Getting Gold

e gold was conveyed to them and deposited as a metal, it is necessary also to inquire into th

with a scientific argument to prove that such was not so, the idea was generally laughed at. I have lived to learn that these old hard-heads were nearer the truth than possibly they clearly realised, and that gold does actual

which adheres closely until worn away. This is a simple demonstration of a hydro-metallurgical process, though probably young hopeful is not

deed, there is sound scientific reason to suppose that in certain localities this is even now the case, and that in this way

, as also the gold dust gained from the beach sand on the west coast of New Zealand, or in the enormous alluvial drifts of the Shoalhaven Valley, New South Wales. Of the first, many fabulous tales are told to account for its being found in particular spots each summer after the winter floods, and miraculous agency was asse

al to accumulate in favourable spots; whilst on the New Zealand coast the heavy seas breaking on the shingly beach, carry off the lighter particles, leaving behind the gold, which is so much he

New South Wales drifts, is largely the result of the attrition of the boulders and gravel of moraines, which has thus freed, to a certain extent

d chloride. All of these are soluble and in the presence of certain reagents, also existing naturally, can be deposited in metallic form. Therefore, if, as is contende

solid siliceous lodes by glacial and fluvial action, and that the auriferous leads have been formed by the

d be found only at the very bottom of the drifts, if placed by water action, are sometimes found in all positions from the surface to the bottom of the "wash"? And, lastly, why is it that when an alluvial lead is traced up to, or down from, an auriferous reef, that the light, angular gold lies close to the roof, while the heavy ma

disposed of, but if not, it may be dismissed with the statement that the heat which would melt silica in the masses met with in lodes would sublimate any gold contained, and dissipate it, not in nuggets but in fumes. With regard to the assumed waterworn appearance of alluvial gold, I have examined with the microscope t

the decomposing agent, in order to imitate as closely as possible the organic matter supposed to decompose the solution circulating through the drifts, I first immersed a piece of cubic iron pyrites taken from the coal formation of Cape Otway, far distant from any of our gold rocks, and therefore less likely to contain gold than other pyrites. The specimen (No. 1) was kept in dilute solution for about three weeks, and is completely covered with a bright film of gold. I afterwards filed off the gold from one side of a cube crystal to show the pyrites itself and the thickness of the surrounding coating, which is thicker than ordinary notepaper. If the conditions had contin

iron sulphide changed to yellow oxide, the "gossan" of our lodes, and that though the gold was deposited, this occurred in an irregular way, and it was coated with a dark

e with the cracks open without any further alteration in size or form being apparent. Upon removing it a few days ago and breaking it open, I found that a large portion of the galena had been decomposed, forming chloride and sulphate of lead and free sulphur, which were mixed together, encasing a small nucleus of undecomposed sulphate of lead. The formation of these salts had exerted sufficient force to bur

used organic substances as the reagent to cause the deposit of gold on its base, and in each case these substances whether woodchips, leather, or even dead flies, were found to

d by these nodules, and that the metal thus reduced will be firmly attached to them, at first in minute spangles isolated from each other, but afterwards accumulating and connecting in a gradual manner at that point of the pyritous mass most subject to the current until a continuous film of some size appears. This being formed the pyrites and gold are to a certain extent polarised, the film or irregular but connected mass of gold forming the negative, and the pyrites the positive end of a voltaic pair; and so according as the polarisation is advanced to completion the further deposition of gold is changed in its manner from an indiscriminate to an orderly and selective deposition concentrated upon the negative or gold plate. The deposition of gold being thus controlled, its loss by dispersion or from the crumbling away of the sustaining pyrites is nearly or quite prevented, a conservative effect which we could scarcely expect to obtain if organic matter were the reducing agent. Meanwhile there is a gradual wasting away of the pyrites or positive pole, its sulphur being oxidised to sulphuric acid and its iron to sesquioxide of iron, or hematite, a substance very ge

eous formations after such formations had solidified. Some of the results were remarkable and indeed unexpected. I found that I could produce artificial specimens of aurifero

nd is from the "Transactions" of the Australa

OSITION

old was not probably existent in nature in any but its metallic form, therefore it had been deposited in its siliceous matrix while in a molten state, and many ingenious arguments were adduced in support of this contention. Of late, however, most scientific men, and indeed many purely empirical inquirers (using the word empirical in

ived from lodes but was nascent in its alluvial bed; and for this proof was afforded by the fact that certain nuggets have been unearthed having the shape of an adjacent pebble or angular fragment of stone indented in them. Moreover, no true nugget of any great size has eve

er. Moreover, the gold, which penetrates the stone in a thorough manner, assumes some of the more natural forms. It is always more or less mammillary, but at times, owing to causes which I have not yet quite satisfied myself upon, is decidedly dendroidal, as may be seen in one of the s

have extended they have proved this, that it was not essential that the silica and gold should have been deposited at the one time in auriferous lodes. A non-auriferous siliceous solution may have filled a fissure, and, after solidifying, some volcanic disturbance may have forced water impregnated wit

tone. Locality near Adelaide, now showing g

showing gold artificially intro

ing, now thoroughly impregnated with gold; the m

timony sulphide. In this specimen the gold not only shows on the sur

m Tarrawingee, in which the gold is deposited in spots, in appea

lies in this: That having found how the much desired metal may have been deposited in its m

the pyritous crystals on which it was formed while the interstices were filled with red hematite iron just as found in artificially formed nuggets on a sulphide of iron base. The author has a nugget from the same locality weighing about 1 1/2 oz. which exhibits in a marked degree the same characteristics, as indeed does most of the alluvial

ach other, were presumably dissolved from their salts and held in solution in the same mineral water, they would in many cases not be deposited together, for the reason that silver is most readily deposited in the presence of alkalies, which would be found in

re found so far from auriferous reefs, and also why heavy masses of gold have been frequently unearthed from among

certain of the earlier rocks comprising the earth's crust, and that its appearance as the metal we v