ALUMINOUS CHALYBEATE SPRING IN I. OF WIGHT. £J 



paler when the water had not previously been exposed to 

 the atmosphere. . 



I. Alkaline solutions produced copious greenish floccu* 

 lent precipitates, which became darker on standing in the 

 air. 



K. Nitrate of silver occasioned a dense, white, but not 

 considerable precipitate. 



L. Both muriate and nitrate of barytes occasioned co s * 

 pious white precipitates. 



M. A piece of marble being boiled for some time in a 

 few ounces of the water, the marble was found to have un- 

 dergone no sensible loss of weight by this operation ; but it; 

 surface had acquired a faint yellowish tinge. 



N. A quantity of the water beiug evaporated to dryness, 

 and a considerable degree of heat applied to the dry residue, 

 a solution of this in water hadthe same effect of reddening- 

 litmus as before. 



Sect. IV. Inferences arising from these Effects. 



1. From experiment A, connected with experiments C, Inferences 

 H, I, M and N, and from the circumstance of taste, and 



other general properties, it appeared highly probable, that 

 the water contained sulphate of iron, and perhaps also sul- 

 phate of alumine, without any uncombined acid*. 



2. From experiments C and D, it appeared evident that 

 iron and lime were contained in the water, and that their 

 solvent was not carbonic acidf. 



3. The experiments D and E concurred to show, that 

 the water did not contain any sensible quantity of car* 

 bonates. 



4. The experiments F and G afforded additional evi- 

 dence of the presence of iron, and, while they showed the 

 existence of lime in the water, seemed to indicate, that the 

 quantity of this earth was not considerable. 



* Solutions of sulphate of iron, and sulphate of alumine, though 

 made from these salts in their crystallized state, have, like acids, the 

 power of imparting a red colour to litmus. 



f The reddish flakes mentioned in C and D, and in Sect. II, q, are 

 uniformly found to be sab -sulphate of iron. 



5. It 



