17 



ways* That they Lave such a motion, plainly appears 

 from their dissolving hard bodies. Put a piece of cop* 

 per into a glass of aquafortis, and there is iirst an efFer* 

 vescence, then the copper diminishes, and at last disap- 

 pears. And what strong waters are with regard to 

 metals, other liquids are to other substances. Each of 

 them is a dissolvent, more or less, according to its com- 

 ponent particles. Now it is plain that dissolution 

 supposes motion, and is the effect of it. There is 

 .therefore in all liquors an intestine motion from which 

 this effect results. 



Water is a transparent liquid, capable of heat and 

 cold, and of being rarified into vapour. But it is not 

 capable of being condensed, by any method yet known* 

 It is of itself without smell or taste, and liable to putre- 

 faction. It is heavier by many degrees than air,, and in- 

 sinuates where .air cjumot enter. These properties do 

 unquestionably depend on the figure and texture of its 

 parts. But these, after our most curious researches, it 

 is not possible to know with certainty. Dr. Boerhaave 

 says, no one ever yet saw a drop of pure water. It is 

 never pure from salts. For ail water contains air, atid 

 all air contains salts. 



The particles of water are generally allowed to be 

 round. This figure indeed is probably inferred from 

 its fluidity. Allowing then the particles of it to be 

 round, fluidity must be an essential property of all 

 quantities and assemblages of it. For take any mass 

 of round bodies, (bullets for instance, pebbles, or the 

 like) they will not cohere or rest by one another with- 

 out force, but will flow on every side, till they meet 

 %vith such resistance from external bodies, or rather in- 

 ternal gravitation, as shall prevent further motion. 



The particles of water are unalterable, for passing in- 

 to so many bodies, and through such alternate extremes 

 of heat and cold, if they had not preserved their es* 

 sential properties constantly, moisture, since the begin- 

 ning of the world, must have very sensibly diminished. 

 But seeing no such deficiency appears, and that springs, 

 rains, and rivers, are as abundant now as they anciently 



