DEEIVATION OF CINNABAR FROM GRANITE. 447 



with volcanic eruptions, are known in many cases to reach the surface at 

 distances as great as tliis tVoui hiva vents. Tliougli tlie cases in which cin- 

 nabar in greater or smaller quantities occurs close to hot springs in the 

 Coast Ranges are numerous, not .all such springs are known to be accom- 

 panied by quicksilver. If the granite be supposed to be the source of the 

 metal, this may at first sight seem strange. But granite is by no means a 

 homogeneous substance, and, as I have pointed out in Cha])ter IV and else- 

 where, was probably never thoroughly fluid. With reference to the small 

 quantities of heavy metals which this rock is known to contain in various 

 European localities, the composition is known to be capricious. It is alto- 

 gether probable, therefore, that some parts of the granite underlying the 

 Coast Ranges may contain much more ipiicksilver than others, and this 

 irregularitv of diffusion, in combination with the want of uniforniit\' in the 

 amount of granite leached by diflierent hot springs, would be sutficient to 

 explain all the observed diversities in the deposits of cinnabar. 



Evidence at Steamboat Springs, — At Stcamboat Sprlugs a vaHety of mclals oc- 

 cur ill the deposits from the active springs, and two concurrent quantitative 

 analyses, together with many partial analyses, show that the relative quan- 

 tities of the metals are as follows, begimiing with the largest: antimony, 

 arsenic, lead, copper, quicksilver, gold, and silver. The quantity of Clipper 

 found was five times as great as that of quicksilver. If these same metals 

 could be found in the granite it would establish the highest probabilit\- that 

 the metals of the deposits were derived from the granite. Anah'ses of large 

 quantities of very fresh granite, showing no effects of solfataric action and 

 collected half a mile from any solfatarically decomposed material, failed to 

 show all of the.se metals, but succeeded in revealing the presence of those 

 most abundant in the deposits, viz : antimony, arsenic, lead, and copper. 

 No mercury could be detected; yet the fact that four metals are conunon to 

 the deposits and the granite and the coincidence that the.se metals are the 

 most abundant in the spring deposits are highly suggestive of derivntion 

 from the granite. There is some evidence that the failure to find ([uicksil- 

 ver in this granite was due to irregularity in the composition of the massive 

 rock. The only portion of the solfatarically decomposed area of Steambont 

 in which cinnaljar is abundant enougrh to be visible is at the extreme west 



