,n 'A Trf4tife of BODIES. Chnp. n. 



rr.cnt of the variety of circmnftances, as to be able to determine 

 when there is abfolutely more caufc of weight, and when kiTe. 

 And as we find not weight enough in cither fide of thefe oppo- 

 fne circumftances to turn the fcales in our difcourfc, fo likcwifc 

 we find the fame indifference in experience it felfrfor the weights 

 \vc ufe do weigh equally in mifty weather and in clear: and yet 

 in rigour of dilcourfe, we cannot doubt but that in truth they . 

 t!o not gravitate or weigh fo much ( though the difference be 

 imperceptible tofcnfe} when the aire is thick and foggy > as 

 when it is pure and rarified: which thicknefTeof the medium, 

 when icarriyeth to a very notable dcgree,as for example to wa- 

 ter, maketh then a great difference of a heavic bodies gravita- 

 tion in it; and accordingly we fee a great difference between 

 heavie bodies descending in water and in aire; though between 

 two kinds of aire none is to be oblerved, their difference is fo 

 fmall in refpcl of the dcnfity of the body that defcendeth in 

 them. And therefore, feeing that an afftired and certain diffe- 

 rence in circumffances maketh no fenfible inequality in the cf- 

 fe&j we cannot expect any from fuch circumitanccs as we may 

 reafonably doubt whether there be any inequality among them 

 or no. 



Befides that; if in any of the propofed cafes a heavy body 



fhould gravitate more, and be heavier onetime then another; 



ycc by weighing it, we could'not difcern it; fince that the coun- 



terpoife ( which is to determine its weight ) muft likcwife be in 



the fame proportion heavier then it was, And bcfulcs weighing, 



no other means remaineth todifcover its greater gravitation,but 



to compare it to time in itsdefccntrand I believe that in all fuch 



diftances as we can try it in, its inequalities \villbenowhic 



Icfle difficult to be obfervcd that way, then any other. 



5. Laflly, to bend our dilcourfe particularly to that inftancc of 



The rc-ion why tne obje-tion ; where it is conceived that if gravity or de- 



Ifeickbody * fcending downwards of bodies proceeded from atomes ftriking 



doth no^hm- ^ V p On t hem as they move downwards ; it would follow, that a 



of that which /rone or other denfe body lying under fheltcr of a thick, hard, 



K under it. an( j ^penetrable adamantine rock, would have no impulft 



downwards, and confequently would not weigh there. We 



may note, that no body whatfbevcr compacted by phyficall 



caufcs and agents , can be Ib denfe and i/r.poroux, but tli.it 



fuch 



