A Treat >fe of B O D I E S. Chap. 1 1. 



be made in half the time, a quarter of the motion in a quarter 

 of the time, and fo without end, as farre as you can divide. But 

 this is demonftrativcly imnoflfible, fnh hence it is demonstrated 

 that a moveable coming from reft , muft of necefficy pafle 

 through all degrees of tardity; and therefore by thedemonftra- 

 tion cued out of GalUeus, we may take a 'part in which this 

 gravity cannot move its "body in a proportionate part of time, ' 

 through a proportionate part of the medium. 

 1 2. Butbccaufe in natural! Theorems, experiences are naturally 



required ; let us fee whether nature giveth us any teftimony o 

 this verity. To that purpofe we may confider a plummet hang, 

 ed in a final! ftringfroma beam, which being lifted up gently 

 on the one fide at the extent of the firing, and permitted to 

 fall merely by the power of gravity, it will afcend very near as 

 high on the contrary fide, as the place it was held in from 

 whence it fell. In this experiment we may note two thingsrthe 

 firft, that if gravity be a quality, it worketh againft its own 

 nature in lifting up the plummet, feeing its nature is oncly to 

 carry it down. For though it may be anfwered, that it is no 

 the gravity but another quality called vis imprejfa which car- 

 rieth it up: ncvertheleiTe it cannot be denied, but that gravity is 

 either the immediate or at leaft the mediate caufe which maketi 

 this vis impreffa :' the effect whereof being contrary to th 

 nature of gravity, it is abfurd to make gravity the caufe of. it 

 that is, the caufe of an eflence, whofe nature is contrary to it 

 own. And the fame argument will proceed though you pu 

 not vis imfrejfa, but fuppofe fome other thing to be the caufe 

 of the plummets remounting, as long as gravity is faid to be a 

 quality : for ftill gravity muft be the caufe of an efFe& con 

 trary to its own inclination, by fetting on foot the immediat 

 caufe to produce it. 



The lecond thing we are to note in this experiment of th 

 plummets afcent is, that if gravity be a quality, there muft bx 

 as much refiftancc to its going up, as there was force to its co 

 mingdown. Therefore there muft be twice as much force tc 

 make it afcend, as there was to make it dcfcend : that is to fay 

 there muft be twice as much force as the naturall force of th 

 gravity is: for there muft be once as much to equalize the refi 

 ftance of the gravity; and then another time as much, to carr 



