28 Dr. Thomson's Analysis of a Specimen of Water [July, 



of Cambridge, who informed me that it was taken at the spot by 

 Mr. Crystal. I was obliged to leave London shortly after I got 

 the specimen, and was not again in possession of a laboratory 

 till last winter, when I subjected it to the requisite trials to ascer- 

 tain its composition. 



I. Properties of the Water. 



The water was transparent, but there was a slight black 

 flocky sediment at the bottom. It had the smell of sulphuretted 

 hydrogen gas ; but the smell was not much stronger than that of 

 St. Bernard's Well, near Edinburgh. Its taste was strongly 

 saline ; but without the bitter impression yielded by sea water. 



The specific gravity at 60° was 1-0331 . 



II. Action of Reagents. 



1 . Muriate of barytes threw down a copious white precipitate 

 which was not redissolved by nitric acid. Indicating the pre- 

 sence of sulphuric acid. 



2. Nitrate of silver threw down a copious curdy white precipi- 

 tate, which blackened on exposure to the light. Indicating 

 muriatic acid. 



3. Oxalate of ammonia threw down a copious white precipi- 

 tate. Indicating lime. 



4. A portion of the liquid freed from lime by means of oxalate 

 of ammonia was mixed with some carbonate of ammonia, and 

 then a drop of phosphoric acid was added ; but no precipitate 

 nor cloudiness was perceptible. Hence the water contained no 

 magnesia. 



5. A portion of the water concentrated by evaporation was 

 acidulated with tartaric acid, and set aside for 24 hours ; but no 

 crystals of bitartrate of potash made their appearance. Hence 

 the water contained no potash. 



6. Neither pure potash nor quicklime when added to the 

 water occasioned any evolution of ammoniacal fumes. Hence 

 the water contained no ammonia. 



6. Neither prussiate of potash nor sulpho-chyazate of potash 

 occasioned any change of colour. Hence the water contained 

 no iron. 



8. The addition of sulphuric acid occasioned no effervescence. 

 Hence the water contained no carbonic acid and no carbonate. 



9. The water blackened silver, and threw down acetate of lead 

 of a dark brown colour. It contained, therefore, sulphuretted 

 hydrogen. 



From these preliminary trials, I concluded that the saline 

 constituents of the water were the following : 



1. Sulphuric acid. 4. Soda. 



2. Muriatic acid. 5. Lime. 3 



3. Sulphuretted hydrogen. 



