the Water of the Thermal Spring of Bath. 59 



and ignited. The residue imparted a yellow colour to the 

 blowpipe flame : — Evidencing the presence of soda. 



An alcoholic solution of the residue gave with a concen- 

 trated solution of bichloride of platinum a yellow crystalline 

 precipitate : — Indicating potassa. 



The precipitate which had formed on evaporating for the 

 iodine determination, was treated with hydrochloric acid, the 

 filtrate saturated with ammonia and precipitated by sulphide 

 of ammonium ; this precipitate was re-dissolved in nitro-hy- 

 drochloric acid mixed with chloride of ammonium, and the 

 sesquioxide of iron separated by ammonia. The filtrate, eva- 

 porated and fused with nitrate of potash and carbonate of 

 soda, gave a green mass: — Showing traces of manganese. 



Lithia, alumina, bromine and phosphoric acid were found 

 to be absent. 



In regard to the presence of gases in the water, it was 

 scarcely necessary to test for the presence of free carbonic 

 acid. On mixing a solution of lime with the mineral water a 

 precipitate was formed, which dissolved in an excess of the 

 mineral water. The quantity of free carbonic acid however 

 is not very large ; the water has no reaction on blue vegeta- 

 ble colours ; hydrosulphuric acid is not contained in the water. 

 Acetate of lead gave only a white precipitate of sulphate of 

 lead free from all trace of brown colour, which might indicate 

 the presence of sulphur. 



A large quantity of gas is continually disengaged from the 

 chief spring as well as from the secondary ones. Dr. Dau- 

 beny* paid particular attention to the composition of this gas. 

 He found that it consists principally of nitrogen, together 

 with small quantities of carbonic acid and oxygen. 



He employed a peculiar apparatus, constructed on purpose 

 for these experiments, by which he was enabled to collect the 

 whole of the gases from the principal well, as well as from 

 those adjoining it. The experiments of Daubeny are so nu- 

 merous and accurate as to preclude any other researches on 

 the subject. 



II, Quantitative Analysis, 

 Determination of the Specific Gravity. 



A small bottle, which contained at the temperature of 

 16°'5 C. (60° Fahr.) 10 grms. of distilled water, contained at 

 the same temperature 10*025 grms. of the mineral water; 

 from this the specific gravity of the water is calculated 

 as 1-0025. 



* Vide Memoir mentioned. 



