The morning news. [volume] (Savannah, Ga.) 1887-1900, 1895-11-30
How Ores Are rested.

Helena Dispatch to Boston Transcript
To the uninitiated but observant
stranger who Wanders UP and down ih
the labyrinth of shafts and tunnels, dig
gings and dumps of a genuine mining
camp perhaps there is no subject more
full Of interest than the process 10y which
a lump of brown ore, which, TO his ir-
experienced eye, looks not in the least
attractive, is made TO yield its shart Of
silver and gold; or the means and meth
DDS by which the mining man at his side
so confidently assures him that a ton Of
that ore will go o2.3S ounces IN silver aad
$l7. So in gold.
Even the eastern mining expert, or
graduate from some mining school will
wonder how in the log cabin or pine
shanty destitute of all the elaborate
paraphernalia to which he has been ac-
custOmed. these results are so readily
and accurately obtained.
AS a general rule the majority Of the
ores, except those containing the preciut.
metals, for purposes of purchase ana
sale are valued accorQipg to the cost
of mining and shipping, 50 that, except
for melallurgical purposes, II, is uuneees-
sary TO seek TO determine with mucn
accuracy the contents and value of suCa
In the case of ores rich Ia the precious
metals, however, it is entirely different,
as in their purchase and sale, both par
ties, the buyer as well as the seller want
to ascertain accurately and to a certain
ty the value of the entire lot The meth
DDS by which this knowledge is Obta inci
are 50 simple as to sbeseasily understood
and practised by many a man WlD does
not know the tecnnicaf symbols OF The
metals he is determining, or could not
give a scientific exposition of the process;
but, nevertheless, I'm his line, he IS IN
accurate and successful assayer.
When a quantity of ore is to be sampled
for assaying it is first broken by an or
binary rock crusher into pieces the size
of an English walnut, after which Ii Is
shovelled back into the car, but in such a
manner that every fifth shovelful is thrown
aside by itself the remaining four-fifths
being finally taken away. This fifth por-
ton, known as the sample" is then re-
duced to a much greater degree of fineness
by means of Cornish rolls. 1t is then piled
on the floor in a cone, fattened out, and
opposite quarters are then removed. The
remaining quarters are then thoroughly
mixed, and again piled in a cone, dattened
and quartered; this operation being re-
peated until the sample is reduced to 100
pounds. 1t Is then weighed repeatedly. for
Of moisture contained in the ore which
in some ores, especially those of the con-
centrates is so considerable as to make
very aDpreciable difference in the weight
The moisture is then expelled, and the ore
is crushed to such a degree of fneness
that it can be passed through a sieve con-
tanning 100 holes TO the linear inch. The
sample Is next put up IN small glass bot
ties which are sealed with sealing-wax
and then stamped, for the purpose Of pre-
venting the possibility OF their being
opened or tempered with without detec-
ton.
The above Is the process OF samDling
used among the mines, and the sample Is
now ready TO be assayed but only "a small
portion OF n will be used among for that
purpose, and the quantity generally taken
is what is known as an assay ton"