The Placer herald., 1858-10-16
Valuable Discovery,

A French gentleman of San Francisco
Mons. L. Rolf, communicates the following
letter to the Phare:
Editor Of the Phare: At this moment,
while the world is in extacies, SO to speak,
at the most brilliant application of electrici-
ty, Providence has likewise permitted me to
make new and fortunate application of the
same principle. If have alone arrived at
that termination which the first chemists of
Europe proposed to reach. | nevertheless
should not take to myself the entire credit
of this discovery; for it was the results OBJ
tanned by Monsieur Recquerel, that induced
me to launch out into unknown tests. bv
which | have arrived to positive solution.
Honor then to him! honored be he who has
pointed out the way, for | am free to confess
that | am but the student, cleaning the pro-
ducts of great master
Since 1886, labored researches had been
made to extract silver from its minerals by
electro chemical process. Mons. Recquerel
proved, that by Transforming each mineral
to a salt of the same metal, its reduction to
metallic state could be obtained by electri-
city. But the results of his process were
deducted from causes purely chemical, which
had been long known, while the obstacle
which prevented the employment of his
method on large scale, was the enormous
expense for acids, joined with the difficulty
of operating outside the laboratories.
Despite the numerous experiments made
in France, England and Germany, on miner
ais from Mexico, Peru, Columbia and Altai,
despite the satisfactory results obtained bv
Messrs. Recquerel and Dupont St. Clair they
were obliged to abandon the operation on
large SCALE on account of the expense sur
passing, or at least equalling the yield Of the
minerals 1t was then attempted to make,
economically, a double transformation from
the rough ore, and it is to this point that
Providence has successfully led me.
Employing electricity as the only reducing
agent, | have been able to separate from the
SILICA or quartz, not only the pure gold, but
likewise all the oxydes, such as sulphurets,
chlordes and others, and this, he it under
stood, without melting, without amalgama-
ton, but simply by an electro-chemcal ope-
ration, which does not last over twenty to
twenty-five minutes.
TO give you an idea of the results obtain
ed by means of the electric fluid, it will
suffice to state that Mr., II. w Walker sent
to me some quartz tailings which had been
submitted to several successive tests by anal
gamaion, according to the ingenious spiral
system Of Mr.. Russ, and from these tailings
| extracted, after these gentlemen believed
that there was not another particle of gold
left to collect from them, in the space of
twenty-five minutes, such quantity Of gold
that the average yield was equal to that from
quartz mines considered to be rich | made
four essays increasing each time the quantity
Of mineral, and the yield in each case sur
passing my most sanguine hopes.
| propose in another letter to discuss in
few words the inevitable causes which pro-
duce the loss of gold, when submitted to the
methods now in vogue. For the present, |
am satisfied to inform you of the incalcula-
ble usefulness Of process as simple as it is
cheap, the expense being scarcely worth
mentioning, and above all, the vast improve
ment this discovery will make in quartz
mines, now considered poor, but which are
really and incontestibly Of great richness.
have the honor to salute YOU