OF SEA- WATER. 235 



aid of the action of alcohol, either as a solvent Or a precipitant, 

 are so great, that analyses executed in this mode can scarcely 

 be perfectly accurate. And as it appears, if the preceding ob- 

 servations are just, that there is no certainty in the conclusion 

 that the products of analysis by evaporation or crystallization 

 are the real ingredients, no peculiar advantage in this respect 

 belongs to this method, and just as much information is ob- 

 tained by discovering the acids and bases which exist in solu- 

 tion, and then inferring, according to the most probable view, 

 what the states of binary combination are in which they exist. 

 This kind of analysis has the advantage, that it can be execu- 

 ted with much more precision than the other : it is liable to 

 fewer sources of error, and, by finding the quantities, not of 

 the compounds, but of the elements, any error that is introdu- 

 ced is discovered, when the binary compounds are inferred. 

 To ensure accuracy, therefore, it was desirable to apply it to 

 the illustration of the present subject, more especially as the 

 preceding analyses, though they do not differ greatly in the 

 results, still, from these difficulties, do not exactly corre- 

 spond. 



Different methods might be employed. The following is 

 , the one I have preferred. 



To a pint of sea-water, reduced by evaporation to nearly 

 one-fourth, at which state of concentration no crystallization 

 nor deposition takes place, muriate of barytes was added as 

 long as any precipitation occurred. By a preliminary trial, it 



Gg 2 was 



tween them ; the quantity of its water of crystallization being considerably 

 less. Its taste is much less disagreeable than that of sulphate of soda or sulphate 

 of magnesia ; it might therefore probably be introduced with advantage as a pur- 

 gative salt, especially as it could be procured at a low price ; and from its 

 composition, it would afford a very good substitute for the aperient mineral 

 waters, which usually owe their activity to sulphate of soda and sulphate of 

 magnesia. 



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