Cañon City record., 1897-11-18
The Handy s Me6ee Mercantile co.
JOHANNESBURG GOLD.
The City Built on the Precious
Metal.
Yet the Knowledge of the Assay1st
ls Necessary. IL IL said, to De-
ternine Its Exact Lo-


1t is comomnly said that johannes
burg is built on gold; it might be as
truly said that it is built on science, or,
in the concrete,on cyanide OF potassium,
1 reckon that one-third of the work
able mines, possibly one-half, arc now
shut down or unopened; but had it not
been for the Macarthur Forrest cyan
is!e process--discovered just ten years
ago-50 per cent. of the workings still
omen would be closed. From first to last
the extraction of gold is a matter OF
chemistry. The visitor to mineralogi-
cal collection has seen specimens of ore
with glittering flakes or crystal grains
OF the precious metal. A well-known
Canadian geologist was once taken to !,
mine. and on the strength of the sheen
OF splendid ore on the side walls of the
mine passages he gave a certificate of
the richness OF the workings. The
sparkling nuggets had been placed
there. and the renown of the professor
suffered somewhat. You may traverse
the underground ways of Johannes
burg for miles without seeing CLEAN
of what the miners call visible" II is
the assayist who tells us there is gold.
and with refined modern methods he
can say exactly how much; but, so far.
it passes the wit of man to get it all
oui. When lump of ore is brought to
the surface. if it contains any gold at
ali it is rarely more than one grain in
2e-0e0. oftener one in $4,000. The first
thing to determine is whether there is
any likelihood of any of the metal. For
this purpose there has lately come into
pretty general use the sorting process.
What is wanted is the congIomerate.
the rock. known as reef. with quartz
pebbles and fiinty cement The rest is
waste.
was pleased at the Celdenhuis Deep
TO see that the Kaffirs were Intelligent
enough TO separate the wheat from the
chaff. The rough stone passed before
them on revolving table. and they
conid at once distinguish by inspection
the Jumps of quartz or sandstone that
were no good; though. as have said,
there is not from one weeks end to an
other scintillation of gold 10 guide
them This done the remaining ore is
crushed in steel mortars by metal
stamps or Pestles weighing over 100
poands each. They pound the stone so
exceedingly small that it flows out in
thin stream of muddy water through a
screen with meshes numbering roo 10
200 per square inch. Night and day these
ponderous stamps are grinding to this
minnteness quartz, pebbles. pyritic iron
and fiinty cement that have for untold
ages been buried like misers, embrac-
ing their treasure deepi in the rocks. All
the rest is pure chemistry. The soapy-
lacking wafer flows over copper plates
frced with quicksilver. Man himself is
not more eager than this element to
Clutch the precious metal. and before
the liquid has flowed a foot the mercury
has laid hold of all the free gold. The
two forman amalgam. and the mercury,
being easily rctorted off by heat. can
be used again and again. But the
mercury has tallen out only about one
hals the gold. TEe other half is locked
in the embrace of pyritic iron and other
base materials, and from these it is set
frcc ny The use of chlorine gas. which
has an atiinity for gold. and the cyanide
OF potassium. which causes the grains
OF metal fioatiug in the soIusion TO pre-
ciIitase aud attach themselves TO zinc
sh:yings. Roughly speaking. the mer-
cary captures 90 per cent. of the gold.
chlorine -. ard The cyanide IS per cent
There is still left in the shines 10 per
cent. more or less uurecovered
In the conrse of the year there
must 6e at leas, e75oo0o worth
of bullion thrown away on the
Wi,watersrand Treatment of the
shines uuw in progress is saving f-ac-
tion of. this amount The Crown Reef
gel Lice ounces out OF the refuse last
month. but some of 1t viii always be
lost This waste of man is nothing to
The waste b, nature. The reefs that re-
main are a mere patch. probably. TO
those that once existed. They are what
is left after ages of denudation. But
enough remains. MIR. Rudd recently
stated that before the century was out
the Rand might be producing bullion
for 2o,o0o.o00 sovereigns per annum.
Near as we are to 1900, the estimate is
not eNsravagant- When the rich deep
levels get NIL TO work the effect will be
enormous. London Telegraph,