CHAPTEE XV. 



ON THE SOLUTION AND PRECIPITATION OF CINNABAR 

 AND OTHER ORES.^ 



The Avaters of Steamboat Springs are now depositing gold, probably 

 in the metallic state; sulphides of arsenic, antimony, and mercury; sul- 

 phides or sulphosalts of silver, lead, copper, and zinc; iron oxide and pos- 

 sibly also iron sulphides; and manganese, nickel, and cobalt compounds, 

 with a variety of earthy minerals. The sulphides which are most abun 

 dant in the deposits are found in solution in the water itself, while the re- 

 maining metallic compounds occur in deposits from springs now active or 

 which have been active within a few years. These springs are thus actu- 

 ally adding to the ore deposit of'the locality, which has been worked for 

 quicksilver in former years and would again be exploited were the price 

 of this metal to return to the figure at which it stood a few years since. 

 At Sulphur Bank also ore deposition is still in progress, but under condi- 

 tions which differ somewhat from those presented at Steamboat Springs. 

 The waters of the two localities are closely analogous. Both contain so- 

 dium carbonate, sodium chloride, sulphur in one or more forms, and borax 

 as princi[)al constituents, and both are extremely hot, those at Steamboat 

 Springs in some cases reaching the boiling-point. The water of Sulphur 

 Bank is ammoniacal. In attempting to determine in what forms the ores 

 enumerated can be held in solution in such waters, it is manifestly expe- 

 dient to begin by studying the simplest possible solutions of the sulphides, 

 and particularly of cinnabar. 



Previous investigations. — Thc solubility of mcrcuric sulphide in alkaline com- 

 pounds containing sulphur has long been recognized by experimental and 



' A digest of this chapter appeared in the Am. Jour. Sci., 3d series, vol. 33, 1S87, p. I",»;). 



419 



