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Thus when the varnish is bruised, it is
the gum that turns white and the
color is restored by the oil & [and] turps.
If the mixture is left on the furniture
it becomes tough and cannot
be removed. To varnish old
furniture, it should be rubbed
with powdered pumice stone and
water to take off the old surface
and then varnished with new
varnish reduced by adding turps.
Apply with a stiff haired brush.
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For moths in furniture see the
Scientific American August 2, 1873
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"Mineralogy Explained"
The minerals which are not scratched
by the knife are seldom of any value
as ores.
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Ores of metals are usually heavy
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Effervescence with acid indicates
a carbonate, and frequently limestone.
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Iron ores are dissolved in warm
acid after being pulverized
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Gold can only be dissolved in
"Aqua Regia"
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Iron Pyrites heated on charcoal before the
blowpipe gives of sulphuries [sulphuric] acid
fumes and forms a magnetic Globule
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Copper Pyrites are of a darker or Brass
yellow Color, not so hard as Iron
pyrites and dissolve in Acid with a
green or blue color
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"Tests for metals"
When "gold" is dissolved in "aqua Regia"
the solution should give a purple color
with protochloride of tin solution, Gold
is also precipitated by sulphate of tin [struckthrough]
solution [struckthrough] Iron as a brown powder
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"Silver" dissolved in nitric Acid gives a
white precipitate with hydrochloric acid
which pricipitate is soluble in Ammonia
Mixed with Carbonate of Soda and
heated on Charcoal before the blowpipe
compounds of silver give white
brilliant metalic globules
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"Lead" also gives a white precipitate
with hyrochloric Acid, but it dissolves
in boiling water, with bichromate of
potash or iodide of potasium, a
beautiful yellow precipitate is formed.
Its compounds a very readily reduced
on charchoal. Galena often contains
silver which can only be seperated
from the lead by an assayer
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"Zinc" and Tin are quickly reduced
by the blowpipe
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"Iron Ore" Hemetite" hardness 5 to 6
Scratches glass, not easily scratched with
a knife, Color steel gray to Iron Black.
Streak cherry Red or Reddish Brown
When heated on charcoal in Reducing
flame, becomes magnetic, soluable
in muriatic acid.
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"Iron Ore Magnetic", 72 per cent Iron -
When rubbed on unglazed porcelain
leaves a Black streak.
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