A DELUGE OF GOLD.

New Zealand Mail, Issue 1264, 21 May 1896, Page 11

A DELUGE OF GOLD.

A FLOOD OF 'THE YELLOW METAL THREATENS THE WORLD. The world's production of gold fur 1805 was the largest since gold mining was begun. It was greater by a third than the highest yield of the “ bon-inz i " j ears ; greater by half than in the Comstock days ; greater by a uo/.en times than in any year down to the discovery of gold in California.

And this enormous total—amounting to more than £-10,000,000 -was due, not to the discovery of vast new fields,"not to rich “strikes," but to a single fact—cheapened production. Supplies at a low cost, improved methods of mining, and the new cyanide process, have brought within profitable treatment vast bodies of low grade ore, which formerly were looked upon as practically woithle.ss ; so that at the present time mum rock once thrown ■way or pissed by because i' con 1 lined hardly more than a microscopic shad nv of gold i.s used, and this has added to the gold production of the earth by quite onehalf, as that, production h.-s averaged in this general ion. Yet if six or eight years ago there had been an eemomixt or a st itistician bold enough to predict that by 1895 the gold supply of the world w mid be doubled his reputation would have been ruined. Gold nining was then on the decline. It has gone d-'Wn steadily t-iiice 1870, and there seemed m thing to bin ler a further decline. There came a world-wide mo/oment to close the mints of the chief commercial nations against silver, ami at the same time there seemed in o: aspect a universal scramble for gold. There came such a vast, and rap'd inere -so in tlm output of the yellow metal

as li ts Lein known hut once before in the hi.-.inry of the world In .‘-even years the gold supply ha-t risen from little over £'20,000,000 to £10,000,000.

Between the gold boom of IS 10-GO, and what may be likewise described as the gold boom of 1880 00, there lies this striking difference: The one was due to the accidents of discovery, the other to science and invention.

A quarter of a century has wrought a complete revolution in gold mining. Not only Itas placer mining largely given way to lode mining, but in the latter the methods in vogue bear little resemblance to those of no farther back than, say, 1870.

Two signal items in the line of progress have been the introduction of high explosives and improved drills. In 1870 dynamite was unknown. So was the compressed air drill. At that time it cost something like £3 in America to drift a foot in ordinary rock and ore. To day it coats leas than £l.

Twenty-five years ago the average expense of “stopping," that is, of getting out the ore after it had been reached by a

tunnel or shaft, was about 10s 0J a foot. To-day, it is in the neighbourhood cf 2s Gd.

The managerr out of a gold mine in this day is little short of an exact science, applied with rigid economy. With the old wasteful and expensive methods, it is safe to say that half the mines now in operation would not bo in existence. Along with improved methods has come a steady fall in the price of everything that enters into the working of a mine. Cyanide, chlorination, bromination, and other similar processes have taken the place of the old and extravagantly waste ful devices, and ores that yielded £2 a ton by amalgamation now return double the amount, while the expense of treatment is far loss.

The ordinary method of gold extraction, as almost everyone knows, is to crush the ore to a line powder and run tins over amalgam pi ites of quicksilver. 'The gold is precipitated upon the plates, and afterwards scraped off. But by this means even the best of devices only about half the gold values are saved. The rest goes oil in a kind of slime, which is known as “tailings."

It is here that cyanide comes into play. The “tailings" are gathered lip and deposited in huge vats, containing a weak solution of cyanide of potassium. This chemical has a peculiar allinity for gold, and takes it up, just as water dissolves salt or sugar. 'The gold is held in solution. 'The gold laden liquid is run through a kind of filter, made of bright zinc shavings, cut very fine. 'This precipitates the metal, and afterward, when the solution of cyanide has been run oil, these zinc shavings are put in clear water and thoroughly shaken, with the resalt that the gold falls off, and is deposited in the bottom of the tub.

Where ores are of low grade, they are nut {put through the stamp mills at ail, but are crushed to a line granulation and treated directly by the cyanide. It is fair to say that without cyanide there practically would be no South African goldfield.

But the new process lias not been always so succtsiful. In California, for example, it has so far been found of little value.

Our present gold basis currency scheme, originated in England in 1810, and subsequently adopted by the chief commercial nations of the earth, was formulated at a time when the world’s production of gold was a little more than £2,000,000 a year. In the interval that has elapsed, the world’s population has increased only two and a half fold, while its gold production has increased twenty times. The present indications are that it will be 80 times what it was in 181 G before this century is closed.

It is one of the curious and startling phases of the remarkable revolution in gold mining that it may force upon the nations the question as to whether they will he able to keep their mints open to the free coinage of gold at its present value. It is not a scramble for gold—it is a deluge which is threatened.-—From the Boston Globe.