The surface gold in California will in a few years be measurably exhausted; the occasional discovery of new deposits cannot long postpone such a result; nor will it be delayed for any great number of years, by any more scientific and thorough method of securing the treasure. California will prove no exception in these respects to other sections of the globe where surface gold has been found. The great question is, will her mountains be exhausted with her streams and valleys? Will her rock gold give out with her alluvial deposits? The gold-bearing quartz is the sheet-anchor at which the whole argosy rides; if this parts, your golden craft goes to fragments. When an old Sonoranian told me in the mines that the quartz _sweated_ out the gold, all the young savans around laughed at the old man’s stupidity; and I must say the _perspiration_ part of the business rather staggered my credulity, which has some compass, where there are no laws to guide one. But the old digger was nearer the truth than many who have more felicitous terms in which to express their theories. Though the gold may not ooze from the quartz as water drips from a rock, yet it is _there_, and often beads from the surface like a tear that has lost its way among the dimples of a lady’s cheek. In other instances it shows itself only in fine veins; and in others still, is wholly concealed from the naked eye, and even eludes the optical instrument; but when reduced to powder with the quartz, flies to the embrace of quicksilver, and takes a virgin shape, massive and rich. The specimens of quartz which have been subjected to experiment, have yielded from one to three dollars the pound. These specimens were gathered at different points, in the foot range of the Sierra Nevada, and are deemed only a fair average of the yield that may be derived from the quartz.