264 A GENERAL FORMULA FOR THE 



sentially the same in the subsequent steps of its analysis as a 

 water purely saline ; the precaution only being observed of 

 these principles being removed, and of no new ingredient be- 

 ing introduced by the methods employed. 



The salts usually contained in mineral waters are Carbo- 

 nates, Sulphates, and Muriates, of Lime, of Magnesia and of 

 Soda. In proceeding to the analysis, a general knowledge is 

 of course first to be gained of the probable composition by the 

 application of the usual tests ; the presence of sulphuric and 

 carbonic acids being detected by nitrate of barytes, of muriatic 

 acid by nitrate of silver, of lime by oxalic acid, of magnesia 

 by lime-water or ammonia, and of any alkaline neutral salt by 

 evaporation. It will also be of advantage to obtain the pro- 

 ducts of evaporation, and ascertain their quantities, without 

 any minute attention to precision, the object being merely, by 

 these previous steps, to facilitate the more accurate analy- 

 sis. 



Supposing this to be done, and supposing the composition 

 of the water to be of the most complicated kind, that is, that 

 by the indications from tests, or by evaporation, it has afford- 

 ed carbonates, sulphates, and muriates of lime, magnesia and 

 soda, the following is the general process to be followed to as- 

 certain the ingredients, and their proportions. 



Reduce the water by evaporation, as far as can be done 

 without occasioning any sensible precipitation or crystalliza- 

 tion ; this, by the concentration, rendering the operation of the 

 re-a^ents to be employed more certain and complete. It also 

 removes any free carbonic acid. 



Add to the water thus concentrated a saturated solution of 

 muriate of barytes, as long as any precipitation is produced, 

 taking care to avoid adding an excess. By a previous experiment, 

 let it be ascertained whether this precipitate effervesces or not 



with 



