calls upon the Stockholders for a prompt payment of the assessments, so that the operations may not be impeded by want of funds. It is but justice to say that the assessment of 15th June has been promptly responded to. Much will be done during the winter to develope the mine. Every thing at the present time looks promising, and although your Directors are fully aware of the uncertainty of the early stages of mining operations, they cannot but feel much encouragement in the prosecution of this work. By order of the Directors, JAMES T. WATERS, Secretary. JOURNAL OF SILVER AND LEAD MINING OPERATIONS. THE SILVER MINES OF CALIFORNIA. The fame of the silver mines of California is quite as ancient as the knowledge of its gold placers, and it is the opinion of gentlemen well informed in the matter, that ere many years shall elapse, we shall see the business of silver mining take high rank among the mining interests of the State. So far as discoveries have been already made, the presence of silver seems to be chiefly confined to the Central and Southern portions of the State, and there can be little doubt but that when the mountains of that portion of the State are thoroughly explored, silver ore will be found as abundant, and perhaps as rich as in the most favored regions of Mexico or Peru. We gave some two or three weeks since, from the "Monterey Sentinel," an article with regard to the silver mines of Monterey county, from which it appears that there are not less than six distinct views of silver on one ranch in that county, and it is also stated by those who are well acquainted with the silver mining districts of Mexico and Peru, that a remarkably close resemblance exists between those regions and the Sierras of Monterey. Rich placers of both gold and silver, were known to exist in Monterey county more than fifty years ago, and were worked to some extent, though in a very loose and unskilful manner. The priests of those days invariably discouraged the search and working for minerals, as a matter of policy to themselves; hence the loss of the particular knowledge with regard to their location and extent. Sufficient however is known to warrant the conclusion that the mines were both extensive and valuabls. Silver ore in Monterey county was so plenty and so easily obtained about the close of the last century, that it was frequently used for making bullets-the mineral being a mixture of lead and silver, the silver formning about twelve per cent. of the mass. The most reliable evidence also exists with regard to silver mines on or near King's river, near the head of the Tulare valley. Other veins are known to have been worked to some extent in Santa Barbara county. It is also known that there are valuable veins of silver ore in Calaveras and Tuolumne counties. One of the veins in Monterey county on the Alizal ranch, the one from which it is supposed the early Californians obtained the material for making their bullets, is said to have been re-discovered and worked for a short time by a Mexican in 1831, who finally abandoned it on account of a dispute about the proprietorship. From that time it remained undisturbed until 1852, when a party of German miners, who had but little experience and less capital, again took it in hand, but for these two very sufficient reasons soon gave it up again. They wrought it sufficiently, however, to prove that it would be valuable, under proper management, with a sufficient capital. Two more veins have since been discovered in the same immediate neighborhood, which present every indication of being extensive and valuable. From the facts which appear to be authentic, and the accuracy of which might be thoroughly tested by inquiries and examinations, in the neighborhood alluded to, there would seem to be very little doubt of the truth of the assertion put forth in the commencement of this article, that the business of silver mining must become a very important branch of California industry. In order to bring about this result, it is desirable that the first operations should be undertaken by experienced managers. A mine of either gold or silver, which might be made extraordinarily productive under an experienced and liberal management, may, under the control of inxperienced managers, although with an abundance of capital, fail to yield even a paying return. It is therefore to be hoped that the first experiments in silver mining in California, will not, as has been too frequently the case in gold mining, be intrusted to incompetent hands. It is desirable that the attention of enterprising capitalists and practical miners may be turned toward this promising interest. The occupation of silver mining has ever been in all countries, more productive and certain than that of gold. There is at this time a great demand for silver, both as a circulating medium and for the arts; and it will be most fortunate for California if she should find it in her power to supply this deficiency. With gold and quicksilver in abundance, and inexhaustible supplies of all the grosser minerals, we need now but an equal development of the argentiferous ores to make us, as a nation, independent of the world, in every thing which relates to money and commerce. With this end in view, we shall endeavor to collect and lay before our readers, from time to time, such facts as we may be able to obtain with regard to the discovery and the proper methods of working silver mines. We shall close this article, the length of which, nothing but its importance will justify, with the following paper, by Guido Kustel, translated for the San Francisco Chronicle from the "German Journal" of that city: "Silver mining will become a much more important interest in the future f California than at present, because it is beyond doubt that the mountains, particularly in the southern part of the State, contain many silver mines. owever, the discovery and digging of silver ores are more difficult than those of gold. Silver is less widely diffused, and in many of its forms is not easily to be recognized. Gold is easily discovered, on account of its dissemi nation in gold districts, and of its striking appearance, unless in combination with Tellurium or Molybdenum. The pan soon tells the gold miner what he can expect. A gold vein is almost the same to him as a quarry vein. When he seeks the one, he seeks the other. When he finds the quarry he can easily know whether it contains gold. But it is different with silver. It is true that in a small plain in Peru pure silver was found just below the surface of the soil, and was found clinging to the grass roots on the sod, but that was really a silver placer. Pure silver has likewise been found in thin leaves, in connection with some ores of iron; but generally its natural state is in an ore. He who would seek for silver ore, should examine the geological formations of stone, which will often furnish information of what is to be expected. The extraction of silver from the ore requires an exact knowledge of the nature of the metal and of the substances in connection with which it is found in the ore, before the miner can decide upon the best method of handling his material. Nearly every silver mine yields, besides the ore, a mineral which is too poor to be directly worked up, and yet too rich to be thrown away. A good method of working is almost indispensable. In some quartz mines of Mariposa county, a glittering red ore, rich in a clayish silver, appears with the gold, but for the want of a good working process, it is left to the wild flood. The melting, however, is applicable to silver ore only under peculiar circumstances. Amalgamation is more usual and cheaper, but it is tiresome, and the ore must, in most cases, be previously roasted with comman salt to prepare it for amalgamation. The new methods of obtaining silver from copper ores are of much impor tance, because they are much cheaper than amalgamation. One is called Augustin's method .Where there is chloride of silver he casts it into a strong solution of common salt, and the solution dissolves the silver, which is then precipitated with copper. For this purpose a peculiar form of copper (cement kupfer,) which is obtained by precipitating it from a natural solution of sulphate of copper with the aid of iron, is used. The other method is Ziervogel's, and is grounded on the fact that oxide of silver is unaltered by a certain degree of high temperature, which changes sulphate of copper and iron to oxides. By wasting oxides of silver with the sulphate of copper or iron, the sulphuric acid leaves the baser metal and joins the silver. The sulphate of silver is then dissolved in water and precipitated with copper. By this method only from five to eight per cent. of silver is lost, and it is undoubtedly the best method in use. The specific gravity of silver is 10.50. It is found in a state of nature pure, in combination with sulphur alone, with sulphur and other metals, with chlorine alone, with iron, with antimony, with arsenic and antimony, and seldom with iodine, bromide, or quicksilver. Silver ores are found almost exclusively in veins in gneiss, mica, graywacke, and clay slate, and sometimes in greenstone, transition limestone and the latter limestones. The veins are principally of quartz, hornstone, lime and brounspar, barytes and fluorspar. WASTE OF SILVER IN ROASTING ORES. SIR-The observation in your last Journal, giving the result of elaborate and well-digested experiments of Prof. Plattner, on the roasting of silver ore, per se, together with amount of loss of silver in the treatment of various grades of ore, when mineralized by various substances, demands the most serious attention of all parties interested in the treatment of silver ores; or those who may be interested in silver mines. Prof. Plattner, as you are aware, is a gentleman of world-wide reputation in metallurgical pursuits; and any observations emanating from his great and varied experience are worthy of our highest consideration, and the more especially as we now import such a quantity of dry silver ores from South America, and other countries, as well as many of our leading capitalists being interested in silver mines abroad, at which the ores are, in some instances, treated either by means of amalgamation or smelting; in either case roasting the ore is a necessary operation. I am advised that Prof. Plattner will continue these experiments, in order to arrive at a sound practical conclusion thereon, which is much to be desired. Many years since I had the benefit of Prof. Plattner's personal instruction; since which I have been extensively engaged in the treatment of silver ores, both at home and abroad, by smelting and amalgamation, I believe of all the known classes of silver ores. And being subject in such treatment to the losses described so clearly by Prof. Plattner, I will with your permission, sir, shortly allude to some treatment of ores which I adopted in order to lessen such loss; and I must here regret that I have mislaid some tabular formula which I adopted, and found to answer to a considerable extent in treating ores of different percentages of silver, mineralized by different substànces, or alloyed by various other minerals. It was a table I had prepared for my own use, as I was largely interested in the purchase of silver ores at that time; the loss of this table, or form of treatment of ores, as well as indisposition, prevents me at present from going as fully into the matter as I could desire, in order to be understood; and I must remark, that to treat ores properly, a careful and complete chemical analysis must be made. Now this is too little understood, and too little practised, to expect that every person engaged in the treatment of silver ores can by any possibility know how to treat the ore placed in their charge for reduction, so that you see primarily our ignorance must produce great loss; and secondly, the difficulty of reconciling the prac tical treatment with the chemical analysis, needing every attention, care, and closely observed practice. Why, sir, your Journal has teemed with remarks on the treatment of gold quartz, while the subject of silver ore treatment is far more worthy the attention of the scientific man, as involving close research. Gold results in mechanical treatment, silver into that of chemical manipulation, and in its combinations with nearly all the common metals and minerals, in a variety of forms and states of mineralization. The silver ore imported into this country is large in amount of tonnage at present, and is on the increase, yielding in some cases not more than 30 ozs. per ton, and running up from that ley to several thousands of ounces per ton. These ores may be said to be competed for by two or three houses only; there are a number of bidders, but their offers are so short of the real value, that they excite a smile from the more knowing ones, who generally purchase to advantage. I have known the offers to vary as much as 95 per cent. per ton of ore, and they excuse themselves in making these offers on the ground as shown in Prof. Plattner's experiments-viz., loss in treatment; that they are never able to obtain any approach to the assay product in treating the bulk, and that they offer accordingly to keep themselves safe, or, in other words, to perpetuate their own ignorance. The silver ores imported are treated by amalgamation, or by smelting. Their amalgamation is conducted after the usual process, by mixing common salt in quantities (generally having a reference to the percentage of silver contained in the ores); a mixture is thereby effected which, on being roasted, the silver in the ores undergoes a chemical change, which converts it into chloride of silver from its previous state of mineralization. It is then requisite, either in barrels, or by other means, to bring it into intimate contact with mercury. The quantity necessary of quicksilver also depends on the percentage of richness for silver, which is taken up by chemical affinity in the form of amalgam, aided by using scraps of iron, and, in some cases, a little lime. Now, in this process, roasting the ore is the great hinge on which the success of the treatment depends; hence the importance of Prof. Plattner's experiments. The other process is that of smelting, but the silver ores are generally roasted per se, and afterwards mixed in varied proportions with ordinary lead ores, which both act as a flux and take up the silver, which is subsequently obtained by desilverizing the lead in the ordinary way, the roasting loss occurring as a matter of course, alluded to by Prof. Plattner. Now, sir, in my practice in amalgamation of silver ores, I obtained the best results from using 12 per cent. of salt for ores containing 100 ozs. of silver per ton, increasing or diminishing that quantity as the richness or otherwise of the ore for silver warranted, using about 650 lbs. of mercury per ton of ore, as I always found an excess of these menstrums to be attended with benefits in practice over and beyond the chemical formulary of theory, adding some scrap iron and a little lime for some classes of ore. In the roasting of silver ores for smelting I always used a little salt, the quantity entirely depending on the character and extent of the mineralization. Now in theory, the salt would be found to form a chloride of silver; in practice it does no such thing-that is, if you do not exceed a certain limit, which is to be ascertained by an analysis of the ore treated as to the quantity of sulphur, arsenic, or other matter it contains; and by the use of salt in roasting I found a very manifest benefit of results. I fear that I have trespassed too much on your valuable space with my crude remarks, but must hope some others more competent will give us their views on a subject of great interest to the trade of this country. My bodily indisposition prevents me from giving all the details I could wish in this communication, but I would like to see our School of Miners imitating Prof. Plattner.-London Jour. ART. MINING MAGAZINE, EDITED BY WILLIAM J. TENNEY. CONTENTS OF NO. III., VOL. VII. ARTICLES. PAGE 30 THE IRON MANUFACTURE OF GREAT BRITAIN-THEORETICAL- II. MINING STATISTICS OF GREAT BRITAIN 147 150 IV. DIRECTIONS FOR COLLECTING, PRESERVING AND TRANSPORT- 174 JOURNAL OF MINING LAWS AND REGULATIONS. Decision of the Supreme Court of the United States, in the Suit between the Minnesota and National Mining Companies 184 [COALS AND COLLIERIES. A Visit to the Lackawanna Coal-Fields 188 Opening of a New Coal Road from the Barclay Coal Fields to the Susquehanna 125 |