$2 ALUMINOUS CHALYBEATE SPRING IN I. OF WIGHT. 



Sulphuric acid. 1. Tofour ounces of the water was added nitrate of barytes 

 till the whole of the sulphuric acid was precipitated; the 

 sulphate of barytes thusobtained being carefully edulcorated, 

 and heated to redness in a platina crucible, weighed 1 8-5 

 grains, which correspond to 74 grains of sulphate of barytes 

 from a pint of the water. 



Muriatic acid. &. Four ounces of the water were treated with nitrate of 

 silver as long as any precipitate appeared, and the muriate 

 of silver thus obtained, being well edulcorated, and after- 

 wards b ought to a state of incipient fusion by the heat of 

 an Argand lamp, weighed 2*05, which is equivalent to 8*2 

 grains of luna cornea, or four grains of muriate of soda*> in 

 eaek pint of the waterf. 



Sect. XIV. Sulphate and Muriate of Soda, 



IxawfMKitioa J. The mode in which I first attempted to ascertain the 

 Cm alkaline presence of alkaline salts in the water was that alluded to 

 in a former part of this paper, which consisted in precipi- 

 tating the iron and the earths by subcarbonate of ammonia, 

 evaporating the clear solution to dryness, heating the dry 

 mass to redness, with a view to drive ofiTthe sulphates and 

 snaviates of ammonia, redissolving the residue in water, and 

 evaporating again very slowly in order to obtain crystals. 

 But the saline mass yielded by this process did not crystallize 

 regularly, and, on being examined by reagents, was found 

 to contain only sulphate of soda, with minute quantities of 

 sulphates of alumine and magnesia, which had escaped the 

 action of the carbonate of ammonia. 



jkrtrtion, obtained by Dr. Henry, of one hundred grains of ammoniaeo- 

 .snagne^ian phosphate dried at Q0°, for one hundred and eleven grains 

 ©f crystallised sulphate of magnesia, would have led to a very similar 

 jpsult. (Se* Dr. Henry's 'Analysis of several varieties of ~alt,' in 

 fMiitos Trans, for iSiO, page 113.) [Journ. vol. xxvi, p. 277.] 



* ] have fouiid by direct experiments, that one hundred grains of pure 

 m iriateof soda heated to redness, and decomposed by nitrate of silver, 

 yield 241 '6 grains of luna Cornea heated to fusion. 



j The same experiment was tried three times upon different speci- 

 mens of the water, and I here g'r, e the average The smallest quantity 

 «df lana cornea obtained was two grains, and ihe largest 2*5, grains, a 

 {liiTcrence too great to srise from mere inaccuracy. From this and 

 jevfral other circumstances 1 have reason to suspect, that the water is 

 iuMcet to occasional variations in the proportions, ac well as in the 

 *JP e S ale ^antity of, its solid, convents. 



