A frutife of B O D I E S. Chap. 3. 



What we have faid thus in abftract, will (ink more eafily in-' 

 to us if we apply it to fome particular bodies here among us, in 

 which we fee a difference of Rarity and Denfity; as to aire, wa- 

 ter* gold, or the like; and examine if the effects that happen to 

 them, do follow out of this difproportion between fubftance and 

 Quantity. For example,let us conceive that all the Quantity of 

 the world were in one uniform fubftance, then the whole uni- 

 verfe would be in one and the fame degree of Rarity and Derrfi- 

 ty : let that degree, be the degree of water; it will then follow, 

 that in what part foever there happeneth to be a change from, 

 this degree, that part will not have that proportion of quantity 

 to its fubftance, which the quantity of the whole world had to 

 the prefuppofcd uniform fubftance. But if it happeneth to have 

 the degree of rarity which is in the aire, it will then have more 

 quantity in proportion to its fubftance, then would he due unto 

 it according to the prefuppofed proportion of the quantity of . 

 the univcrle to the forefaid uniform fubftance; which in this cafe 

 is as it were the ftandard to try all other proportions by. And 

 contrariwise , if it happeneth to have the degree of Denfity 

 which is found in earth or in gold; then it will have lefTc quan- 

 tity in proportion to its fubftance, then would be due unto it ac- 

 cording to the forefaid proportion, or common ftandard. 



Now to proceed from hence t with examining the effects 

 which refult out of this compounding of Quantity with fub- 

 ftance, we may firft confider, that the definitions which Ari- 

 ftotlc hath given us of Rarity and Denfity, are the fa me we 

 drive at : he telleth us, that that body is rare whofe quantity is 

 more, and its fubftance leflc; that, contrariwifedenfe, where the 

 fubftance is more and the quantity leflc. Now if we look into 

 the proprieties of the bodies we have named, or of any others, 

 we (hall fee them all follow clearly out of thcfe definitions. For 

 firft, that one is more diffufed, another more compacted ; fuch 

 diffusion and companion feem to be the very natures of RarL 

 ty *id Denfity, fuppofing them to be fuch as we have defined 

 them to be ; feeing that, fubftance is more diffufed by having 

 more parts, or 6y being in more parts; and is more compacted 

 by the contrary. And then, that rare bodies are more divifible 

 then denfeones, you fee is coincident into the fame conceit with 

 their diffufion and compaction. And from hence again ic fol- 



loweth, 



