218 THE DIAMOND MINES OF SOUTH AFRICA
ores,
for the precious metal was so extremely minute that it floated away
with the water, and, at no considerable depth, a portion of the gold
was held in the pyrites, and could not be recovered by means of the
ordinary process of amalgamation. Some other process was needed that
would save the minutely fine gold which became suspended in the water
owing to the attachment of globules of air. When the Rand was
discovered, no such process had been developed beyond the experimental
stage. MacArthur and Forrest, of Glasgow, were experimenting with a
solution of cyanide of potassium, which was known to be a solvent of
gold. They found that the ores from the Rand readily yielded their gold
when treated by this process, which soon came into general use. This
was the saving of the Rand, for without such treatment only a few of
the richer mines would to-day be paying properties.
A
little more than a year after Robinson bought properties on
Witwatersrand, the despised " cabbage field" of the Lang-laagte farm
was floated with a capital of £450,000, and yielded £950,000
in gold in the next five years, with a profit of nearly seventy-five
per cent in dividends on the par value of the capital stock. The
holdings of the Robinson Company, in the same time, produced over £1,400,000 in gold and paid .£570,937 10s. in dividends to shareholders.
*
By the discovery of the diamond mines in Griqualand West, a product ranging over £80,000,000
in value in less than thirty years had been added to the meagre output
of South Africa, and the gold mines of the Witwatersrand began, about
seventeen years ago, to swell this great exhibit of the mineral riches
of the land by the addition of gold already aggregating over
£100,000,000.
The annual flow from the diamond mines has averaged, for years, over £4,500,000
in value and the Rand has greatly outstripped even this rich showing.
Prior to the discovery of diamonds, the total tally of South African
exports and imports combined was not £6,000,000 in value. In 1898 it
was nearly £50,000,000, and, of the total exports, eighty per cent were mineral products.
