THEORY OF SOLUTION AND CRYSTALLISATION. 263 



Admitting the views expressed in this paper, we have only to 

 consider the process by which a super-saturated solution is prepared, 

 to perceive that the dissolved salt must have been at the outset 

 partly severed from union with the water. Upon cooling to a 

 lower temperature, all the time in a state of repose, it is conceivable 

 that these dissociated water and salt molecules may not come 

 together again, at any rate in their usual order and proportion, so 

 that a condition of strain exists throughout the whole mass. If 

 this is relieved at one point a re-arrangement occurs, which quickly 

 extends to other parts of the liquid, and the result is the production 

 of that hydrate which is most stable at the temperature of the 

 experiment. 



