-"The ore is crushed to a
certain fineness, depending on the character of the gangue. It is then
placed in leaching vats, with false bottoms for filtration, similar
to other leaching plants. A solution of cyanide of potassium and other
chemicals of known percentage is run over the pulp and left to stand
a certain number of hours, depending on the amount of metal to be
extracted. It is then drained off and another charge of the same
solution is used, but of less strength, which is also drained. The pulp
is now washed with clean water, which leaches all the gold and silver
out, and leaves the tailings ready for discharge, either in cars or
sluiced away by water, if it is plentiful.

"The chemical reaction of cyanide of potassium with gold is as follows,
according to Elsner:--

2Au + 4KCy + O + H2O = 2KAuCy2 + 2KHO.

"That is, a double cyanide of gold and potassium is formed.

"All filtered solutions and washings from the leaching vats are saved
and passed through a precipitating 'box' of novel construction, which
may consist either of glass, iron or wood, and be made in any shape,
either oval, round, or rectangular--if the latter, it will be about 10
ft. long, 4 ft. wide and 1 ft. high--and is partitioned off lengthwise
into five compartments. Under each partition, on the inside or bottom of
the 'box,' grooves may be cut a quarter-to a half-inch deep, extending
parallel with the partitions to serve as a reservoir for the amalgam,
and give a rolling motion to the solution as it passes along and through
the four compartments. The centre compartment is used to hold the lead
or other suitable anode and electrolyte.

"The anode is supported on a movable frame or bracket, so it may be
moved either up or down as desired, it being worked by thumb-screws at
each end.

"The electrolyte may consist of saturated solutions of soluble alkaline
metals and earth. The sides or partitions of each compartment dip into
the mercury, which must cover the 'box' evenly on the bottom to the
depth of about a half-inch.

"Amalgamated copper strips or discs are placed in contact with the
mercury and extended above it, to allow the gold and silver solution of
cyanide to come in contact.

"The electrodes are connected with the dynamo; the anode of lead being
positive and the cathode of mercury being negative. The dynamo is
started, and a current of high amperage and low voltage is generated,
generally 100 to 125 amperes, and with sufficient