[ 99 ] 
thefe being united, formed one float (marked B) that 
they might the nearer refemble the texture of the 
cork jacket. A vefi'el of fea water taken up near the 
North Foreland being then provided, the float was 
found to fupport in it a leaden medallion weighing 
1048 grains. When it had continued in the fea 
water for 48 hours, it exadly fupported 1024 grains, 
having, by being in the fait water, for that fpace of 
time, loft 24 grains of its buoyant power. 
From this experiment we learn, that the fait water 
iniinuates more into the fubflance of cork than frefli 
water doth, wliich may perhaps be attributed to its 
oilynefs, oil being, as is very well known, more 
fubtil and penetrating, than water ; it could not 
therefoie be expecfted that the cork fliould therein 
letain its force fo vigoroufly, for lb long a time, as 
it doth in the frefli river water ; and, on weigh- 
ing, it was found to lofe ^ of its buoyancy in 48 
hours. 
But then we are further to obferve from the above, 
that the lea water fupports a greater weight, and gives 
more buoyancy to the cork float than frelh water, in 
the proportion of 353 to 359 ; for a float weighing 44 
grains, lupporting 353 grains of lead in frefli water, 
buoyed up 359 lead in the lea water, being 
more by fix grains. And it is to be noted, that the 
fea water taken up at the North Foreland is not fo 
much irnpregnated v/ith tiie marine pidnciples, as that 
which is taken up at a greater diflance from frelh 
water rivers, which decreales in its buoyancy in 
m 
* 
Vid.^ Macellinus. Pliny (Lib. xxxi. Cap. 7.) P. 
(Lett. Millionaires, Odav. Edit.) jtnd Dr Hales 
O 2 
Bour,(i-cs 
O 
proper- 
