I 
( n ) 
fore it Will then be fpecifically lighter than common 
Water, whofc Ipecifick Gravity is to that of Air, as 
850 to I ; then if the E)enfity of the Aura, or Spi- 
fhl.Tit!’? be fuppofed 9 Times Icfs 
vity of the Shell, and its Contents will be to that 
RMhh?^’ R°°r ° ’ therefore fuch an aqueous 
“ Equilibrium in 
Air, .whole Denfity is to the Denfity of that in 
Which It began to rife, as 8fo to 94/ nearly. But 
« appears by Experiments, that Air rarefied^ by an 
Heat which makes a Retort red hot. is onlv 
creafed m Bulk, or dilated 3 Times; by the Hwt of 
boiling Water only jf or near two Tteds; and by 
V the Humane Body (fuch as will raift 
Vapours plentifully ) only ^ or about f. I own my 
Objedion may be anfwered, by fuppofing the Sphe- 
rule of Water to be more encreafed in Diameter, as 
for Example zo Times ; becaufe then if it be filled 
with Air only i rarer than common Air, it will be 
SrSiig?"’ “p"' «f "«”s . co«i- 
. To give this Solution all its Force, let us expreft 
It in Numbers. Let A and W f.) reprifent 
jBu^ = J, 
A. o 
Bu/A=j, 
W, o 
Bulk=Scoo^‘s'‘^=lBulk^9kt 
w(^ - - 
C X 
a Par* 
