8|4 An Analysis of Sea-water ; 



binary combinations will be those of sulphuric acid with lime, 

 and of muriatic acid with soda. And on the same principle, we 

 may infer that, in a dilute sohition containing these elements, 

 the combinations will, from the influence of the power the re- 

 verse of cohesion, that of the solvent action of the liquid, be 

 those of sulphuric acid with soda, and muriatic acid with lime. 

 In a concentrated solution, containing muriatic and sulphuric 

 acids, soda and magnesia, sulphate of magnesia and muriate of 

 soda are formed ; and, on the same principle, in a dilute solu- 

 tion, there must exist sulphate of soda and muriate of magnesia. 



This principle, if just, is an important one, as enal)ling us to 

 determine the state of binary combinations in a saline liquor. I 

 add, therefore, one other illustration of the reasoning on which 

 it rests. 



Suppose that in a compound saline solution, that is, one con- 

 taining more than one acid and one base, the acid and the base 

 which have the strongest attraction, are those which are most 

 soluble, or form the most soluble compound ; the solvent power 

 of the liquid operating at the same time, will concur with this, 

 and favour their combination ; and any other acid and base like- 

 wise present, will of course, at the same time, combine. But 

 supjjose the more powerful attraction to belong to those which 

 form an insoluble compound, the solvent power counteracts this, 

 and prevents the combination. And the more this power is in- 

 creased, which is done by increasing the quantity of the solvent, 

 the more will this be counteracted. The reverse combinations will 

 therefore be established by tlie operation of the opposite affini- 

 ties. Hence, generally speaking, in a dilute solution, the binary 

 combinations must be those which form the most soluble com- 

 pounds, and very powerful attractions would be required to coun- 

 teract this. 



Applying this principle to the composition of sea-water, or 

 rather to the (juestion with regard to the sulphate of soda and 

 sulpiiate of magnesia, it is obvious, that the former is to be con- 

 sidered as the original ingredient, and the latter as a product of 

 the evaporation ; for muriate of magnesia and sulphate of soda 

 are, on the whole, more soluble in water than muriate of soda 

 and sulphate of magnesia. On the same principle it follows, still 

 more unequivocally, that the lime exists in the state of muriate 

 of lime, with a portion of sulphate of soda equivalent to the quan- 

 tity of sulphate of lime which the evaporation affords. The salts, 

 therefore, really existing in sea-water, are muriate of soda, mu- 

 riate of magnesia, muriate of lime, and sulphate of soda. The 

 quantity of muriate of soda is less than what is obtained by eva- 

 poration, for a port'dn of it is formed by the decompositions 

 ivhich occur ; the quantity of muriate of magnesia is larger, as 



a portion 



