BRIEF OUTLINE OF EESULTS. 



Quicksilver ajipears to be rather more than tliree times as abuudaut iu uature as silver. The 

 quicksilver produced in the -world from 1850 to 1885, Inclusive, weighed 1.74 times as much as the silver 

 produced, but the value of the silver was about 1{).4 times that of the quicksilver. The great quick- 

 silver-producing localities of the world have been Alraaden iu Spain, Idiia in Austria, Huancavelica 

 in Peru, California, and the province of Kwei-Chau in China. No statistics are known to exist of the 

 Chinese product. The total known products of the other regions take rank in the order in which they 

 are named above, but of late jears Peru has produced nothing and from 1850 to 1885 California yielded 

 about half the total product. The production of Italy is more important than it is usually assumed 

 to be. In 1886 the yield was 7,478 flasks. The production of California, which was nearly 80,000 

 flasks in 1S77, was only about 30,000 iu 1880. 



A chain of quicksilver deposits of very greatly varying commercial importance almost girdles the 

 world. Bcgiuuiag in Spain, these depo.sits are distributed along the great chain, including the Alps, 

 Caucasus, and Himalayas to China; thence through Japan along the eastern edge of the Asiatic conti- 

 nent to the Arctic circle. Beginning again iu Alaska, the deposits follow the western Cordilleras down 

 to Chili. Brief descriptions of the more important or more interesting of these deposits are given iu 

 Chapter II and serve as an introduction to the discussions of the deposits of the Pacific slope. 



The sedimentary rocks of the Coast Ranges of California are almost all composed of granitic 

 detritus. A portion of these have been subjected to very intense metamorphism and have been con- 

 verted into thoroughly crystalline rocks, in part schistose. These rocks are of Cretaceous age and are 

 grouped as pseudodiabase, pseudodiorite, glaucophane-schists, iihthanites, and serpentine. Very 

 elaborate field studies, microscopical esaminatious, and chemical analyses of these rocks are given in 

 Chapter III, which is mainly devoted to the investigation of their origin and the processes by which 

 they have become recrystalline. The conclusion reached is that dynamical action, together with 

 warm waters carrying maguesiau salts and silica in solution, cifected the metamorphif n at the epoch 

 of an exceedingly violent upheaval. This chapter also includes an investigation of concretions in 

 sandstone, which are referred to the action of organic matter, and an analysis of the coaditions under 

 which decomposition will produce rounded nodules, like pebbles. 



The massive rocks of the quicksilver areas include granite, ancient porphyries, andesites, rhyolite, 

 and basalt, A new group of andesites is discussed, for which the name asperites is suggested. It is 

 shown that these rocks are of variable mineraloglcal composition, even in the same eruptions, while 

 all of them share a trachytie habitus. The name is simply a latinized equivalent of trachyte. Very 

 remarkable andesit.ic and basaltic gbis-ses occur near Clear Lake in areas of unusual size. These 

 glasses are extremely acid, but contain alsv, a very high percentage of alkalis, and it is because of this 

 peculiar chemical composition that they have failed to crystallize, uot because they have cooled more 

 rapidly or under less pressure than the accompanying cry.stalliuc rocks. An attempt is also made to 

 show that the original crust of the earth was granitic and reasons are given for believing that the 

 MON XIII II XVII 



