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the mortars have “ in almost every instance been found by 
miners in their search for gold.-” 
Another point to be remarked is that they seem always to 
be found in the auriferous gravels. 
We know very well that Cortez found the temples and 
palaces of ancient Mexico resplendent with gold, and Dr. 
Daniel Wilson, in his charming but incautious work on 
Prehistoric Man, tells us that “ the metallurgic arts were 
carried in some respects further by the Mexicans than the 
Peruvians. Silver, lead, and tin were obtained from the 
mines of Tasco, and copper was wrought in the mountains of 
Zacotollan by means of galleries and shafts opened with per- 
severing toil where the metallic veins were imbedded in the 
solid rock.” 
A thousand years, perhaps, before Cortez landed in Mexico 
the Toltec civilisation flourished in Central America, in Ana- 
huac, and on the Pacific coast, and centuries before the palaces 
of Montezuma glittered with the precious metals the precur- 
sors of the Aztecs had mined into the auriferous gravels of 
the Sierra Nevada and the Sacramento Valley. The relics 
which I have described were evidently left where they have 
been found by gold-hunters, and it is hardly credible that gold 
excited the cupidity of man in the Pliocene epoch. 
If it were impossible to suggest an explanation of how 
these granite mortars and dishes got into the heart of Table 
Mountain, could persons having no theory to maintain accept 
the conclusion of Professor Marsh and Professor Whitney that 
the human bones and stone mortars and the geological stratum 
in which they are found are of the same age ? If we should 
find a vase of gold coins in the same position, would it be 
reasonable to draw the conclusion that there were human 
beings in the Tertiary age who had some idea of finance and 
made use of coined money ? W ould it not be more sensible 
to seek some other explanation, and, if none were found, still 
to refuse to believe that gold was coined into money before 
the Glacial Epoch ? 
It 'seems to me that we already have the clue to the presence 
of these mortars and pestles in the auriferous gravels in the 
fact I have cited, that they seem always to be found in these 
gold-bearing gravels and nowhere else. 
I have quoted also from Dr. Wilson to show that the 
primitive inhabitants were capable of boring into the bowels 
of the mountains to obtain gold and silver. 
Mr. Bancroft, in his great work to which I have referred, 
testifies to the same fact. Both gold and copper, he says, 
were mined in Mexico from veins in the solid rock, extensive 
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