California Gold Region. 153 
strata forming innumerable receptacles or “ pockets,” as they 
are called, into which the metal has originally found its way 
from its own gravity assisted by aqueous agency. It is this 
accidental association of the gold with the slate-rocks which 
has caused the statement to be frequently made, even by per- 
sons of much general intelligence, that the gold exists in the 
body of the rock itself, and forms a component part of it, in 
the same sense that iron pyrites forms a part of the rocks in 
which it occurs. But I have no where seen gold ameng the 
slate, except in circumstances where its presence could be 
accounted for by its introduction from without, a close scrutiny 
readily discovering some cleft or opening through which it 
might have entered. The richest of these “ pockets” are in the 
bottoms of sharp ravines, which seem to have been notched into 
the body of the slate, and generally in situations where the bot- 
tom of the ravine, after descending at a considerable inclina- 
tion for some distance, becomes more nearly horizontal. Just 
below a sudden descent or precipice, in the bottom of a dry 
ravine, gold is often found in the cavities in great abundance. 
From such a spot Mr Douglas extracted a pound of gold in 
a few hours, even after the place had been previously “ dug 
out,”’ as was supposed, and abandoned. 
I have noticed, in published accounts, many erroneous state- 
ments respecting the geological position of the gold. Some 
have said there is no porticular formation in which the gold 
occurs, but that, in different places, it is found in different 
kinds of earth or rock. You will not need to be informed 
that this is without foundation. So far as I have been able 
to examine, or can learn from competent witnesses, there is 
but one geological formation with which the gold of the 
Sierra Novada is associated, and in which it uniformly oc- 
curs. This is the stratum of drift or diluvium, composed of 
a heterogeneous mixture of clay, sand, gravel, and pebbles, 
and varying in thickness from a few inches to several feet. 
Here, as elsewhere, this stratum is neither horizontal nor of 
uniform slope, but conformed to the varying inclination of 
the earth’s surface, covering the declivities, and even the 
summits of the hills, as well as the bottoms of the ravines 
and valleys. Out of this stratum I have nowhere found 
