3^2 Aii Analyjis of two Mineral Sprlngi 



with galls. Now, common fulphur is always contaminated 

 with a little fulphuric acid ; and, as neither hepatic gas nor 

 oxygenated fait is here concerned, the effect muft be at- 

 tributed to the acid and the fulphur. If this water be eva- 

 porated, it leaves a matter which does not deliquefce ; but 

 which emits the fame fmell as the refiduum of the hepatifed 

 fblutions. To (hew that the acid is neceflary to the pro- 

 duction of the purple colour, let the fulphur be well wafhed 

 with diftilled water before it is mixed with the iron ; and it 

 will be found that no fuch colour can be now produced. 

 The following fact feems to prove that fulphur may be re- 

 tained in water, in the form neither of fulphur nor of hepatic 

 gas : it is an additional proof how effentially the oxygenated 

 differs from all the common falts of iron. I faturated a di- 

 luted folution of oxygenated muriat of iron, which fcarcely 

 affected nitrat of filver, with hepatic gas. A white preci- 

 pitate fell, but fo minute that it was impoffible to collect it, 

 nor did it deftroy the tranfparency of the water : hence I 

 think it probable that, if the fait were quite perfect, it would 

 not be fenfibly affected by hepatic gas. I now boiled the 

 liquor, to expell the gas, till it wholly loft its hepatic fmell. 

 The liquor was again tried with nitrat of filver ; and there 

 was a copious depofition, but of a dark brownifh colour. 

 It feems certain, then, that fome fulphur is retained by the 

 folution, which cannot be expelled by boiling. 



XIII. THE NEUTRAL SALTS OF THE WATER: MURIAT 

 OF MAGNESIA, MURIAT OF SODA, SULPHAT OF 

 SODA. 



A gallon of the water was evaporated to drynefs ; the de- 

 liqucfcent falts were feparated from the non-defiquefcent; 

 and each of the falts which were thus obtained was care- 

 fully examined. Thus, by procefics which are fufficiently 

 known, it was found that the gallon of water contains of 

 muriat of magnefia 11.5 grains nearly $ muriat of foda 430 



grains; fulphat of foda 152 grains. 



Th« 



