Chap. XIX.] 
ORIGIN OF URALIAN GOLD. 
459 
That the gold occurring in quartz-veins in the solid slate-rocks resulted 
from an internal igneous agency may well be suggested, if we judge from the 
appearance which the strings and expansions of the metal indicate as they 
ramify through the chinks of the hard rock, or from the grains diffused in its 
mass. 
In viewing the widely attested fact that the upper portions of the auriferous 
veinstones are infinitely richer than the lower parts of the same, I am naturally 
led to favour the suggestion of Humboldt, that the formation of gold had some 
closer relation to or dependence upon the atmosphere than that of the baser metals 
lead, copper, and iron *. 
What I contend for, however, is, that, if it had been originally so diffused in the 
matrix (which seems to be contradicted by the absence of any grain of gold in 
the original Uralian fragments which compose the Permian conglomerates), still 
the metal must have been formed into veins, geodes, and strings at a compa- 
ratively recent period, and, as I think, by igneous or hydrothermal action from 
beneath. 
Again, the fact is undeniable that, wherever the veinstones in the solid rock 
have not been ground down by denudation, and remain as testimonials of the 
original seat of the gold, the portions which have as yet proved to be the richest 
are those which are at or nearest the surface. Experience too, dearly bought 
in numberless instances, has taught the miner throughout long ages that 
as he follows the veinstones downwards by deep shafts into the body of the 
rock the gold diminishes in volume, so that in many cases the cost of ex- 
traction has been greater than the value of the metal. This simple fact is 
a strong argument against the theory of the formation of gold by a simple 
aqueous solution, and is manifestly in favour of the igneous origin of the metal, 
in which I believe. 
The points which have been alluded to as drawn from personal observation 
in the Ural Mountains, are found to have a world-wide application in every 
tract which has been or is still auriferous. Thus the giant chain of the Andes, 
which has for ages afforded much gold in its range through Chili, Peru, and 
Mexico, is essentially of the same composition, though phenomena discovered in 
South America and in California, since the last edition of this work appeared, 
have, as will hereafter be shown, modified the generalization. The Indians, who 
lived in tracts adjacent to those slaty mountains, followed the simple process of 
picking the shining material from the gravel, sand, and shingle derived from the 
chain ; so that when the Spaniards, the best miners of the sixteenth century, 
first colonized South America, they naturally inferred that, if ignorant natives 
could thus gather sufficient quantities of gold to roof the palaces of their sove- 
reigns, they, as skilful Europeans, might extract incredible quantities from the 
bowels of mountains the mere detritus of surfaces of which had contributed such 
a vast amount of gold. But, as surely as deep mines frequently enriched the 
Spanish speculators who sought for copper and silver, so surely gold-mining in 
the solid rock proved abortive t, owing to the slender downward dissemination 
of gold in a hard and intractable matrix. 
Helmersen and Hoffmann in the ' Annuaire des 
Mines de Kussie,' and Adolf Erman's ' Keiae urn 
die Erde,' as well as an account of the general 
diffusion of gold and a valuable gold-map of the 
world by that author. 
* The eminent metallurgist, Dr. Percy, however, 
who has detected minute quantities of gold in 
many lead-ores, has told me that he is disposed to 
believe that the precious metal may also have been 
thrown down by deposition from an aqueous me- 
dium. 
f It has been too much the habit to underrate 
the capacity and skill of the old Spanish miners, 
though it is known from Humboldt that during 
the government of the monarchy in South Ame- 
rica many of their works were well conducted ; 
