The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1902-07-29
REAL INNER MEANING
OF THE HALL MARKS
Indicate Not Purity, but Degree Of
Alloy Used in Making Article.

Every one who has bought a gold
ring or a silver chain knows what the
Hall marks are like, but few have a
clear idea as to whence they came and
what they mean. Many people imag-
Inc. that a sterling or STANDARD"
article is made of pure gold or silver,
but as matter of fact, it is necessary
to- mix with the precious metal GER
tain proportion of harder metal before
it9can be worked into articles of COM
merce.. This fact would open the way
to very easy and profitable frauds if
: the law did not make special provis-
ions for the protection of the pur-
chaser of gold or silver plate. The first
statute for this purpose was enacted
more than 500 years ago, and the main
principles then laid down are adopted
in most of the modern assay acts, viz,
that all gold and silver goods shall be
equal to certain standards, and shall
not be offered for sale until asSayed
and marked by the wardens of the
craft. An important act was passed
in the reign of Richard H., and as our
old lawmakers were not SO verbose as
their successors, it may be quoted YER
batim in a few lines: Because gold
and silver, which is wrought by gold
smiths in England is often times less
fine than it ought to be, because the
goldsmiths are their own judges, be it
ordained that henceforth every gold
smith puts his own mark upon his
work, and the assay of the touch be-
longs to the mayors and governors of
the cities and boroughs; with the aid
of the master of the mint, if there be
such, putting the mark of the city
or borough where the assay is" The
duty here assigned to the mayors and
governors has devolved upon the gold
smiths companies, and they have
Il Isl "a = ~ ca. ~
say offices, of which there are now
four in England, two in Scotland, and
one in Ireland.
Of these institutions, Birmingham
has by far the largest. In spite of
what some may say as to it's ancient
constitution, the Birmingham assay
office leads the way in improving the
process of assay. The establishment
of an assay office in Birmingham was
largely due to the efforts of Matthew
Boulton (the versatile partner of
James Waltz, who was one of the
chief promoters of the act of 1878.
There are thirty-six guardians, of
whom nine are representatives of the
trade, the rest being public men of such
varied types as Lord Norton and the
Right Hon. Joseph Chamberlain. They
are appointed for life, and elect the
wardens, of whom there are at present
five.
There are two alternative methods
for trying silver and two consecutive
operations for testing gold. In olden
times both metals were aSSayed by
simply rubbing the plate with a piece
of hard, black and smooth stone, and
Wetting the touched places with the
tongue, SO as to bring to light the va
rious tints which distinguish one quail
ity of precious metal from another.
This rough and ready method is still
used for certain purposes, but the
touchstone leaves too much to the
Judgment of the operator to fill the re-
quirements of the assay Office. The
process at present recognized by law
is known as "the dry way to distin-
guish it from "the wet way" So far
as 1t goes, the dry method is used for
both silver and gold. The lead-cover-
ed pill of precious metal is placed in
a small cupel of calcined bone, and
heated over a gas fire in an air furnace
of an improved pattern, designed by
Mr.. Arthur WeStWood. When all the
silver has been dissolved the pure gold
left in the platinum cupel is so brittle
that it has to be annealed before it can
be weighed to tell how much silver has
been extracted from it. BY comparing
the weight of the pure gold with the
original five grains you get the pro-
portion of gold to allow in the man
ufactured article.
This new process is much quicker
and surer than the cupellation which
has been explained, and it is gradual
ly superSeding that method. A certain
weight of the silver to be assayed Is
dissolved in nitric acid by heat, and
solutions of iron and salt are added
| by means of finely graduated pipettes.