Bromine in the natural brine of Salina. 143 



By evaporation, minute, but distinct crystals of a rhombic, or cubical 

 form separated, and a crust of indistinct forms was left. A solution 

 of this salt in water, did not occasion any precipitate when added in 

 successive portions, to a drop of a solution of bi-chloride of mercury ; 

 with pro-nitrate of mercury, there was an abundant white precipitate ; 

 also with nitrate of lead, a white precipitate. 



IV. Another part of solution I. was evaporated, and the dry salt 

 digested in pure alcohol ; by evaporating the solution, a salt, in milk 

 white cubes separated, and a crust of apparently prismatic crystals re- 

 mained. Alcohol dissolved them without leaving any residue, and the 

 solution being mixed with a drop of chloride of platina, potassa chloride 

 of platina, in the form of fine yellow powder, was precipitated. The 

 proportion of hydro-bromic acid in these waters, seems by the action 

 of reagents, to be much less than that of hydriodic acid ; the quan- 

 tity of potash is also inconsiderable. As it is probable that bromine 

 in combination, exists in many of our waters, a convenient method for 

 ascertaining its presence is desirable, particularly, as a minute scale of 

 experimenting is unavoidable. The characters observed in I. led 

 me to adopt the following. A few drops of pure water are mixed 

 in a conical glass, with a drop of sulphuric acid, and half a volume of 

 a cold solution of starch ; a few bubbles of chlorine are passed through 

 the mixture, which is then left at rest, that the diffused starch may 

 unite at the bottom. A glass rod dipped in the fluid supposed to con- 

 tain bromine, is then applied to the surface of the fluid in the glass ', 

 orange colored, dense striae descend from the rod, and rest for some 

 time on the starch, if bromine alone is present. If the solution con- 

 tains iodine also, the appearance is the same, but the striae are deep 

 blue ; in a few seconds the blue disappears, and the characteristic 

 orange yellow of the solution of bromine remains ; extremely minute 

 quantities of these substances may be thus distinguished. 



Bromine in the natural brine of Salina. 



Having enjoyed, during the late winter, some opportunities of ob- 

 serving the remarkable properties of bromine ; and having learned 

 also that it has been discovered in various saline waters in England,* 

 and other countries, I was desirous of ascertaining whether it exists 

 in any of the saline waters of this country, to which I have access. 



By Dr. Daubeny and Mr. Murray. 



