36* Chemical^xamination of the Bath TVatets. 



■united to the pure Ihtie. When I added a fmall quantity of diluted vitriolic acid, the pre- 

 cipitation was rediffolved, and I obferved a feparation of fome air-bubbles. Although the 

 Bath waters contain carbonic acid gas, they yet attradl more air in cooling. This I afcer- 

 tained by expofing a quantity of the water to fome air in a large clofe vefiel, the water having 

 a communicating tube on the outfide. The water in the outfide tube was at firft on a level 

 with the water within, but aficr a litle time the water funk in the outfide tube; proving that 

 the air in the receiver had been abforbed. 



The carbonate of potaih produced a very copious precipitate in each of the waters of the 

 ih^ee baths. 



A folution of pure potafh produces only a flight precipitation in each. A folution of 

 pure ammonii produces alfo in all the waters a weak precipitate. Pure ammonia does not 

 feparate calcareous earth from its folutions. Solution of carbonate of ammonia produces a 

 much greater precipitate in the Hot-bath water than in the other two. In ProfefTor Berg- 

 ■mann's table of affinities we find that lime has a much greater attracSion for the fulphuric 

 and marine acids than the volatile alkali. Upon a folution .of muriate of lime in diftilled 

 water I poured a folution of pure ammonia, and no precipitation enfued ; but on addino- a 

 folution of carbonate of ammonia in diflilled water, a precipitation was plainly perceptible. 

 This laft experiment fhews that a double decompofition took place, in w!)ich the carbonic 

 racidleft the ammonia to unite with the lime, and the muriatic acid left the lime to unite with 

 ,the ammonia. 



Pure ammonia, Tiowever, produces a precipitation in the Bath v^aters, which fhews very 

 clearly that other earths befides lime are contained in them. Now the marine and fulphuric 

 .acids have a lefs attraftion for ammonia than they have for magnefia ; it is therefore not 

 magnefia which is feparated by the pure ammonia. As clay lias a much lefs affinity for tlie 

 marine and fulphuric acids than ammonia, it appears that clay is feparated in the foregoing 

 experiments. I poured fome pure ammonia on a folution of fulphate of alumine, or common 

 alum^ and a copious precipitation enfued. In a former experiment I mentioned ihat a fo- 

 Jution of pure pota{b did not produce fo large a precipitation as the folution of the car- 

 bonate of potafh. The reafon is obvious; for although the pure potafli would feparate the 

 fulpuric and marine acids from lime, yet that lime would be for the moft part rediflblved by 

 the water, and a very fparing precipitation would enfue. This I proved more clearly by 

 adding to the mixture of pure potafh and the Bath waters more diftilled water, which lef- 

 fened the quantity of precipitate, though I could not by thofe means make it entirely difap- 

 pear. This (hews that other earths befides lime are contained in thefe waters. The precipi- 

 tates entirely difippear on the addition of diluted fulphuric acid. 



The oxalic acid produces a copious precipitation when added to the King's-bath and Crofs- 

 bath waters. The Hot-bath waters produce a much greater quantity of precipitate with the 

 tefts for lime than the other two. We have now proved that thefe waters contain a large 

 proportion of lime, and that this lime is combined with fome acid. 



Having feparated by means of a filtre the oxalate of lime which was formed in the fore- 

 going 



