fuffocate. 
It 
