[ 178 ] 
portion to the Quantity of Brimftone burnt') ; And 
this plainly happens by fome of the Effluvia-, or 
little Parts of the Sulphur, attracting fome of the 
Particles of the il^ir, fo as to make an unelaftic Com- 
pound, that precipitates into the Water. If the 
Elafticity of the Air is quite loft when the Repulfion 
of its Particles is taken off, or fufficiently counter- 
acted, it muft follow, that its Elafticity depends upon 
Repulfton : And that this is often the Cafe, appears 
by a great Number of Dr. Hales h Experiments, of 
which I will mention but a few. The DoCtor took 
a Cubic Inch of Mutton-Bone, and having put it 
into his Gun-B^irrel Retort, he diftill’d out of it two 
or three hundred Cubic Inches of Air into a large glafs 
Bottle, the Weight of which Air, together with the 
Afhes of the Bone left, weighed as much as the whole 
Quantity of Bone did at firft. Now the Air had been 
confin'd in that Bone,, together with many fulphureous 
Particles, in fuch manner,, that the mutual Attraction 
of the Sulphur and the Air had alternately deftroy'd 
each other’s repulfive Force, and brought thofe Sub- 
ftances into a little Compafs; but the Fire in the 
Diftillation feparated them from each other, fo as 
to reftore them, in a great mealure, to their ufual 
Elafticity. This appear’d by bringing a Candle near, 
the Mouth of the Bottle that held this reviv’d Air 5 
for every time the Candle was brought near, the Air 
took Fire, and flafh’d out of the Bottle with a ful- 
phureous Smell. The Air may be confolidated in 
many hard Bodies, fo as to be there quite void of 
Elafticity, and there do the Office of a Cement, till 
by the ACUon of Fire, or fome particular Fermen- 
ictions, it is again reftor’d to its perfectly elaftic State. 
This 
