Page:Mexico, Aztec, Spanish and Republican, Vol 2.djvu/469

Rh troy. It appears from his calculations that seven-eighths of all the deposits made at his mint from the commencement of the business until April 1850, exhibit a variation in quality of only fifty-cents per ounce troy, the fineness averaging between 873½ thousandths and 898½ thousandths. The general fineness of nearly all the gold brought to the mint is 886 thousandths; the flat spangles of the rivers, which bear a small proportion to the mass, averaging 895 thousandths. The alloy detected in this gold is wholly silver tinged with a small quantity of iron, and the removal of the iron, dirt or sand in melting occasions usually a loss in weight of about 3½ per cent. If the grains have been cleansed by the magnet the loss is reduced to about 2½ per cent., but if they are wet or dampened the loss may raise to even higher than 4 per cent. California gold is regarded as consisting of 995 parts gold and silver in every 1000 parts by weight, which renders it necessary to separate these metals before converting them into coin, for, according to law, the standard national gold is so constituted, that, in 1000 parts by weight, 900 shall be pure gold, and 100 an alloy, compounded of copper and silver.

If the confident representations of travellers, miners, laborers and scientific men are to be heeded, the California placeres and mines will continue to yield an increasing ratio of precious metal; but time alone can disclose the degree in which their products will be multiplied. Should they reach $100,000,000 annually—and they may surpass that amount—the yearly addition to the gold of Europe and America, will be 6½ per cent, on $1,800,000,000, which is the estimated amount of that metal in those two quarters of the globe. This vast sum more than doubles the past contributions of American mines during the period of their greatest productiveness.

Gold, however, is not the only important mineral element of California's wealth. Her quicksilver mines are believed to be numerous, extensive and valuable. The cinnabar ore which produces the quicksilver, lies near the surface, is easily procured and is represented to be remarkably productive. The mine of New Almaden is a few miles from the coast, midway between San Francisco and Monterey, and in one of the ridges of the Sierra Azul. The mouth of this mine is a few yards from the summit of the highest hill that has been found to contain quicksilver, and is about 1,200 feet above the neighboring plain and not much more above the ocean. Its ore-bed seems to be embraced in a greenish talcose rock. By a very rude