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QMS vesicles of water, which we call a steam. Violent 

 heats lifts up great quantities of water, which the air can- 

 not buoy up : and this we call boiling. 2. If the.se va- 

 pours be intercepted in their ascent, by any dense body,, 

 especially if it be cold ; they are thereby reduced into 

 drop?, Uke those of rain. 3. In frosty weather the 

 vapours rise but a little above the water, and there hang 

 or glide on. If the weather be cold ; after a little as- 

 ceut, they fail again into the water. But in a warm still 

 air, they ascend swiftly and largely, and mount up, till 

 they are out of sight. 



To explain this a little farther, it may he observed, 

 that the parts of water being so small and moveable, are 

 easily separated from one another. And when they are 

 so divided into small parcels, as to become about eight 

 hundred times lighter than common water, they are as 

 light as the air, and will by every successive degree of 

 separation, rise in the air in proportion to their lightness, 

 the heavier air forcing the rarified fluid to ascend into 

 the atmosphere, till it finds a place in equilibrium among 

 bodies of equal lightness to itself. This separation, or 

 Comminution (ir 1 may so call it), of Water into small par- 

 cels, may be performed either by collision against harder 

 and more compact bodies, or by heat. The first we 

 often see performed at the bottom of cascades, where 

 the water that falls but a few fathoms, shnll rise in a 

 mist from the bottom where it is broke; and there are 

 instances of clouds rising from the fail of waters, whieii 

 may be seen five miles of. Collision will therefore ex- 

 cite vapours : but what is more constantly producing 

 this effect in every part of the universe, is heat : whether 

 from the sun, which is always busy this way, or from ar- 

 tificial ignition, or that generally invisible elemental fire, 

 which is distributed through all matter, It is not neces- 

 sary for us to consider in this case, any other than the 

 divisibility of water, and the insinuating and dispersive 

 qualities of fire. Fire we see separates more or less the 

 parts of all bodies, whether fluid or solid, and makes 

 them rise in. the air; and it does no more to water ; it 



