Mixture, and its Effects. 97 



matter, but only between its minute and invisi- 

 ble particles. Thus, if we place a piece of salt 

 as near as possible to water, it will not unite 

 with it, unless it is in contact. 



2. The minuteness of the particles into which 

 bodies are divided by mixture is beyond the 

 power of imagination. We may form some sort 

 of notion pf this minuteness, by dissolving a 

 small grain of the size of a pin's head of nitrat 

 of silver in a quart of river water. The water is 

 tinged with a milky colour ; every particle of 

 water has therefore a sensible quantity of silver 

 in it. If to this mixture we add the solution of 

 muriate of soda, or common sea salt (a transpa- 

 rent fluid), we shall see the little grain of silver, 

 which was dispersed through the whole of the 

 water, separating in a subtile powder, and falling 

 to the bottom. The saline liquor added has no 

 disposition to disturb the transparency of the 

 water, when it contains none of the silver; yet 

 it is no sooner added to this solution of silver 

 than the whole of the liquor becomes muddy, 

 and every drop appears to have contained parti- 

 cles of the metal. The nitrat of silver is a com- 

 bination of the nitric acid and silver. The par- 

 ticles of silver were actually divided from each 

 other by the nitric acid before put into water. 

 That the whiteness is occasioned by the com- 

 mon salt, of which there is a little in most 

 river water, is plain by adding some of i to 



VOL. II. K 



