Analysis of the Hot Spr'nig'! at Bath. 35 T 



a dark brown colour, evidently derived from its action upon 

 carbonaceous matter. This experiment did not appear con- 

 clusive, as two causes of error might have existed, — a small 

 quantity of alcohol was probably decomposed by the action 

 of the salts upon it, or some of the conferva which is found in 

 the water might have escaped notice previous to evapora- 

 tion. I had recourse, therefore, to other means. Mr. 

 Kirwan, in his Treatise on the Analysis of Mineral Waters, 

 gives a method for ascertaining the presence and quantity of 

 extractive matter proposed by Westrumb, which consists in 

 precipitating the muriatic salts by nitrate of lead, and after- 

 wards the extractive matter by nitrate of silver. It is Imposr 

 sible to conceive any method more completely fallacious 

 than this ; for extractive matter is as readily precipitated by 

 nitrate of lead as by nitrate of silver; and although muriate 

 of soda is decomposed by nitrate of lead, muriate of lead 

 being a salt of considerable solubility, the subsequent addi- 

 tion of nitrate of silver would decompose it, and afford a 

 precipitate consisting of muriate of silver without any ex- 

 tractive matter. 



The power of sulphuric acid to detect carbonaceous matter 

 is extremely great : -j-J— dth of a grain of sugar was dissolved 

 in four ounces of water; to this solution about one ounce 

 of sulphuric acid was added : it was then boiled till nearly 

 the whole of the water was evaporated, and tlic acid had ac- 

 quired a verv distinct brown colour. 



The followinc: experiment was now made : 



(.r) A quantity (jf sulphuric acid was added to one quart 

 of the water perfectTv transparent, and free from heteroirc- 

 neous matter. The mixture was evaooratcd ncarlv lo drv- 

 ness in a retort, and the arid remained pcrfectlv colour- 

 less. The water, therefore, contains no carbonaceous 

 matter. 



The substances contained in the water, as shown by the 

 foregoing experiments, are ; carbonate of lime, oxide of iron, 

 ■?nlphatc of lime, muriate of soda, and sulpliatc of soda. 'I"hc 

 pre-ence of ilicse compound; has been universally allowed ; 

 but that silica is containrd in the water, was discovered bv 

 Z 3 Dr. 



