Chemical EKaminatlon of the Bath Waters. 361 



That all this is perfecElly confiftent with fadt, I hope to be able to fliew by experiments I 

 fliall hereafter relate. 



To two ounces of the King's-bath water I added a few drops of a folution of prufliate of 

 potafli, and no change of colour took place, on the addition of one drop of a folution of ful- 

 phate of iron, an evident blue colour appeared. This experiment was made on the Crofs and 

 Hot-bath water with the fame refults. 



The hepatic water, which is compofed of 16 grains of fulphuret of lime, and 10 grains of 

 the acidulous tartarite of potafh, is an excellent tefl: for difcovering metals which are held in 

 folution. Iron precipitated by it is rediflblved by the fulphuric acid. With this teft, I 

 could not perceive the leaft quantity of iron in any of the three waters. 



As iron may be held in a ftate of combination in which it may refill the a<Stion' of the 

 foregoing tefts, I have ufed the following means for afcertaining its prefence. 



In Profeffor Bergmann's table of attraftions, I find that the fulphuric acid has, after the 

 acids of fugar and tartar, the ftrongeft attraction for iron ; I have, therefore, firft added a very 

 fmall quantity of the fulphuric acid, and after a due time for combination, a few drops of the 

 hepatic teft : ftill I could t ot perceive the leaft trace of iron. This experiment was re- 

 peated with other tefts with the fame refults. Had any iron been held in folution by. means 

 of the fulphuric acid, the hepatic teft would moft probably have fliewn it. The fmalleft 

 quantity of that acid was added, that it might not fuperabound with carbonate of potafli. 

 I diminiflied even this quantity : but carbonate of potafli will produce a brown precipitate 

 from the teft, if fulphuric acid has been prefent j but that brown precipitate will not be re- 

 diflblved bv the acid. 



The Bath waters do not produce any change of colour in vegetable tefts, confequently 

 they do not contain any acid or alkali in an uncombined ftate. I added one drop of diluted 

 fulphuric acid to two ounces of each of the Bath waters, which, with that fmall quantity of 

 acid, changed the colour of turnfole. Had there been any difengaged alkali, or earth, it 

 Vould have moft probably deftroyed the efFedls therein produced. 



Diluted fulphuric acid poured into t^o ounces of the King's-bath water, produced a re- 

 paration of minute air-bubbles, which I apprehend are carbonic acid, as lime-water added 

 to another quantity of this water caufed a precipitation. The fame appearances were ob- 

 ferved in the other waters, but their quantities vary confiderably. 



Thefe experiments would lead us to conclude that thefe waters contain carbonic acid 

 gas, either in a difengaged ftate, or united to fqme alkaline bafis. From fome of the fore- 

 going experiments, however, it appears to be in a difengaged ftate, as the tefts did not fliew 

 the prefence of any alkali, and the carbonic gas was too fmall for them to dcted: it. We 

 ihall hereafter fliow that very large quantities of elaftic gafes arife with the waters ; their 

 heat however prevents any large quantity from uniting with them. The carbonic acid has 

 the greatcft attraclion for water, and therefore the other gafes are not combined with it. 



When to the waters of the three baths I poured lime-water, an evident precipitation took 

 place i which precipitation I, of courfe, imagined was owing to the carbonic acid gas being 



united 



