ALUMINOUS CHALYBEATE SPRING IN I. OF WIGHT. 95 



some less direct method ; and the expedient which appeared 

 the most appropriate was that of inferring the point in ques- 

 tion from a reference to the quantities of acids as estimated 

 in the preceding section. Thus as it was obvious that, what- 

 ever the case might be with regard to sulphate of soda, the 

 presence of muriate of soda in the water was unquestionable; 

 and as the whole quantity of muriatic acid discovered in the 

 water (§XIII, 2), corresponded to a quantity of muriate of 

 soda which fell far short of the sum total of alkaline salts, I 

 naturally inferred, that the whole of the muriatic acid was 

 united with soda, and that the water must also contain a 

 quantity of sulphate of soda sufficient to complete the 20 

 grains of alkaline salts, which the experiments just related 

 had shown to exist in each pint of the water. 



7. Since therefore the whole of the muriate of soda, as 

 was before computed (§XIII, 2), amounted only to 4gvains 

 in a pint, the quantity of crystallized sulphate of soda con- 

 tained in each pint of the water will be 16 grains. 



Sect. XV. Comparison of the quantities of Acid actually 

 obtained from the water by precipitation, with the quan- 

 tities inferred from the precipitation of the basis, 



1. It appears evident, from all that precedes, that the Quantities of 

 only acids contained in the water are the sulphuric and mu- acW obtained 

 riatic. The whole of the muriatic acid having been shown ticif compared 

 to exist in the form of muriate of soda, nothing farther re- with thatiu * 

 inains to be said on this head. But it will be curious to t h Q bases, 

 examine how far the total amount of sulphuric acid, obtained 



from a portion of the water, would coincide with that which 

 might be inferred from the quantities of bases, with which it 

 was combined. This inquiry will give rise to the statement 

 of certain results respecting the proportions of acid and base 

 in some of the salts concerned, and the precipitates obtained 

 from their decomposition, which, from their general import 

 in chemical analysis, appear to deserve some attention. 



2. It was ascertained by a direct experiment (§ XIII, I) 

 that the whole of the sulphuric acid, contained in a pint of 

 the water, formed, when precipitated by a bary tic salt, a 

 quantity of sulphate ofbarytes, which, after being ignited, 

 weighed 74 grains. 



I.shali 



