UNIVERSALLY DIFFUSED. 29 



When we add alcohol to the solution of a salt in 

 water, we observe, that now the salt separates from fromits S 

 the liquid in the form of crystals, doubtless only alcohol* , 7 

 because, by the addition of another chemical force, 

 the amount of attraction between the particles of 

 the salt and those of the water has been altered. 



The aqueous particles, which were combined with 

 the saline particles, manifest an attraction for the 

 particles of alcohol ; and as the latter have no affi- 

 nity, or only a very feeble affinity, for those of the 

 salt, the attraction of the saline particles for each 

 other is strengthened. This attraction was present 

 in equal force before the addition of the alcohol, 

 but the resistance which opposed their union (the 

 chemical attraction for them of the aqueous parti- 

 cles) was more powerful. The alcohol was not the 

 cause of the separation. The cause of the separa- 

 tion of the salt from the liquid, its crystallization, 

 is at all times the force of cohesion ; and by the 

 alcohol the cause which opposed its manifestation 

 was removed. 



The affinity of potash for sulphuric acid is known, O f sulphate 

 and sulphate of potash readily dissolves in water, byc^ic 

 If we add, to a saturated solution of that salt, an po 

 equal volume of aqua potassse of sp. g. 1*4, there 

 is immediately formed a crystalline precipitate of 

 sulphate of potash, and the sulphuric acid is sepa- 

 rated in this form from the water. 



In these cases the chemical effect (the separa- 

 tion) depends on the presence of a certain quantity 



