afterwards located at Virginia City and elsewhere.

From our bricks a little corner was chipped off for the "fire-assay"--a
method used to determine the proportions of gold, silver and base metals
in the mass. This is an interesting process. The chip is hammered out
as thin as paper and weighed on scales so fine and sensitive that if you
weigh a two-inch scrap of paper on them and then write your name on the
paper with a course, soft pencil and weigh it again, the scales will take
marked notice of the addition.

Then a little lead (also weighed) is rolled up with the flake of silver
and the two are melted at a great heat in a small vessel called a cupel,
made by compressing bone ashes into a cup-shape in a steel mold. The
base metals oxydize and are absorbed with the lead into the pores of the
cupel. A button or globule of perfectly pure gold and silver is left
behind, and by weighing it and noting the loss, the assayer knows the
proportion of base metal the brick contains. He has to separate the gold
from the silver now. The button is hammered out flat and thin, put in
the furnace and kept some time at a red heat; after cooling it off it is
rolled up like a quill and heated in a glass vessel containing nitric
acid; the acid dissolves the silver and leaves the gold pure and ready to
be weighed on its own merits. Then salt water is poured into the vessel
containing the dissolved silver and the silver returns to palpable form
again and sinks to the bottom. Nothing now remains but to weigh it; then
the proportions of the several metals contained in the brick are known,
and the assayer stamps the value of the brick upon its surface.

The sagacious reader will know now, without being told, that the
speculative miner, in getting a "fire-assay" made of a piece of rock from
his mine (to help him sell the same), was not in the habit of picking out
the least valuable fragment of rock on his dump-pile, but quite the
contrary. I have seen men hunt over a pile of nearly worthless quartz
for an hour, and at last find a little piece as large as a filbert, which
was rich in gold and silver--and this was reserved for a fire-assay! Of
course the fire-assay would demonstrate that a ton of such rock would
yield hundreds of dollars--and on such assays many an utterly worthless
mine was sold.

Assaying was a good business, and so some men engaged in it,
occasionally, who were not strictly scientific and capable. One assayer
go