WAT
WAT ( 475 )
tions are with great difficulty feparated. This*lfo produces no fenfible change in water.
4 - Carbonic Acid . Almoft all natural waterscontain a portion of this galeous acid, but whichVaries extremely from r isv or lefs °f the bulkof the water, to an equal built. When thequantity is about T V, and uncombined with anyother bale, it gives an agreeable pungency tothe tafte, and a fparkling appearance.
Carbonic acid is found, either totally unac-companied with any other fubllance withwhich it has any affinity, or totally unitedwith an alkaline, - earthy, or metallic balls ; ormore commonly partly combined, and partly inexcefs (that is to fay, more than fufficient tofaturate the bafe) and by its excefs renderingthe bafe ftnuble, or, if this excefs is ftill greater,imparting to the water the fame pungency as ifit were entirely unaccompanied by any otherbody, lhe only carbonats hitherto found inmineral waters are the carbonats of.foda, mag-nefia, lime, and iron. Of thefe the two formerare foluble in water, without any fuch excefsof acid as to render the water acidulous, butnot the two latter.
5. Sulphuretted Hydrogen. A confiderablenumber of waters contain a very notable quan-tity of this gas, which gives its peculiar fetidfmell, and naufeous, fomewhat fweetifh tafte.In general the fulphuretted hydrogen is uncom-bined with any bafe, but there are fome waters,particularly fome of the hot fprings, which,along with this fubftance, contain foda, withwhich it doubtlefs combines, and this compoundoften contains an excefs of fulphur,which it depo-sits in a fmal 1 quantity. Sulphuretted hydrogenis incompatible with no other gas but oxygen.
6 . Sulphureous Add is found in fome fprings,though rarely, aitd hitherto has been only metwith in the neighbourhood of volcanoes.
7. Sulphuric Acid is a very common ingre-dient in waters, but never uncombined, and itgives a fenfible acidukmfnefs, only when the faitof which it forms a conftituent part naturallycxifts with excefs of acid, fuch as alum andfulphat of iron. 'The other combinations ofthis acid, and in which it is fully neutralized,are fuipbats of foda, lime, and magnefia. Ithas only been fount! united with potafh whenthey both form conftituents of alum.
8. Muriatic Arid has only been found com-bined and in compleat faturation. 1 he muri-ats of foda, magnefia, and lime, are very fre-quent, the muriats of alumine, iron, manganefe,and potafh, are rarely found, and the latter iseven doubtful.
9. Boracic Acid has been found uncombinedin a lake in Tufcany.
10. Nitric Acid , united with potafh and pro-bably- with, other bafes, is found in thole fpringsthat come in contact with the native nitre withwhich Hungary and fome other countriesabound.
11. Soda is the alkali of by far the moft fre-quent occurrence in mineral waters. It is fome-times uncombined or-only united to carbonicacid, fo as to give a fenfible alkalefcency to thetafte, and to chemical tefts, and caufes the Waterto lather by agitation. Thefe alkaline watersare generally hot.
Soda is alfo found united with fulphurettedhydrogen, with fulphuric acid, as Glauber’sfait, and with muriatic acid, as common fait.Both thefe falts are very frequent in waters,and the latter often in very large quantity.
12. Potajh has been extracted, as it is fnid,from one mineral water, and as late refearcheshave Thewn it to be contained in fome minerals,it may probably be found in other waters.
13. Ammonia has been detected by Mr. Ca-vendifh in a fpring near London .
14. Lime is never found uncombined inwater, but is contained in fmall quantity inalmoft every natural water, united with fulphu-ric acid as felenite, and is fcarcely lefs frequentdiffolved in water by means of carbonic acid.Muriat of lime is alfo not uncommon.
15. Magnefia is found in the fame combina-tions as lime, but not quite fo frequently.
16. Alumine is not unfrequent in mineralwaters. Often it is merely lufpcnded in ex-tremely fine divifion, but it has ^ alfo beendetected in union with the fulphuric and mu-riatic acids.
17. Si/ex. This earth was firft detected byDr. Black in the water of the celebrated boilingfprings of Iceland . As thefe waters containan excefs of foda, and as fiiex is rendered folu-ble in water by means of alkali, it was rationallyconjectured that this, together with the greatheat to which the waiter is expofed, caufcd thefolution. The, fame earth has however beenfincc detected by Dr. Gibbs, in Bath water,which is not alkaline.
18. Iron is a frequent ingredient in mineralfprings, in fmall quantity, but fufficient 'to givea very fenfible chalybeate tafte and fmell. Itis generally held in folution by the carbonicacid, and is then always accompanied by car-bonat ofiime, and often of magnefia ; but fome-tinies it is in the form of fulphat.
All the chalybeate waters depofit oxvd of
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