Gray Sulphur Springs of Virginia. . 105 



H. For Crenic Acid. — 'To the liquid thus treated in G, was added, 

 in excess, the bi-carbonate of ammonia, and afterwards acetate of 

 copper : a green precipitate was thrown down, proving the presence 

 of crenic acid. 



I. For Combined Hydro- Sulphuric Acid. — The freshly opened 

 water was added to a solution of sulphate of zinc, without occasion- 

 ing any precipitate ; from whence it was inferred that the hydro-sul- 

 phuric acid present, exists in a pure state. 



J. For Fluorine. — To half a pint of the water, was added acetate 

 of lead, in order to convert its carbonates into acetates, so that the 

 fluo-silicic acid, if present, might not be carried off too rapidly along 

 with the carbonic acid gas ; the solution was evaporated to dryness 

 and treated in a platina crucible with sulphuric acid, — a moistened 

 evaporating glass being held over it ; no indication of hydro-fluoric, 

 or fluo-silicic acid gas was afforded. 



K. For Chlorine.— To the water was added a solution of nitrate 

 of silver ; it instantly produced a brownish precipitate, which was 

 insoluble in nitric acid. Hence chlorine is an ingredient in this water. 



L. For Iodine. — The residuum from half a pint of the water was 

 transferred to a test tube, and upon It was poured two inches of ge- 

 latinous starch : sulphuric acid was carefully suffered to trickle down 

 the side of the tube, so long as any action was observable on the 

 residuum : no change of color was noticed In the starch, and hence 

 iodine Is not present. 



M. For bromine.— Half a pint of the water was evaporated to one 

 twentieth its bulk, Introduced Into a vial one Inch and three quarters 

 wide, and rendered yellow by passing through it a stream of chlo- 

 rine. Sulphuric ether was added ; the mixture well shaken and 

 suffered to rest. The ether mounted to the top of the fluid, but 

 without exhibiting the characteristic color of bromine. 



N. For Alkaline bases. — Infusion of purple cabbage was added 

 to the water. In one hour It had changed to green near the surface ; 

 and after the expiration of twelve hours, the alkaline reaction was 

 obvious throughout the fluid. Tincture of alkanet was instantly 

 changed to blue. 



O. For Potassa. — The residuum of the water previously cleared 

 of lime was dissolved In nitric acid, and to the solution, tartaric acid 

 was added : no crystals of the bi-tartrate of potassa made their ap- 

 pearance, hence no potassa Is contained In this water. 



Vol. XXX.— No. 1. 14 



