THE quickest attained, if not the most permanent, source of national wealth is doubtless to be found in the development of the precious metals of a country where they exist in profitable quantities. All the other exchangeable results of labor have their value much reduced by costs of transportation, or by the state of the markets where they must be sold. If the labor yield corn or cloth, it must bear the tax of distance, the impost of foreign duties, and the variation of demand ; if it yield gold beyond the cost of production, none of these drawbacks weigh upon it in an appreciable way. It is therefore natural and fit that among all the resources of a new country men should first attend to the precious metals, and that the gold and silver hunter should have been the pioneer of civilization, — the greed of gold the very wind in the sails of the explorers who have broken down all the barriers of distance and difficulty that the earth sets against commerce. The nature of his work, giving as it does neither food nor clothing, draws in his train all the firmer elements of society, and so brings about the rapid subjugation of wildernesses. Moreover, as the explorer for gold must combine skill, judgment, and courage with a strong body and determined will, he makes the best possible beginning for civilization. With all his faults he is necessarily the manliest of rough men, — the fittest material to face the difficulties of a wilderness, and to lay therein the strong foundations of states to be.
So the future of the precious metals in this country is interesting not only with reference to the sources of quick and stimulating wealth, but also from the point of view of political development. The immense area of our Cordilleras of North America, nearly one third of the national domain, a region greater than the empire of Germany, is to be shaped into the uses of society by the power of this peculiar branch of human industry. Left to all the other impulses that lead men into infertile lands, this section would have waited for centuries, an untenanted desert, and would have become a refuge for outcast populations, such as tend always to regions where subsistence is too scanty to make the basis of an agricultural community. We have but to see the actual effect of this search for precious metals in this region to become convinced of its great political importance. It is therefore a worthy task to try to foresee the future of the preciousmetal production of the United States, and to determine, as far as such determinations are possible, the probable importance of this form of industry in the various parts of the country.
The fields of the precious metals in the United States may be generally divided into two principal areas, that of the Appalachian and that of the Cordilleran range. Besides these there are the smaller regions, which may be termed, in a similar fashion, from their neighboring mountains, the Laurentian, including the region about Lake Superior, and the Ozark region about the mountains of that name in Arkansas and Missouri. There are lead ores in several of the States of the Mississippi Valley, at great distances from these mountain ranges, that contain a small proportion of silver, but in few cases does this silver exceed about the four or five thousandth part of the ore; nor is there any chance that they will ever produce tins metal in quantities of the least commercial importance. The whole of the rich agricultural region of the Mississippi; the whole of the Western plains, through all their extent to the one hundred and second meridian west from Greenwich, and on their northern section to the one hundred and tenth meridian ; the whole of the low-lying plains of the Southern States, in all containing a little over one half the total area of the United States, but at least nine tenths of its arable land, is sure never to prove productive of any of the metals now known to the arts, save iron, lead, and aluminium; and of these lead will never be again economically produced there, until the mining industry of the Cordilleran region begins to wane.
This rejection of the larger part of our national area from the list of regions where gold and silver may be found in profitable quantities is based upon actual experience of the generations grown up within the area, as well as the general fact that the experience of other countries shows us that such rocks as underlie this region are always marked by the absence of gold and silver in profitable quantities.
Of late years there has been a great advance towards a clear understanding of the natural processes by which metallic deposits are brought into the shape in which the miner finds them. All the old notions about the outburst of mineral veins, by fiery ejection from the deep interior of the earth, have been cast aside. Geologists now pretty generally recognize the fact that all our metals are deposited in our stratified rocks as they are laid down on the sea-floor, having been separated from the sea-water, as a great part of all the rocks are, by the action of sea-weeds and marine animals. In this disseminated form, but in varying degrees of richness, all our metals may be said to exist in all our rocks, but in a state so diffused that nothing but the most careful analysis by concentration of a great mass of the rock would enable the chemist to recognize their presence. In the larger laboratory of nature, where work is done more patiently than man can do it, this concentration is readily accomplished. It needs only the application on a large scale, and for a long time, of the same much-heated waters the chemist uses in his processes to strip a bed of limestone of its gold, silver, or other ores, and to bear them to some other part of the neighboring earth crust. In the machinery of our hot springs and geysers, we have at once the whole of the mechanism necessary to remove the metals from their original positions in the rocks, and fill fissures with the material. Recent investigations have shown that the hot springs of the Rocky Mountain region are to-day making deposits of gold-bearing vein-stones in their fissures. The rain-water passes downwards through the rocks of the hills, until it is heated in its course and compressed under the weight of the water above; restrained from passing into steam by this pressure, its heat often becomes much greater than that of boiling water, as is proved by the behavior of the geyser. As it creeps through the rocks it takes up the metallic substances with which it comes in contact, but as its power of holding them depends mainly upon its high temperature, the water must perforce lay them down as soon as in its upward course it has lost a large share of its heat; and this loss of temperature occurs as the water rises through the fissure towards its point of discharge. Some part of its transporting power is given to the water by the various gases it takes up in its course, — gases produced by the decompositions it brings about. These gases are held in the water by pressure, and escape as it comes to the open air, and to a great extent leave it as soon as it approaches the surface. Thus we see that there are peculiar conditions that limit not only the occurrence of gold and silver in rocks, but the concentration of that which is thus contained into such a shape that it may be profitably won. These conditions are, essentially, that the metals shall first be deposited in the rocks; then that more or less heated waters shall penetrate the rocks for a sufficient time to dissolve out the disseminated minerals and accumulate them in fissures.
The degree of heat necessary to effect this work differs widely in the case of different substances. Water at the ordinary temperature will effect the concentration of lime, and give us veins of calcite or gypsum. At the same or a very little higher temperature, we will have lead carried into fissures, or into the porous parts of rocks. Silver begins, in small quantities, to move towards the veins along with lead in waters that are but slightly thermal. Gold appears to require a higher temperature for its transportation, or at least some conditions that are rather less often presented than those that bring about the concentration of the baser metals.
The result of these conditions is that the area over which we find lead ores in profitable quantities is very much greater than that of silver-bearing rocks, and the area occupied by silver lodes is larger than that of gold ores, — in part, at least; for the reason that the conditions necessary to the concentration of these substances are less and less favorable in the order in which they are named. There is no doubt, also, that the aggregate amount of these substances separated from the sea differs widely, and that the amount of lead obtained by the heated waters in passing through rocks is greater than silver, and the silver is greater in quantity than the gold. This latter is the most widely distributed of these metals, though the quantity present in rocks is usually very small. Almost any sea-beach or clay bank will probably give a chemical trace of gold, at least on a little concentration; but silver and lead are not so widely distributed, in the metallic form. This more general presence of gold is due to the fact that it is not easily oxidized, and so endures the wear of time that reduces the other ores to atoms and bears them away to the sea.
Another noteworthy feature connected with the distribution of the precious metals is that while they are generally found together in the same districts their relative abundance differs very widely in different regions. As yet there have been few attempts to determine the laws fixing the respective quantities of these substances, and it is likely that they are to a great extent involved in facts that have yet to be ascertained. There are, however, some very general conclusions to which we may come, from overlooking the whole field, which will aid us a good deal in forecasting the future of the mining industries of the different sections of this country. First, as regards the occurrence of gold, we may say that, leaving aside for the moment the gold that occurs in recent deposits of sand and gravel near river-courses, gold deposits are generally found in our older slates, schists, and granitic rocks, while silver more frequently occurs in close relation to limestones, especially when they have been brought in contact with masses of lavas. From this it comes about that the especially gold areas of the United States are separated from the areas that are peculiarly rich in silver. On the eastern side of the continent, in the Appalachian Mountain system, we have an almost uninterrupted gold field from Nova Scotia to Alabama; on the western face of the continent, separated at certain points from the coast by a range of mountains, but yet essentially bordering on the sea, we have an other similar but much richer field. In the middle part of the great Cordilleran system, from the Sierra Nevada eastward to the plains, lies the wonderful silver belt whose stores of wealth are beginning to pour their tide into our markets.
The Eastern field has very little silver mixed with its gold, and this little is grouped in a small region in New England lying between Boston on the south and Mount Desert on the north. In all the rest of the field, though there has often been a clamor about silver-bearing veins, no considerable deposits of this metal have yet been found, or are likely to be discovered hereafter. On the other hand, deposits of gold are wide-spread, and have yielded largely to the most shiftless methods of work at half a dozen local districts within this belt.
In the California coast region the silver element is perhaps more conspicuous ; the gold itself is more mingled with silver than in the Atlantic district, but there have never been any profitable silver mines in the region west of the Sierra Nevada, nor are there likely to be. As we come east from California the gold element persists, though in diminished quantity, in the veins, but a larger share of silver is evident as soon as we get east of the Sierra Nevada. The Comstock lode, the most famous mine of the century, and perhaps the most wonderful of all mines, shares equally in the two precious metals. Yet further to the east the silver element in the mines seems steadily to increase in importance, and although the gold maintains its place it is relatively of much less value, and is probably on the whole of less richness, than in the California district. When we come to consider the detrital deposits or placer gold mines of this district, we will have a better basis for conjecturing the future of the gold industry in this region.
The gold mines of North America and the smaller deposits of silver-bearing ores, like those in the Appalachian field, do not differ in any important way from similar deposits in other countries; but when we come to consider the great silver lodes of the Rocky Mountains, we find some conditions that, while they are not without precedent in other lands, are at least so far peculiar that they deserve a place quite by themselves. It was long ago remarked that certain silver lodes were formed near where masses of igneous rocks had been thrown through fissures in the earth in the form usually termed dykes. This was especially the case where ancient lavas were driven through limestone rocks, but in all European experience such veins are of exceptional character and not peculiarly remarkable for their richness or magnitude. When, however, the fields of the Cordilleras began to be studied they gave evidence of the existence of numerous deposits of this character, but on a scale far more gigantic than anything that had been observed on the other side of the sea. The first of them to be discovered was the Comstock lode, a great ore deposit formed at the point of junction or contact of several different kinds of lavas. But none of these lavas are in contact with limestones, as in the case of some of the great lodes we have next to notice. Within three years there have been half a dozen or more similar lodes discovered, of less but still of remarkable richness. At Leadville, after men had mined placer gold about it for nearly twenty years, it was suddenly found that the rusty-looking lumps that had been a well-cursed nuisance in their sluice-boxes were rich silver ore, and that the great lode they came from was on the hill-side just above the stream. A few months’ work was sufficient to reveal the most extensive and easily accessible mass of silver ores ever opened on the continent. In the two subsequent years many thousands of shafts were opened in search of the lode, and somewhere between fifty and one hundred of these found their way to the ore. From these workings it is easy to make a general determination of the character of the lode. Although it presents us with an amazing variety of detail, it is pretty clear that we had here, in the first place, a wide, sloping field of bare limestone rock, such as may now be found on many a desert mountain side in this district. The surface of this rock was worn by running water and in dented by atmospheric erosion, as is the way with such rocks when long exposed to the air. At length there came down the slope, on a sudden rush, a tide of lava, scores of feet in depth, that filled up all the irregularities of the rock and buried its surface deep beneath the fiery stream. After this flow of lava had ceased, or possibly during its movement, the adjacent surfaces of the limestone and lava moved on each other, so that the faces of both were scratched and scored by the attrition. This movement seems to have resulted in the formation of an irregular crevice separating the two rocks from each other to such an extent that percolating water could pass along the line of contact. There were chambers and fissures of various forms created, and into these cavities the heated waters carried their store of metals. At certain points the fissures were abundant, many great rents being formed in the trap rock ; just such as we may now observe in the lavas on the flanks of existing volcanoes. At other points the limestone was penetrated by old cavities worn on its surface while it was in the open air, or excavated by heated water after its burial beneath the lava. Into these various pockets the filling of ore was laid, apparently with great slowness, some qualities of ore being put down at one time and some at another. While the actual point of contact between the limestone and the lava is the place where the most of the ore has been laid down, some of the richest “ bonanzas ” seem to have been formed at many feet away in the lava, in caverns made at the time of the eruption or at a later date. Not every part of the contact between the two rocks is mineralized, nor is there anything like a uniformity of the richness of the ore when found. Sometimes the lime rocks lie together, with no “pay ore” between; again, the the ore is nothing but an oxide of iron; attain, there may be pockets of silver ore containing from ten to twenty thousand ounces of silver to the ton of ore. In this indescribable variety of materials we see the result of many geological periods, during which the heated water crept along this path; now favoring the deposition of one substance, and now another ; sometimes taking away the deposits of a former period, and replacing them by other compounds. After all this work had been done, in the later stages of the country’s history these rocks were thrown from their original attitudes and rent by rifts and folds; so that it is very hard to tell which way the old lava flowed, or the steepness of its original bed. Nor do we yet know the existing area of the deposit; but it is likely that much of its surface has not yet been discovered. So far, this is, I believe, the only case yet observed of a mine occurring where an extensive sheet of superficial limestone has been overflowed by a lava deposit; but there are a number of other cases in the Cordilleras of North America where limestones have been inclosed within very massive intrusions of lava, and in every such case I believe there have been found similar contact veins. At the Horn silver, the Bassick, the Silver Park, and other mines where lavas come in contact with limestone we find in the plane of contact similar deposits of silver-bearing ores. Mining experts are already using these facts as a basis for prediction of the value of prospects, and miners looking for locations are now searching along the lines of contact of this description, it is not too much to say that wherever the massive lava intrusions or overflows lie in contact with limestones we may expect in most cases to find a mineral-bearing lode.
This determination has an especial importance from the fact that the Rocky Mountains are peculiarly the seat of lava eruptions of this nature. For some reasons mountain ranges differ greatly in the amount of volcanic action that has taken place in them. The Alps and Apennines are almost destitute of lavas, and their continuation in the Caucasus are similarly wanting in these products of internal heat. There is some reason for believing that east and west mountains yield less lavas than those running in meridional directions. Be this as it may, the fact remains that the North American section of the Cordilleras singularly abounds in lavas, and is relatively rich in limestones ; so that this combination, which experience has fairly proven to be favorable to the formation of lodes rich in silver, may be expected to occur very often in this vast field.
There is another circumstance that is likely to prove favorable to the rapid extension of the silver-producing industry of this region. Owing to the small rainfall which for geological ages has characterized the Rocky Mountains, the surface of the greater part of the region west of the Sierra Nevada is singularly destitute of soil ; the different beds and veins of rock are disclosed almost as clearly as they would be in a stone quarry. In no other country has the prospector such a chance as is given him here ; the earth lies open to his inspection ; indeed, it invites his eye to its treasures. In other mineral-bearing countries the explorer has to work blindly, taking the chance exposures of the rocks that the streams may give him, or delving beneath the soil for the trace of the lodes. Here nature lays everything where he can easily find it. The result will be that the immediate future will give a very rapid extension of our knowledge of the ore-bearing lodes of the Rocky Mountains, and this combined with the great business and mechanical skill of the American miners will doubtless lead to a very swift development of their resources. It should also be considered that these lodes are in many cases exceedingly favorable for the rapid mining of their treasures. That at Leadville, for instance, is so nearly horizontal that it can be assailed from hundreds of shafts, and its treasures stripped within a few years ; in many other cases the lodes run through high mountains, so that one or more thousand feet of their depth may be approached by a system of tunnels, without the need of hoisting or pumping machinery, those evils that beset most mining. Moreover, in the majority of these mines, the trouble from water is likely to be small. The low rate of rainfall throughout this area, though it is a damage to its best interests by making agriculture almost impossible, is helpful to the miner. There are countervailing evils in these conditions. Timber, which the miner must have for his underground works in large quantities and of the best quality, — for on it his life as well as the safety of his works depends, — is scarce and reproduces itself slowly if at all, so that eventually it will have to be brought from great distances at much cost. The fuel necessary for smelting ores has also to be carried from the world beyond the mountains. That now used at Leadville comes from Pennsylvania, and though there is a chance that coals fit for such uses will be found nearer, there will always be trouble from this cause. Moreover, the fact that this whole region is essentially unfit for agriculture is vastly to its disadvantage. Hay is now worth more than flour in a large part of Rocky Mountain camps ; last winter it was sold at about one hundred and fifty dollars per ton in Leadville. The rapid extension of railways will do much to bring this region into connection with the food-raising lands of California and the Mississippi Valley; but there are now thousands of lodes known in this region which would be exceedingly productive in Europe or the Atlantic States that will not yield a profit, considering the cost of food and fuel on the barren fields where they lie.
We have not considered the vast body of so-called true " fissure ” silver-bearing veins of this region, — those where the rents are not in contact with limestones, and thus do not possess the peculiarly favorable conditions that this contact seems to bring. Their name is legion ; indeed, they are innumerable. Many of them have established themselves as productive mines, but none of them have yet won a fame comparable to that enjoyed by several of the great contact deposits; yet being much more numerous than the contact deposits, they will doubtless in time come to have at least an equal share in the production of silver. Only a very small part of them have proved profitable ventures for mining, and these probably do not as yet contribute more than ten millions of dollars per annum to the silver supply, despite the fact that they have been the objects of search for a score of years past.
There yet remains another and an obscurer class of veins which is even more peculiar to the Rocky Mountains than the contact deposits. This class includes several very extensive mineral deposits in limestones or limy beds, where the ores are lodged in caverns which have all the complications of structure proper to ordinary caves. So far these caverns containing ores have been found in but three or four localities. The most noteworthy are those at Eureka, Nevada, the Emma mine, of unhappy memory, and those in Southern Utah, near the town of Frisco. These mines have an exceedingly irregular character, and are in a certain respect the most untrustworthy of all mines ; yet when, as in all these cases, the chambers are large, the deposits rich, and the bed of rock in which they are excavated is extensive, the miner may hope to find one after another of these depositaries of ore. There is, as might be expected, always a channel that connects the rooms of the cavern, and by following this the explorer, as in a superficial cavern, may hope to find his way from one enlargement of the cave to another, indefinitely. It is very often difficult to separate this class of mines from certain groups of fissure veins ; yet there can be no doubt that it exists, and, though similar structures are found elsewhere, that it is essentially peculiar to the Cordilleras of North America. It is reasonable to suppose that these caverns owe their origin to the streams of heated water coming from the depths towards the surface. If we look about the mouths of many of the hot springs that abound in the Rocky Mountains, we perceive great masses of lime that have been brought up from below. Besides what the spring leaves at its mouth, it bears away a larger share of the same substances to the rivers. In this work it must excavate very extensive caverns. A slight change of conditions would probably lead to the filling of these excavations with ores brought in by the heated waters, and so give us caverns containing a store of gold or silver ores, or perhaps, as in the caves of Frisco, a mixture of the two metals,
If the Rocky Mountains had been worn down to their roots, as have the ridges of the old Appalachian chain, these caverns would have been to a great extent destroyed; for they can be formed only quite near the surface, owing to the pressure of the overlying rocks, which would force their walls together at great depths. To this relative freedom from erosion in the Rocky Mountains is due, also, much of the richness of the contact deposits. The caverning action of heated waters has probably aided in the formation of the great Leadville vein ; and the whole deposit as far as yet explored lies so near the surface that a relatively small amount of wear would have destroyed it altogether. It is reasonable to suppose that there are other deposits of the same nature in this region which have owed their preservation to the small amount of wear that has occurred there.
Between the Sierra Nevada and the eastern front of the Rocky Mountains there are doubtless many gold-bearing lodes; but none of them have proved very remunerative save the exceptional Comstock lode. It is to be noticed, however, that the gold element seems to increase as we come further eastward, and in the Black Hills, a singular outlier of the Cordilleras, rising far out on the plains beyond the main range, there are more profitable gold mines than have yet been found in the great belt of country that makes up the central regions of the Rocky Mountains.
There is still another source of gold supply to which we have not yet turned our attention, namely, the deposits of surface gold formed during the wearing down of the rocks, and deposited in the soil or in the river gravels and sands.
It happens that gold is the least destructible of all our metals, unless its kindred metal, platina, be the more enduring against the agents of decay. So that while the gold-bearing hills have been sinking down under the action of the frost and rain, losing, perhaps, hundreds of feet in their height, the gold escapes the waste, and, being heavier as well as more enduring than all other substances, clings near by its original place, while the other elements of the rocks have traveled to the farthest seas. The gold that occupied the rocks that lay a thousand feet above the level of the present mountains in California and Colorado in greater part lies in the soil or in the river sands between the hills and the sea. To this immovability and imperishability of gold is due its early adoption as a precious metal; for all the gold of early days was obtained from alluvial deposits by processes of washing analogous to those of modern days.
Every region that has ever produced gold in considerable quantities has given a large share of this superficial gold; and many regions where the lodes have never yielded gold at a profit have produced placer gold in large quantities. A conspicuous case of this nature occurs at Leadville, in Colorado. In the California Gulch, where Leadville lies, over six millions of dollars were taken out in the early days of placer mining, but no one has ever found the lodes whence this treasure came. It is likely that here, as in many other regions, the gold is derived from a great number of small lodes, which individually would not pay for mining, but collectively suffice by their decay to furnish a large amount of gold to the river gravels.
It happens that human wit was never so turned to gold hunting as it has been in California; so we naturally enough have there the most skillful methods of robbing the earth of its gold. California now contributes more placer gold to the world’s supply than any other district; we may say, perhaps, than all the others put together. But there are many other regions in the United States where in time the same destructive industry will come to do its work. There is reason to fear that there are some hundreds — if not thousands — of square miles of territory in the Appalachian gold field where the “ giant ” of the hydraulic miner will soon be making its havoc. The most innocent-looking heap of gravel, wherein the uninstructed may look for years without finding a trace of gold, may still contain the small amount of gold that pays the miner to sweep it away into the rivers. There has been as yet nothing like a search of the Appalachian gravels, and the hydraulic process is in use only at a few points in the Carolinas and Georgia. But there are half a dozen districts on the eastern flanks of that chain where there is sufficient proof of the existence of placer gold in profitable quantities. The valley of the Chaudière in Canada, and the valleys of the Dead and Sandy rivers in the adjoining district in Maine, and several of the tributaries of the Merrimac and Upper Connecticut, are likely fields for this form of work. Indeed, there would be a certainty of extensive workings in some parts of those districts, were it not for the difficulties which would come from the damage done to the streams by the gravel that would be thrown into their beds. But in time it will doubtless be found profitable to work these places, at the same time protecting the streams from the waste gravel, as can almost always be done.
When we get south of the Potomac, the regions promising the large production of gold by washing are very extensive. I am inclined to believe that a larger amount of gold will hereafter be obtained in this way than has ever been taken from ordinary mines in this Southern gold district. Not only along the borders of the streams may this Southern placer gold be found, but at many points the hill-sides in their slow decay have left the gold beneath the soil, while the rest of the wasted rocks have dissolved out and been carried to the sea. In the northern regions the ice of the last glacial period destroyed the results of this slow accumulation of earlier times, so that it is only near the rivers that we get any stores of superficial gold ; but as this work did not extend below Washington, we have in this unglaciated country the slow concentration of gold where gold veins have decayed. Some of these masses of auriferous earths cover hundreds of acres of hill-sides, and are so rich that steam is being used to force up water to wash them away.
In the Rocky Mountains there are many river valleys that have shown a great abundance of placer gravels. All the rivers that head up about the source of the Arkansas are bordered by placer deposits, that await the systematic mining that large capital alone can give them. The prospectors report gold along the banks of scores of rivers within the Cordilleran chain; but the capital necessary to apply the costly Californian hydraulic system is large, — much larger in most cases than is necessary to open ordinary mines; and there are none of the speculative chances in the venture that lends such a charm to vein deposits. The yield is slow, sure, and definitely measurable; and though often large cannot compare with the chances of bonanza mines. It is only in California, where the conditions are perhaps not more favorable than in many other regions, that hydraulic mining has become a great industry, and has begun to carry the destruction to the rivers and the earth that it will, if unchecked, in time bring to many other lands. Not only are the vigilant gold hunters of the Pacific belt washing away and flooding with waste the borders of their streams, but they are following the beds of the ancient rivers beneath the sheets of lava that have blocked their courses, and finding great deposits of gold that have been stored away in what seemed perfect hiding-places.
Whoever looks over the whole field of American precious-metal mining will be convinced that this industry is certain to make a very rapid growth in what is left of this century. He will also come to the conclusion that the production of silver is destined to increase very rapidly for a score or so of years to come, provided the demand for this much slandered metal does not fall too far short of the supply. Beyond a brief term this yield of silver will surely diminish, especially if there is any considerable lowering in its price. The observant eye can also see that the production of gold is likely to be extended to many new fields, and that the yield of this metal is in the future likely to be rather more steady than that of its bulkier sharer in the greed of men. North America and the twin continent on the south are doubtless to be the great producers of precious metals in the future; their store of silver must be of greater value at the present price of this metal than their store of gold. If the world continues to use silver in the coming century as it has in the past thirty centuries, there is a fair prospect that our continent will win some thousands of millions from its silver-hearing lodes. Even if we make what seems to me the mistake of using gold alone as a basis of exchange, the production of this metal will no doubt give us a larger mining industry than any other country can expect to gain.
N. S. Shaler.