26 QUICKSILVER DEPOSITS OF THE PACIFIC SLOPE. 



Judging from the specimens, it would appear, as already mentioned, that 

 nearly or quite all of the quicksilver was originally deposited in the metallic 

 state and that the sulphide accompanying it is of secondary origin. Now, 

 though more or less native quicksilver often accompanies deposits of cinna- 

 bar, the metallic mercury usually forms but a small proportion of the entire 

 ore. To this rule there are some exceptions. At the Rattlesnake mine, in 

 California, for example, a large part of the quicksilver was native, but here, 

 and at other points in the same State at which native quicksilver was abun- 

 dant, it was also accompanied by unusual quantities of bituminous oils, which 

 were probably not without effect upon the form in wliich the metal was 

 deposited. Near Montpellier, France, also, quicksilver has been found in 

 some quantity, so far as I know unaccompanied by cinnabar. But the depo- 

 sition of quicksilver, almost exclusively in the metallic state, from waters such 

 as that of the Great Geyser, containing soluble sulphides and little or no or- 

 ganic matter, is very liard to understand. It is also very difficult to account 

 for the distribution of the metal on the supposition that it was brought to the 

 surface in solution by the heated waters. The basin of the Great Geyser 

 is extremely symmetrical; in other words, the deposition of mineral matter 

 takes place with great uniformity on all sides of the vent. Now, although 

 the quantity of quicksilver found was by no means inconsiderable at a 

 single spot, it was detected nowhere else in the basin. It seems highly 

 improbable that the metal should have been deposited from the water 

 without any approach to symmetr}- of distribution. In the opinion of Mr. 

 Des Cloizeaux, it is not difficult to imagine circumstances under which a 

 barometer might have been broken at the point where the mercury was 

 found. The water sinks periodically into the vent, leaving the point in 

 question bare, and returns again with a rush. An observer, taking the op- 

 portunity to advance as close to the vent as possible, would have to fly for 

 his life as the water returned, and might well drop his instruments. 



Professor Bunsen, who, as is well known, was engaged in investigating 

 the geysers at the same time with Mr. Des Cloizeaux, also examined this 

 occuiTence of quicksilver, and has informed me that in his opinion it was 

 certainly the result of an accident and was not a natural deposit. 



