Mr. Brande on the Mineral Waters of Windsor. 265 



salt and slightly bitter, without the smallest admixture of any 

 chalybeate flavour. 



The specific gravity of the stronger water is 1010.4; that of the 

 weaker, 1007.7. Of the former, one pint measure (holding one 

 pound avoirdupois of distilled water at 00°) afforded, on evapora- 

 tion, 88 grains of dry saline residue ; of the latter, a pint measure 

 yielded 65 grains of residue. As the contents of these waters 

 almost exactly resemble each other in quality, it will only be 

 necessary particularly to describe the nature of the stronger 

 spring. 



On applying heat to the water, a small portion of carbonic 

 acid escaped, it gradually became opalescent ; and when it boiled, 

 was turbid, and let fall a white powder, which was presumed to 

 be carbonate of lime, deposited, as is usually the case, in conse* 

 quence of the loss of the excess of carbonic acid previously hold- 

 ing it in solution. But on examining the precipitate, it was 

 found to be carbonate of magnesia, the source of which was not 

 at first very obvious, more especially as the water was slightly al- 

 kaline after having been somewhat reduced by evaporation. 



A pint of the water mixed with excess of carbonate of ammonia, 

 and boiled down so as to precipitate the earths of the earthy salts, 

 afforded a mixture of carbonate of lime and of carbonate of mag- 

 nesia, which being dissolved in excess of muriatic acid, neu- 

 tralized by ammonia, and decomposed by oxalate of ammonia, 

 yielded a precipitate, from which 1.25 grains of lime were ob- 

 tained. The remaining solution, evaporated to dryness and' 

 exposed to a red heat, afforded a residue of 21.25 grains of mag- 

 nesia. 



The only alkali present in the water was soda, which, esti- 

 mated in the state of sulphate, amounted to 10.52 grains of dry 

 soda. 



The quantity of sulphuric and muriatic acids present was deter- 

 mined by precipitation with muriate of baryta and nitrate of silver 

 —the former furnished a precipitate equivalent to 33 grains of dry 

 sulphuric acid — and the latter to 21 grains of muriatic acid. The 

 combined carbonic acid in the water was estimated at 0.98 grains. 



