Southern sentinel. [volume] (Plaquemine, Parish of Iberville [La.]) 1848-1858, 1849-11-21
USEFUL
ASSAYING

The assaying is the most curious and scienti-
fc Of all the business in the mint. The mel
tiers take the gold dust, melt it and cast it into q
bar, when it is weighed accurately, and a piece
is cut off for the assayer. He takes it, melts it
with twice its weight of silver, and several
times its weight of lead. It is melted in small
cups made OF bone ashes, which absorb all the
lead; a large portion of the silver II extracted
by another process, and the sample is then roll
ed out to a thin shaving, coiled up, and put in a
sort OF glass vial called a matrass, with some
nitric acid. The mattresses are put in a fur
mace, and the acid is boiled some time, poured
off, a new supply putin, and boiled again. This
is done several times, till the acid has extracted
all the silver and other mineral substances, leav-
ing the sample pure gold. The sample is then
weighed, and by the difference between the
weight before assaying and after, the true va
lue is found. All the silver over and above
five pennyweights for each lot, is paid for by
the mint at its true value. The gold, after L
has been assayed, is melted, refined, and being
mixed with its due proportion Of ALLOW, is drawn
into long strips, (not unlike an iron hoop fora
casko the round pieces cut out with a sort of
punch, each piece weighed and brought to right
size and put into a stamping press, whence it
comes forth a perfect coin.-Sciemifc Am.
-5@, CEMENT.
The best cement ever used for rough-coat
plaster on the outside of buildings, is made Of
clean, coarse, sharp sand, mixed two parts by
measure with one of good, ffesh-slacked stone
lime. If the sand is not entirely clean, put it,
in a tub or trough and stir it until every particle
Of clay and vegetable matter is washed out." ~
POLAR PLANT. m aF
The "rosin weed" (Sulpaium hciniatum,) OF
the western prairies, has the extraordinary pro-
perty Of pointing north and south. The cause
of its polarity has yet to be discovered. sa
ts $3.50 SEX OF EGGS. 1s09
1t is stated by a correspondent in the Lon
don Agricultural Gazette, that it is already
well known to every housewife in the north of
Scotland, and acted upon by them with uner-
ring success, that, before they set the clucking.
hens, the eggs to. be placed under them for in
cubation are carefully examined in the follow
ing manner The eggs are, one by one, poised
in the fingers of the left hand, with the broad
end uppermost, and in that position held close
to the light of a candle, orbefore a .brightssus;
the little finger'o of the right hand is then placed
behind the egg, near the top, family to shade
the light. When thus placed, and the egg
turned gently round, Gas Q stop would spin1a a,
hollow or vacuum about half an inch in dame
ter, will be distinctly seen, inside the egg.-
Now, if this hollow be- exactly on the top, the
egg will produce a cock; if on the side, it will
produce a hen. If the egg has ne such va
cum, or hollow, neither on the top nor side, Gas
is the case with all hens eggs where no cock IS
kept to fecundate, or i~mpregnate them) no one
in the secret would place any such under the
hen. for ipcnbation. nori in the hope of its hatch.
ing.-Am. Agricaatur1si. Wv RI
70 CLEAN KNIVES. s
Charcoal, ground to powder, is one OF the
best things ever used for this purpose.