present civilization is annihilated. Put them together in the hand of an intelligent and mighty nation, and that nation could recall the world from the chaos of barbarism. But they need each other, and it is in the wonderful combination of both, as well as the exhaustless abundance of each, that America finds sure promise of enduring power.

Thus East and West bear witness of our great inheritance of natural wealth. Every period of geological change has been laid under contribution to endow with rich legacies some portion of our land. Our territory epitomizes the processes of all time, and their useful results to man. Divided, yet in a stronger sense united, by mountain chains and mighty rivers, our diversified mineral resources may figuratively represent, as I firmly believe they will literally help to secure and maintain our characteristic national life, a vast community of communities, incapable alike of dissolution and of centralization; one, by mutual needs and affections, as the continent is one; many, by multiform industries and forms of life, as the members of the continent are many.

CHAPTER XX.

THE ORIGIN OF GOLD NUGGETS AND GOLD DUST.

The following article, from the pen of Mr. Andrew Murray, F. L. S., which appeared in 1870 in the London Scientific Opinion, corroborates forcibly the suggestions and opinions advanced in my last report (chapter lxi, page 449) upon the same subject. It is to be hoped that a hypothesis so highly probable as that of the solution, precipitation, and aggregation of gold in placers may be subjected to the test of careful experiments and comparisons:

The origin of gold nuggets and gold dust is not so simple or clear as at first sight it appears to be. The natural explanation of the production of gold dust is, that it is the golden portion of the débris of rocks, which have originally had gold disseminated through them. As the wear and tear of ages has crumbled into dust mountains so composed, part of the dust becomes sand, or quartz, or whatever else the basis of the rock may be, and the other part is the liberated gold, from which the quartz has been rubbed away; and if we accept this as the explanation of the production of gold dust, the same hypothesis should explain that of gold nuggets, which are found associated with it. But there are various circumstances which it is difficult to reconcile with this theory. One of these is the occurrence in the drift of nuggets of a larger size and less intermixed with foreign substances than have yet been discovered in any quartz reef; as most people are aware, the gold in reefs is usually disseminated in particles and strings through the quartz-veins or rock, instead of lying in pockets or masses. Another still more remarkable fact, applicable both to gold dust and gold nuggets, is that alluvial gold is generally of a higher standard than that obtained from the reefs. It is needless to say that if it is merely the gold washed or crumbled out of these reefs, it ought to be of identically the same standard and quality. Another objection to the dust being merely the degraded particles released from the rock, is the size of the particles-not nuggets, but particles of dust. Gold being so much softer than quartz, its particles, after being subjected to the same degree of attrition, ought to be vastly smaller. Although of greater toughness than quartz, and possessed of ductility and tenacity, which quartz wholly wants, it is very soft, and, under the influence of the attrition from running water and its accompaniments, ought to be pounded and torn into the minutest fragments; but this is not so. There is, moreover, a marked difference in the appearance of the gold dust from different drifts in different countries. In some it is like dust or sand, in others it is like scales. If subjected to the same influences in all, there seems no reason why the same shape should not obtain in all cases. These peculiarities would suggest that some other influence than mere degradation of gold-charged rocks has been the agent in producing gold dust; but in any and every view, we think it cannot be disputed that degradation must have had some share in the work. It is plain that if a gold-charged rock is reduced to gravel, sand, or powder, particles of gold, of some size or other, or gold in some shape or other, must form part of the débris. These gold remnants should be found in greater quantity, and in greater size, the nearer they lie to the source from which they were drawn, and this we believe also to be the case. The general similarity between gold-producing districts, by which a Californian miner could detect a likely spot for gold in Australia or Kildonan, probably depends rather on the character of the mountains out of which the gold has come than on the mode of production of the manufactured dust, if we may call it so. We imagine that the truth will be found to be that the result is referable to two causes, only one of which may in some cases have been present, in others, both. The first, the ordinary process of degradation and grinding the rocks to fragments; the other, as suggested by Mr. Selwyn, the government geologist of Victoria, that gold has also been taken up in solution by the water permeating the gold-bearing rocks, and that in passing through the drift, in which minute particles of gold lay, it has, from some cause, become decomposed, and the gold held in solution been precipitated and deposited around the most congenial nuclei presented to it, which would undoubtedly generally be the particles or pieces of reef-gold, or any other metallic substances for which it had an affinity.

We find an interesting paper on this subject in the Transactions of the Royal Society of Victoria, 1867, by Mr. C. Wilkinson, in which he mentions some facts bearing on the subject. It appears that Mr. Daintree, formerly of the geological survey of Victoria, had on one occasion prepared for photographic uses a solution of chloride of gold,

leaving in it a small piece of metallic gold undissolved. Accidentally, some extraneous substance, supposed to be a piece of cork, had fallen into the solution, decomposing it, and causing the gold to precipitate, which made a deposit in the metallic state, as in the electro-plating process, around the small piece of undissolved gold, increasing it in size to two or three times its original dimensions. Considering this accidental experiment of Mr. Daintree's as in some measure supporting Mr. Selwyn's theory, Mr. Wilkinson followed it up by a few simple experiments in the same direction, which he details in his paper. In his experiments a small chip of wood was generally used as the decomposing agent. In one instance he used a piece of leather. All through the wood and leather gold was disseminated in fine particles, and, when cut through, the characteristic metallic luster was highly reflected. From various experiments it would appear that organic matter is the necessary chemical agent for decomposing a solution of the chloride of gold in order to precipitate the gold as a coherent coating around a nucleus; and that, so far as Mr. Wilkinson had yet tried, iron, copper, and arsenical pyrites, galena, antimony, molybdenite, blende, wolfram, and metallic gold constitute essentially favorable nuclei to determine this chemical reaction. It is to be observed, too, that organic substances, such as fragments of wood, roots of trees, etc., occur abundantly in the gold drifts of Australia. If water holding gold in solution circulates through the rocks and drifts, all the conditions necessary for the production of gold dust and nuggets by deposit are present. Does the water so circulating now hold gold in solution?

One would think it would not be difficult for a chemist in Australia or California to determine the fact by direct experiment, but it does not appear that it has ever been tried. Mr. C. Wilkinson, however, quotes facts which lend probability to the view that when the trial is made the question will be solved in the affirmative. In testing a solid mass of iron pyrites Mr. Daintree found gold throughout. The mass retained the structure of a tree stem, in which the organic structure was replaced by pyrites. It had been taken from the Ballarat drift, and the same experiment was repeated by Mr. Newbury, the geological survey analyst, on another stem taken from the same drift, with a like result. Gold in such deposits assumes a mammillary form, which appears analogous to that presented by the surface of nuggets-a point of some importance, for, in the first place, it is a question whether a mammillary surface is the kind of surface that would be produced by abrasion and attrition; and, in the next place, abrasion or attrition can certainly have nothing to do with its appearance in these golden petrifactions. We cannot avoid attaching the greatest importance in relation to the question to the presence of gold in pyrites that has been formed in wood imbedded in auriferous drifts. The gold must have been in solution when so deposited, and everything will then depend on the age of the so petrified wood. If contemporaneous with the drift, the question is answered. Another fact to the same effect is, that sometimes gold incloses a nucleus of brown iron, etc. This is obviously quite inconsistent with such pieces of gold having been abraded, as they are out of crumbling rocks; such nucleated pieces of gold are never found in reefs. It is the old puzzle of a reel in a bottle. In relation to this we may remark that we believe that nuggets have never been found in the gold-fields of Brazil. We have the authority of Mr. Harding, a gentleman well known for his great practical knowledge of gold mines and mining in that country, that he never met with nor heard of a nugget, properly so called, in all his many years' experience in the gold district of Brazil; but, on the other hand, it is there almost invariably found in veins in connection with or in the vicinity of some other metal, generally iron. In what is probably the most prolific mine of gold that has ever been known in the whole world, that of San Juan del Rey, (the value of which was not long since so seriously depreciated by the accidental destruction by fire of the wooden ladders, supports, and machinery,) the gold is found in a matrix of porous iron or agglutinated iron sand, called Jacotinga, which consists of a bed or vein not a foot in width, but so incredibly rich that on one occasion, when our informant was on a visit to the manager, there was brought in on an assiette, as a sort of dessert for the eyes after dinner, a lump of gold ore that had been extracted that day from the mine. It was about the size of a large fowl; not so big as a turkey, but bigger than a duck. It was a mass of Jacotinga iron, with gold all mingled and streaked through it. The gold, when afterward extracted, was found to amount to 30 pounds weight. On the previous day the amount of gold obtained from the Jacotinga had been 67 pounds, and on the day following 130 pounds, equal in value to about £8,000. We only mention it as a corroborative instance of the concurrent presence of gold and iron. Lastly, as pointed out by Mr. Wilkinson, it must be admitted that the fact that gold may be greatly purified by dissolving and reprecipitating it, is very suggestive of the generally higher standard of alluvial over reef gold being due to a similar cause

CHAPTER XXI.

THE BULLION PRODUCT.

The difficulty of ascertaining the production of gold and silver in this country is peculiarly great, by reason of the lack of organized means and the extent of the field through which our mines are scattered, as well as the nature of the industry itself, and the motives which influence the minds of those engaged in it to withhold from publication the full and true account of its results.

When I entered upon my duties as commissioner of mining statistics I gave this subject careful attention. My predecessor had presented estimates of bullion production, involving confessedly a large excess over the amount actually accounted for by the statistics of either express shipments, exports and coinage, or the bullion tax. He had recommended the collection of accurate and comprehensive returns through resident agents in the mining States and Territories-a system which was not practicable then, and has not been practicable since, on account of the limited funds appropriated for the work. So far, however, as circumstances would permit, I have pursued the policy of obtaining from experts in different regions estimates of such portions of the production as were not covered by detailed and accurate returns, using, moreover, my own judgment, based upon extensive annual journeys of observation, in the modification of such estimates as I had reason to believe were without sufficient foundation. The elements entering into conclusions of this character are: the reports of production from single leading mines; the express shipments of bullion; the rates charged by express companies; the number of miners, white and Chinese, and the respective wages paid; the number and capacity of stamps running; the cost of mining and reduction, etc. The aggregate product of bullion thus obtained is of course merely a rude estimate. It has never been put forward as anything else, and I do not feel called upon to defend its accuracy.

As I committed the error of including my estimate of bullion in the introduction to my report of last year, which was set up and stereotyped several months before the last pages went to press, it does not agree with later estimates in the different chapters of the report. Thus Oregon and Washington are credited on page 7 with a product of $4,000,000; on page 205, their aggregate production is stated as $3,000,000. Again, Montana is credited on page 7 with $12,000,000; on page 317 this is corrected, and the cause of the error explained, while the product is cut down to $9,000,000, on the strength of later reports as to the effect of drought on the gulch mines.*

But all the excess of gold attributed in the introduction to my last report to Oregon, and more than a million of the excess in the earlier estimate for Montana, (made in September, and based on the product of the fiscal year, without foresight of the excessive drought,) belonged properly to California. For I have never been able to get direct returns from all the mining districts of that State. The attempts which have been made are detailed in a former report; and it is the experience of all who

*I declared (p. 317) that $9,000,000 seemed to me too small a figure. The surveyor general's official estimate for the year was $10,000,000. My investigations this year, however, corroborate the correspondent who sent me the smaller estimate.

have undertaken to obtain such information in California that the task is well-nigh an impossibility. The San Francisco press, noted for its enterprise in statistical matters, contents itself with presenting annually the receipts of the express companies, the coinage at the mint, and the shipment of bars, data which give, within a certain percentage, the amount of the precious metals received at San Francisco. I have usually deducted from this aggregate the amounts due to Arizona, Nevada, Oregon, Washington, Idaho, and Montana, (not the whole product of all these States and Territories, but the portion sent to San Francisco,) and credited California with the rest. That this gives a fairer result than could be obtained by a direct inquiry may be seen from the ill success of the assistant marshals under the Census Bureau, the aggregate of whose returns of gold product in California, submitted to me in January, 1871, was between $8,000,000 and $9,000,000 for the whole State, and for the whole of the year ending June 1, 1870.

Following the plan above mentioned, I obtained for California the sum of $20,000,000, which agreed with my own observations of the depressed condition of the placer mines in many districts, and of certain other causes operating to produce local diminution of product. But this estimate was too low, because the amounts subtracted for Oregon and Montana were too high. The table given in my introductory letter last year is therefore to be rejected, as contradicted by the later evidence of the body of the report. I regret that attention was not more distinctly called to this fact in the appendix; but the truth is, that I did not keep in mind, as the voluminous work passed through the press, the whole of those parts which had gone beyond my reach; and the corrections made upon later evidence, in the chapters on Oregon, Montana, etc., were introduced without proper regard to their bearing upon what had been said hundreds of pages before.

If the estimate of bullion product for 1869 had been the last instead of the first thing in the report, it would have been conformed to these corrections. I can now only introduce the corrected table as my estimate for 1869:

The term "all other sources," which I have retained from the reports of my predecessor, does not very definitely show the meaning intended. This item includes the product of precious metals east of the Rocky Mountains, and also a small margin of compensation for underestimates upon single States or Territories.

The following is my estimate of the product of 1870:

California

Montana

Idaho..

Utah

$25, 000, 000

9, 100, 000 6, 000, 000 1,300,000