274 A GENERAL FORMULA FOR THE 



in the muriate of soda obtained, or the amount of the deficit 

 being added to that quantity, the real quantity of Muriatic 

 Acid will be obtained *. 



There is one deficiency, however, in this method. If any 

 error has been introduced in any previous step of the analysis, 

 either in the estimation of the bases or of the acids, this 

 error will be concealed by the kind of compensation that is 

 made for it, by thus adapting the proportion of muriatic acid, 

 to the results such as they are obtained ; and at the same time, 

 an incorrect estimate will be made of the quantity of muriatic 

 acid itself. When any error, therefore, can be supposed to ex- 

 ist, or, independent of this, to ensure perfect accuracy, it may 

 be proper to estimate directly the quantity of muriatic acid in 

 a given portion of the water, by abstracting any sulphuric or 

 carbonic acid by nitrate of barytes, and then precipitating the 

 muriatic acid by nitrate of silver or nitrate of lead. The real 

 quantity will thus be determined with perfect precision, and 

 the result will form a check on the other steps of the analysis, 

 as it will lead to the detection of any error in the estimate of 

 the other ingredients ; for when the quantity is thus found, the 

 quantities of these must bear that proportion to it which will 

 correspond with the state of neutralization. 



Thus, by these methods, the different acids, and the differ- 

 ent bases are discovered, and their quantities determined. To 

 complete the analysis, it remains to infer the state of combina- 

 tion in which they exist. It will probably be admitted, that 

 this must be done on a different principle from that on which 

 the composition of mineral waters has hitherto been inferred. 

 The compounds which may be obtained by direct analysis, 



cannot 



* The analysis of sea-water in a preceding paper, will afford an illustration 

 of this (page 237.) 



