OF SOLIDS AND LIQUIDS. 239 



dense ; or in other words, the rise or fall of 

 bodies in different moveable media, whether 

 solid, liquid, or gaseous, altogether depends on 

 the quantity of matter which those bodies seve- 

 rally contain, with relation to the quantities of 

 matter which they displace. 



It is owing to this relation which exists be- 

 tween the subject which fills, and the matter 

 of the medium which has been dispossessed ; 

 that bodies of unequal bulks, have unequal 

 weights, in the same medium ; and, on the con- 

 trary, that bodies of the same bulks, have un^ 

 equal weights, in media of different densities ; 

 the increment of weight will be in proportion 

 to the decrement in the density of the medium; 

 and in proportion to the increment in the den*- 

 sity of the medium, an increment in the levity 

 of the body will ensue. The facts which 

 prove the truths of these propositions are so 

 universal and common, that it may, perhaps, 

 be considered superfluous in me to detail 

 them. There is not a brave sailor, who as- 

 sists at the capstern, in heaving up an anchor 

 from the bottom of the sea,.but knows, that the 

 force, or purchase, which is necessary to raise 

 the anchor from the surface of the sea to the 

 bows of the ship, is much greater than it is from 

 the bottom of the sea to the surface of it; the hir 

 crease of weight, or pressure downwards, 

 which the anchor has acquired in the air, above 



