f 575 ) 
Weight 6f the Fluid, when it ceafes to be fudain’d in 
the faid Fluid : contrary to Monfieur Ldhnitz's Princi- 
ple. 
Scholium. 
If a Cloud (by any Caufe whatfoever) becomes fpe- 
cifically heavier chan that Parc of the Air in which ic 
fwims, the Excels of its Gravity above an equal Bulk 
■of Air will make it delcend, and accelerate its Motion 
downwards; and then indeed ic will lofe of its Weight 
by the Refiftance of the Medium, till it comes to an 
uniform (or lenfibly uniform) Motion : but all the 
Weight that ic will lole will only be the Excefs of its 
Gravity above that of the Air ; for with the reft of its 
Weight it will ftill make up part of the Weight of the Air. 
E>efeYiment I. Figure 6. 
Having with a Weight in the Scale C of the Balance 
B counterpois’d the long Glafs of Water E /, with 
a Horfe-Hair I let down the leaden Weight fV into 
the Water, which from F6 arofe up to EH; and 
therefore the V'/ater became heavier by the Weight of 
a Bulk of Water equal to ^he Lead. Having with ano- 
ther Weight in C made up the Counterpoife to the 
whole, with fine Sciftars I cut the T hread of the Plum- 
met ; and all the while the Plummet was falling, the 
Water defcended rather than rofe ; and when the Lead 
was at the bottom the Water overpois’d, becaufe it had 
then added to it all the Excefs of Weight of the Lead 
above an equal Bulk of Water, which by Experiment 
is about n of its Weight. Had Meftieurs Reaumur 
and Ramazzini trfd the bxperiment thus, the Succefs 
had been the fame ; but Mr. Ramazzini (as I under flood 
from a Gentleman who was prefent) tried it in the fol- 
lowing Manner, as I have fince done. 
T 1 1 t L 
