The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1858-04-05
SCIENCE AND RT.i
From the SclentllIc american.
SILVER AND IT'S Uses.

This metal possesses great interest. Its frequent
mention in the Scriptues-the shekes of silver and
the talents of sverndicaes its ancient use and ar-
plication as money. 1t is one of those metals,
which the alchemists of old termed 'noble metals,
because they found that it could not be rusted;
moreover, they could not dissolve it in any men
struum they possessed Fire only made it brighter.
Ausion is made to this fact in the book of Job, to
illustrate the triumph of good heart over misfor-
fortune. Silver is found in all parts of the world and
England yields its share. Bishop atson, of our
early chemical writers, says that the silver which
was procured from the mines in Cardiganshlre by
Sir Hugh Middleton, amounting to t2,0Oo val
ne per month, enabled him to construct that val
liable work which call the New River, for
the purpose of supplying portion. of London
with water. The bishop also mentions that
mint was established at Aberystwith for coin
ing silver In the English sd s mines this metal
separated by very simple process invented
by Mr.. Pattison, of Newcastle. The mixed
metal is melted in an iron pot, and is then al
lowed to cool. The silver "sets" before the lead
and is then separated by simply sraining it through
coander Silver can be beaten out into leaves so
thin that one grain of it can be made to sur
face gilmore than fifty square inches Wire also can be
drawn from it finer than human hair. In these
respects it has a resemblance to gold than
any other metal. With the mechanical qualities of
silver most reapers are pretty well acquainted; but
as very little is known of its chemical qualities it
may be well to mention them. Silver has, it
were, a determination to exist in other form
than in the metallic state which we generally
see it and although the chemist may dissolve it,
and overcome its ''nobtv, vet it is prone to as
sumo its natural state, that daylight will re-
store it to its pristine beauty tits here that chem
istry shows its great power in adapting peculiar
property of material to some use in the arts and
manufactures So we see that silver is the main in
strument in the Photographic art Silver is dis
sotS S@y your Sa' shadow is there indebiv printed
The poets may well liken Oft-fowing rivers to .s
yer threads covering the green velvet of the earth
but such types are prosy when we compare them
with the painting after life produced by sunbeam
on fabric imbued with silver. Again how carefully
the good housewife marks her linen! She well
knows how it is thus preserved for her own USE
but perhaps not of the fact that the indeli-
BILE ink is nothing more than the solution of five
cent piece, for which she willingly pays ten cents.
Sometimes little fungus takes up its abode the
human skim it grows very fast, but does not cause
much pain; nevertheless, it is insidious that if
not carefully watched it would destroy life. The
doctor comes, he rubs it over with little caustc
and health is restored. If you ask what this causc
Is called, the answer is 'nitrate of silver"
SEPrIMUs PIEssE.
INTERESTING PECULIARIrIEs OF DIAMoNDs-In Mr.
Milburn's valuable work on Oriental Commerce. he
gives some very interesting observations on the
peculiar characteristics Of rough diamonds Ac-
cordng to this writer, the color should be perfectly
crystalline, resembling a drop of clear spring
water, in the middle of which will be per-
ceived strong light, playing with great deal
of spirit. If the coat be smooth and bright, with
and seldom proves bad; but if there is a mixture
of yellow with green it is SOFT greasy stone, and
will prove bad. If the stone has a rough coat so
that the eye can hardly penetrate it. and the coat
be white and look as if it were rough by art and
clear of flaws or veins, and no blemish exist in
the body of the stone-which may be discov-
cred by holding it against the light-the stone will
prove good. If a diamond appears of green
ish bright coat, resembling piece of green glass;
inclining to black, it generally proves hard and sell
dom bad such stones have been known to have