34 LAWS OF THE MIXTURE 



If these liquids be of equal, or still better, of 

 unequal, specific gravity, they may be, with the aid 

 of some precaution, stratified one above the other. 

 This is, in point of time, the most unfavourable 

 case for the mixture, since proportionally small sur- 

 faces come in contact. But wherever they do come 

 in contact, it is, after a very short time, impossible 

 to detect any limit between them, 



In a cylindrical vessel, containing solution of 

 salt, the saline particles at the surface are attracted 

 and sustained by aqueous particles, which exist at 

 the sides of the saline particles, and from the sur- 

 face downwards. From the surface upwards, the 

 attracting aqueous particles are absent. 



Now it is evident, that when the surface is brought 

 in contact with pure water, a new attraction is added 

 to those previously existing, which acts in an oppo- 

 site direction, namely, the attraction of the aqueous 

 particles floating on the surface for the saline par- 

 ticles, and vice vers& (the attraction of the saline 

 particles to the aqueous particles in contact with 

 them). 



At the place where pure water and brine are in 

 contact, there is thus formed a uniform mixture of 

 the two, which upwards is in contact with pure 

 water, downwards with brine. 



Among these three strata, of which the upper 

 contains no salt, the lower less water, a new division 

 takes place ; the more strongly saline stratum loses 

 salt, the pure water becomes saline, and in this way 



