[12]. It is not long, since a list of the peons who had escaped from the other side of the Rio Grande was published, and bitter complaints made by their masters to the Mexican Government, which was petitioned for redress! It is said that some proprietors own thousands, and they are a part of their estates. It is probable that neither slavery nor peonage can continue on the borders of the Rio Grande. During our military operations a large number of persons were freed by earning the means of paying the debts for which they were bound.
APPENDIX.
[From the Republic.]
Messrs. Editors: Some time last Spring, I published in the “Commercial Journal,” of Pittsburgh, some views on the subject of the California gold region, which have been confirmed by observations on the spot, published in the “Alta California,” and by accounts still more recent from that country.
In order to understand the views referred to, it is necessary, in the first place, to give a sketch of the geological features of the country. A valley of six hundred miles in length, and from fifty to a hundred in width, is formed by the Sierra Nevada, or Snowy range on the east, and by the coast range on the west. This valley is watered by two rivers, the Sacramento and the San Joachim; one rising due north, the other due south, and running towards each other; after uniting their waters they enter the bay of San Francisco, which partly bounds the western side of the valley. These rivers may be said to wash the base of the Sierra Nevada, their waters being supplied, almost exclusively, by streams which take their rise in that range of mountains. In this manner they form a continued line although coming from opposite directions, receiving the drainings and detritus brought down by the innumerable torrents which cut the sides of the Sierra. The alluvial and diluvial deposites are, therefore, almost exclusively on the eastern side; and this accounts, also, for the overflow of the river on that side. On looking at the map of Colonel Fremont, I was struck with the extraordinary number of these ravines. They look like so many streaks on the map, or, rather, lines drawn by artificial agency; but that agency is the sudden melting of the snows, and heavy rains of that climate. One cause of this great quantity of water discharged by the short mountain torrents, is the want of sufficient elevation of the mountain, in that latitude, to retain the snows until they can melt gradually, as is the case of the Andes of Peru and Chili; and yet sufficiently elevated to receive a great depth of snow. This, when melted by the rains, rushes down with great force, carrying detritus along with it, and cutting through all the incumbent strata, until it reaches the level of the rivers, although still above the trap, or granite, which forms the nucleus of the mountain.
As this detritus is carried down, it becomes more and more disintegrated, until its further progress is arrested by the course of the rivers before mentioned, and is at last deposited in fine sand and gravel. The metallic threads are found, probably, not less than one-third of the way up the mountain; and if a shaft were sunk at the base of the mountain, it would have to go a depth before reaching the vein, corresponding with its present elevation above the original level. The metal, therefore, will only be found in these alluvial deposites, not beyond twenty or thirty feet in depth, formed in the course of time by the descending torrents. The nearer the river, and the farther from the seam, the finer will be the particles of gold; and the higher up the coarser, and less separated from the quartz in which it is detained. The most expensive part of mining, reducing the quartz to sand by stamping, the amalgation with quicksilver, and the separation of these by distillation, is thus saved, and the gold obtained with comparatively little expense. The stamping, or breaking up of the quartz, is performed by the natural agency of the water, and by the rocks falling upon each other in the course of their descent. Until these deposites shall be partially exhausted, although a much more precarious pursuit than regular mining, the latter will not be generally resorted to. There is no doubt, also, that others, with more perfect machines for washing and amalgamation, will follow those pioneers, and wash the same earth and sand over again, to as great profit as at the first operation. When I examined the lead mines of Missouri, I found that those who came after the regular smelters, took their scoria and leavings, and extracted, by means of the ash furnace, about twenty-five per cent., in addition to the fifty already obtained, but without the expense and uncertainty of mining, which rendered it a sort of gambling pursuit.
Having giving this brief description, I will now proceed to what may be called theory—that is, facts derived from induction. Let us suppose a series of horizontal strata, one above another, but of unequal depth, incumbent on the original unstratified mass, which forms the nucleus of the globe. According to geologists, this was the natural position. Now, in consequence of some powerful volcanic agency, the lower mass is thrown up from below, and becomes the nucleus of a mountain, and that which was before the lowest, now appears at the top, while the various strata which lay flat upon it are tilted up on its sides. These being cut through, in the manner described, there is exposed to view in these cuts, the various strata and their contents, in the same manner as if a shaft had been sunk through them in their horizontal position. If there be any metallic seams to the right or left of these cuts, they will be seen like threads, and running lengthwise with the range of mountains. The metals contained in the now vacant spaces of these ravines, have been carried away and deposited below. The masses, thus broken and separated, have been still further reduced in the manner before stated, greatly diminishing the labor of mining. The deposits of detritus intermixed with gold may be the work of thousands of years; but the quantity may be estimated by the number and width of the natural cuttings through the gold seams now disconnected. It is certain that the amount of gold at the bottom cannot exceed the amount carried down from these original deposites. Without assuming that the amount of gold deposited in the Sierra Nevada is actually greater than in the same range further south, its peculiar geological and geographical character, may be a reason why gold may be found in California in greater abundance than in any other part of the world. It is found along this whole range from Sonora to Chili, although in greater or less abundance; and there is no doubt that a variety of other metals will be met with, perhaps as valuable, when the passion for gold washing shall have somewhat abated. It is remarkable that gold has been found almost invariably on the western or Pacific side of the great range, while silver, copper, and lead are discovered on the eastern side, and at a much greater elevation. It is probable that, instead of gold; silver and copper exist on the eastern side of the Sierra Nevada, towards the great Basin. What a field for the mineralogist!
But, by what process, or operation of nature, came these seams, or veins of gold or other metals, to be thus deposited? Was it by the agency of fire, or by water and alluvion? I think it probable that both may have been at work, being the two greatest solvents in nature, and, at the same time, the greatest chrystalizers. Perhaps metallic ores may be the work of alluvion, and the production of pure metallic substances—that of heat. With respect to gold, I think the latter theory is the more reasonable, as it is always found in a pure state, while the quartz (or pure silex) in which it is contained may be alluvial, and one pf the earliest deposites from the decomposition of the ancient unstratified mass. But where shall we seek for the original supply of the precious metal? How is it formed, or whence has it been extracted by the agency of heat? It is not enough to say that, like other metals, it is found diffused throughout all nature, for an appreciable quantity of gold has been extracted from violets. In my opinion, it exists on the original unstratified mass, in imperceptible proportions; but those proportions varying a different places, other metals being more or less abundant. The greater proportion of our soils, according to Sir Humphrey Davy, is formed by the decomposition of the original granite; and this accounts for diffusion of gold in minute particles, which may be taken up by plants, and enter into the composition of organized bodies. If then, the unstratified rock is the original seat of the metal, but in particles infinitely minute, it may have been separated by a very high degree of heat, by which it would be sublimated or volatilized, and thus carried upwards by chemicoelectric force, by a process resembling distillation. In this way, it would penetrate the quartz rock, or be condensed in the spaces of the laminated strata, such as the talc, schist, or mica slate. Such is the theory of Trimmer, Buchland, and other modern mineralogists. Lyall says—“granite, syenite, and those porphyries, which have a granite form structure, in short all plutonic rocks (rocks having undergone the action of heat) are frequently observed to contain metals, at or near their junction with stratified formations. On the other hand, the veins which traverse stratified rocks are, as a genera] law, more metalliferous near such junctions, than in other portions. Hence it has been inferred that these metals may have been spread in a gaseous form, through the fused mass, and that the contact of another rock, of a different state of temperature or sometimes the existence of rents in other rocks in the vicinity, may have caused the sublimation of the metals.”
One thing is certain, as may be at once seen by those who have examined the larger masses of gold brought from California, that the finer particles of gold have been run together, by a second operation of heat, sufficient only to fuse them and separate them from the quartz. The first was distillation, the second smelting, or rather simple fusion. It is possible that these great operations of nature have been repeated at different intervals, and different seams of quartz and gold, may be found in ascending the ravines; the lower, more completely scattered (but in finer particles) through the quartz, and the higher having afterwards undergone simple fusion.