260 QUICKSILVER DEPOSITS OF THE PACIFIC SLOPE. 



early in 1887. The most favorable opportunity for investigating the water 

 at that time was presented at the Fiedler shaft, which communicates below 

 ground with the Hermann shaft. Both had then been abandoned and water 

 escaped from the top of the former into the lake. Its temperature was 

 128° F. (53^° 0.) and it was in a constant state of agitation from tlie es- 

 cape of carbon dioxide and hydrogen sulphide. Large quantities of water 

 were collected in new wooden pails and filtered hot. The filtrate on evap- 

 oration and analysis showed all the substances recorded in the above anal- 

 yses, and, in addition, alumina, manganese, cobalt, phosphoric acid, hypo- 

 sulphurous acid, and some organic matter resembling humic or crenic acid. 

 Repeated experiments showed not a trace of mercury, though the filtered 

 water left small quantities of mercuric sulphide on the filter. 



This water under these physical conditions would thus appear to be 

 incapable of dissolving cinnabar ; for otherwise the suspended sulphide 

 must have been accompanied by the same substance in solution. Tiiis in- 

 solubility is probably ascribable to the ammonia present; for in laboratory 

 experiments we have found that different ammonia compounds precipitate 

 mercuric sulphide from analogous solutions. It is not impossible that at 

 pressures above one atmosphere ammonia compounds lack this precipitating 

 power, and if the waters of Sulphur Bank were always ammoniacal, as they 

 have certainly been for the last twenty years, this hypothesis would account 

 for the fact that no cinnabar whatever appeared at the surface of the Sul- 

 phur Bank, the ore being met with only at a depth of several yards. It 

 would also account for the mercuric sulphide in suspension in the water. 



The ores of the open cuts of the bank were also submitted to a care- 

 ful examination, in order to ascertain the correspondence between their 

 composition and that of the material dissolved in the waters. In inmiediate 

 contact with the cinnabar all of the bases detected in the water were found, 

 but neither chlorine nor boracic acid. A sufficient reason for the absence 

 of these acids appears to be the solubility of the chlorides and the borates, 

 which have never been found in any of the quicksilver mines beneath the 

 surface, though at Knoxville and at Steamboat Springs borax exists in the 

 waters, and it was very probably also present during the time of ore depo- 

 sition at other mercuriferous localities. That the ores of Sulphur Bank 

 have been in contact with solutions of chlorides and borates is very cer- 



