[ ^05 3 
applied, but fllll he funk, though more flowly than 
before ; and it was plain to be obferved, that the 
point between that manner of finking and fwimming 
was balanced with fuch extreme nicety, that the 
fmallefi; addition of cork would determine in favour 
of buoyancy : accordingly half an ounce was added, 
and this weight fupported him in a vibrating flate ; 
but by the fuper-addition of one drachm and two 
fcruples more of cork, he found himfelf very able to 
keep above water, in a living pofition, without any 
help from his art of fwimming, and that it required 
fome fmall pains to immerfe himfelf. It therefore 
refults from this experiment, that twelve ounces, five 
drachms, and two fcruples, or 6100 grains of cork, 
fupported this man in river water ; 6100 grains of 
cork are equal to 163 cubic inches; which appears, 
by a calculate drawn from the fecond of the foregoing 
experiments, to be able to fupport 63 ounces, five 
drachms, and eight grains of lead, which mufi: be, 
therefore, the exadl weight of this man in river water. 
By comparing this calculation with the above experi- 
ment IV. made in the fea water, we fliall find that 
this man weighed 60 ounces, three drachms, and 2 t 
grains; or four pounds, 12 ounces, three drachms, 
and 21 grains, requiring 12 ounces and 21 grains 
of cork to fupport him, in fea water. It mufi: how- 
ever be obferved, as we have already intimated, that 
the fame quantity of cork which fupports a fgt, or 
very plump perfon, in the water, will not fuffice to 
buoy up a lean perfon, although their weights, out of 
the water, be equal. 
VoL. LV. 
P 
XVII. 
