3.60 An Analyfis of tivo Mineral Springs 



tin&ure of galls (iv. 5.), yields the fame refult. By ufing' 

 a large quantity of the water, I collected fufficient for exa- 

 mination. This I put over a fire ori an iron plate : the ve- 

 getable part took fire and burnt away : the powder became 

 of an ochry yellow, and was magnetic :— fufed with borax 

 by the blow-pipe, it acquired the rednefs which manganefe 

 imparts. 



3. The fame fact may be proved by a (ingle experiment. 

 It is known that tartrite of pot alii decompofes falts of man- 

 ganefe by a double affinity ; in confequence of which; tar- 

 trite of manganefe, which is a fubftance infoluble in wa- 

 ter, precipitates *. I poured, therefore, a folution of tar- 

 trite of pot-afh into water, and there fell a copious crystalline 

 precipitate. Much iron fell down with the manganefe, as 

 might be expected from the affinity between the oxydes of 

 thefe metals : fcr, by fufmg the precipitate with nitre, greet* 

 fpots were formed on the fides of the crucible. 



Tartrite of pot-afh decompofes likewife falts of lime, at 

 is well known •, but the tartrite of lime is precipitated in" 

 the form of a white powder, which is not fenfibly cryftalline. 

 But as there is a great abundance of lime in this water 

 (xiv.), it feems probable that it had entered into the com- 

 pofition of thefc cryftals. 



Manganefe has been but rarely noticed as entering into 

 the compofiticn of mineral waters. The reafon, perhaps, is, 

 that it has been feldom looked for, rather than that it feldom 

 exifts •, fince it is now known to be a fubftance abundantly 

 diffufed through the earth. The waters of Aftrop, which 1 

 have mentioned above (m. 2.), decompofe tartrite of pot- 

 afh, and form a cryftalline precipitate when its carbonate of 

 lime has been thrown down by boiling. This water, iir 

 thefe circumftances, hardly affects either tincture of galls or 



fides that I defcribe only what I have fcen, it will appear that the fait in 

 queftion is of fo peculiar a nature, that it cannot be expected to obey the 

 ufual analogies of the other folutions. 

 * See Sch'etle as above. 



pruf&at 



