g8 ESSAYS anp OBSERVATIONS 
vain attempt, to aflign any meafure of the im- 
preffions; becaufe, it follows clearly from the 
demonftrations of Sir If/aac Newton*, that 
the body would go on for ever. And furely, 
it requires not much abftract reafoning to 
prove, that meer zertia, without the help 
of fome active power, like gravity, or the 
attraction of cohefion, could ‘never totally 
confume any motion, or reduce a body from 
a ftate of motion to a ftate of abfolute reft. 
Yet, after all, as every one has heard, that 
the refiftance of a perfect and incompreflible 
fluid, was in the duplicate ratio of the velo- 
cities; this was foundation enough for a lover: 
of peace, to affert roundly, that the impref- 
fions'made in a fluid, were in that ratio like- 
wife. Greater f{tretches might well be per- 
mitted for the accomplifhment of fo defirable 
an end, asa compleat union and harmony a- 
mongft philofophers. 
WHEN one body ftrikes upon another with 
a great velocity, the parts immediately im- 
pelled are fometimes broken off or driven 
away beyond the reach of attraction, before 
they have time to draw the other parts after 
them with any obfervable force; and the 
force 
Princip. Lib. If. Prop. v. et cor. 
