REVIEWS 857 
the ascending waters came charged with metallic minerals from the 
bathysphere, meaning thereby a region in the interior of the earth 
which is richer in heavy metals than any part of the earth’s crust 
that comes under our observation ; for this simple assumption affords 
no explanation why metallic minerals are concentrated in one part 
of the earth’s crust and not in another, and it supposes a free flow 
of waters at greater depths than in our present state of knowledge 
of terrestrial physics it is considered possible that channels which 
would admit ofa flow of water through them would remain open. 
“Furthermore, if the vein-materials are found to form a constituent 
part, even in minute traces, of comparatively fresh and unaltered 
country-rocks in a given ore-bearing region, and at such distances 
from any water-channels as to render it improbable that these mate- 
rials could have been brought in through these channels, it is reason- 
able to assume that these or similar rocks have been permeated by the 
waters from which the known ore deposits were precipitated, and that 
from them they derived their contained vein-materials. .... It 
seems probable that not only the recent eruptives, but the older 
granites through which the ascending solutions must have passed, con- 
tain enough of the precious metals, and, it may be assumed also, of 
the other vein-materials to furnish, in the long time that is accorded 
to the accomplishment of most geological phenomena, sufficient mate- 
rial of the formation of existing ore-bodies. The analysis of the 
vadose waters in the Geyser mine has demonstrated the capability 
possessed by even cold surface waters of taking up such materials in 
their passage through the rocks. The subterranean waters that were 
circulating here at the time of the formation of the ore-deposits must 
have been much more energetic solvents, being heated by contact 
with the cooling masses of igneous rock, and probably deriving a cer- 
tain amount of active and energetic mineralizing agents, such as 
fluorine, chlorine, etc., from these igneous masses at the time of con- 
tact. Hence it is fair to assume that the vein-materials in this region 
were originally derived from both recent and ancient eruptive rocks 
—a conclusion similar to that arrived at by Mr. Penrose, from his 
more exhaustive study of the ore-deposits of Cripple Creek.” 
The Occurrence and Treatment of Certain Gold Ores of Park County, 
Colorado. By B. SADTLER, pp. 848-853. 
The Occurrence of Gold Ores in the Rainy River District, Ontario, 
Canada. By Wn. H. MERRITT, pp. 853-863. 
