150 ECONOMICAL MINERALOGY. 



It is a spring which issues from the earth in sufficient volume to turn a light grist mill. Such 

 an immense laboratory of sulphuric acid is here conducted by nature, that all the water which 

 supphes this perennial stream possesses acidity enough to give the common test with violets, 

 and to coagulate milk. Besides the above, there are said to be several other sour springs in 

 this vicinity.* 



I have particularly examined both the liquid acid, and the brownish vegetable matter sub- 

 jected to its action. 



The liquid is transparent and colourless ; and in the specimen upon which I operated, had 

 a specific gravity of 1 .11304 at 60° F. It reddens litmus powerfiilly, has an intensely sour 

 taste, causes a dense precipitate when added to muriate of barytes, but is not affected by 

 nitrate of silver. When ammonia is added to the liquid to saturation, a slight precipitate of a 

 reddish colour is the result, and the clear solution is afterwards also slightly affected by oxa- 

 late of ammonia. The oxide of iron and lime indicated by the two latter tests are, however, 

 in very small proportion ; as is evident from the fact, that when the liquid is evaporated, it 

 leaves only a trifling residuum. It is a nearly pure, though dilute, sulphuric acid, and not a 

 solution of acid salts, as has been supposed ; for the bases are in too minute proportions to 

 warrant the latter opinion. 



The brownish matter, or acid earth, is principally vegetable matter, charred by the action 

 of the acid ; but it also contains some silica and alumina, with a minute quantity of lime and 

 oxide of iron. When this matter is boiled in water, a solution is obtained which possesses 

 all the properties of the liquid just described. When heated for some time in a crucible to 

 redness, the acid and vegetable matter disappear, and there remain a little sulphuret of cal- 

 cium formed by the decomposition of the acid and the lime, a trace of iron, together with the 

 earthy matters above mentioned, I could not detect, either in the hquid or in the solution of 

 the earth, any other salt than those which I have already enumerated ; unless, indeed, there 

 should be some sulphate of alumina present. 



The occurrence of sulphuric acid in nature, in any thing like the pure form which it here 

 possesses, is of great interest ; only a few localities, and these rather doubtful, being hitherto 

 known. In most of these, too, the acid is quite dilute ; and the occurrence is, moreover, 

 principally confined to volcanic districts.! An earth, somewhat similar to that found in Byron, 

 is said to exist in great quantities at a village called Daulakie, in the south of Persia, between 

 three and four days journey from Bushire on the Persian Gulf. The natives employ it as a 

 substitute for lemons and limes, in making their sherbets, of which considerable quantities 

 are drank, they being prohibited the use of wine. On analysis, the acid was found to be the 

 sulphuric, and this was united to iron ; the solution in boiling water, when evaporated, yielding 

 crystals which seemed to be the acid sulphate of that metal.:]: 



Acid springs or wells are also found in the town of Bergen, in this county. 



* Eaton. American Journal of Science, XV. 239. f See Gairdner on Mineral and Thermal Springs, 



i Philoiophical Magazine for 1824. 



