510 Ingredients cf [Book VIL 



2. The vitriolic, nitrous, and muriatic acids. One 

 or other of thefe acids exift in almoft all mineral wa- 

 ters : they are ufually combined with earthy or me- 

 tallic bales, but fometimes, efpecially the vitriolic, 

 exift in a feparate flate, To as to occafion a fenfible 

 acidity. 



3. An alkaline fait is found in many waters in 

 Hungary, Tripoli, and other countries. It is ufually 

 the foflil alkali which is combined with fixed air in 

 the Seltzer waters, and with the mineral acids in a 

 great variety of others. The vegetable and volatile 

 alkalies rarely or never are ingredients in mineral 

 waters. 



4. Neutral falts are not uncommon in fprings. 

 Common fait, nitre, and vitriolated magnefia, are the 

 the moft ufual ; the latter is very abundant in a fpring 

 at Epfom in Surrey, and has therefore obtained the 

 name of Epfom fait. Sal ammoniac has alfo been 

 found in fome fprings in the neighbourhood of volca- 

 noes and burning coal mines. 



5. Earthy fubftances. Of thefe the calcareous is 

 fometimes found to abound fo much, as to be depo- 

 fited on fuch fubftances as it comes in contact with, 

 and occafion petrifaction. In this cafe the fufpenfion 

 of the calcareous earth feems to depend on the prc- 

 fence of fixed air, which, making its efcape when the 

 water ifTues into the open air, fuffers the calcareous 

 earth to feparate. The calcareous earth of waters is 

 very commonly united with the vitriolic acid, and ex- 

 ills in the form of gypfum, which is only foluble in 

 water in the proportion of one part in feven or eight 

 hundred. Calcareous nitre and muriated calcareous 

 earth are alto occanonally found in fprings. 



6. Sulphur. Many waters feem by their offenfive 

 fmell to contain' fulphur, though very few of them, 



upon 



