scientific secrets-第9节
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In a pint of spirits of wine dissolve 2 oz。 of seed lac； and 2 oz。 of
resin。 The principal use of this polish is for the carved parts of cabinet
work； such as standards； pillars； claws； &c。 It should be laid on warm；
and it will be still better； but all moisture and dampness should be
carefully avoided。
132。 FRENCH POLISH
Take 1 oz。 of shellac； 1/4 oz。 of gum…arabic； and 1/4 oz。 of gum copal；
bruise them well； and sift them through a piece of muslin； then put them
along with a pint of spirits of win into a closely corked vessel； place it
in a very warm situation； and shake it frequently every day till the gums
are dissolved； then strain through a piece of muslin； and keep it corked
for use。
133。 WATER…PROOF POLISH
Put 2 ozs。 of gum benjamin； 1/4 oz。 of gum sandrac； and 1/4 oz。 of gum
anima； into a pint of spirits of wine； in a closely stopped bottle； place
the bottle either in a sand bath； or in hot water； till the gums are
dissolved； then strain off the mixture； shake it up with a 1/4 of a gill
of the best clear poppy oil； and put by for use。
134 FINISHING POLISH
Put 2 drachms of shellac； and 2 drachms of gum benjamin； into 1/2 pint of
the very best rectified spirits of wine； in a bottle closely corked； keep
the bottle in a warm place； and shake it frequently till the gums are
dissolved； when cold shake up with it 2 teaspoonsful of the best clear
poppy oil； and it will be fit for use。 This polish may be applied with
great advantage after any of those mentioned in the foregoing receipts
have been used。 It removes the defects existing in them； increasing their
lustre and durability； and gives the surface a most brilliant appearance。
135。 COMPOSITION USED IN WELDING CAST STEEL
Take of borax； 10 parts； sal…ammoniac； 1 part； grind or pound them roughly
together； then fuse them in a metal pot over a close fire； taking care to
continue the heat until all spume has disappeared from the surface； when
the liquid appears clear； the composition is ready to be poured out to
cool and concrete； afterward being ground to a fine powder。 To use this
composition； the steel to be welded is raised to a heat； which may be
expressed by bright yellow； it is then dipped among the welding powder；
and again placed in the fire until it attains the same degree of heat as
before； it is then ready to be placed under the hammer。
136。 COMPOSITION USED IN WELDING CAST IRON
Take good clear white course sand； 3 parts； refined solton； 1 part；
fosterine； 1 part； rock salt 1 part； borax； 1 part； mix all together。 Take
2 pieces of cast iron； heat them in a moderate charcoal fire； occasionally
taking them out while heating； and dipping them into the composition；
until they are of a proper heat to weld； then at once lay them on the
anvil； and gently hammer them together； and if done carefully by one who
understands welding iron； you will have them nicely welded together。 One
man prefers heating the metal； then cooling it in the water of common
beans； and heating it again for welding。
137。 CAST IRON CEMENT
Take of clean borings or turning of cast iron； 16 parts； of sal…ammoniac；
2 parts； and flour of sulphur； 1 part； mix them well together on a mortar；
and keep them dry。 When required for use； take 1 part of the mixture； and
20 parts of clean borings； mix thoroughly； and add a sufficient quantity
of water。 Note。 … A little grindstone added improves the cement。
138。 CASE HARDENING
This is the conversion of the surface of wrought iron into steel； for the
purpose of adapting it to receive a polish； or to bear friction； &c。 The
best method in the world of effecting this is by heating the iron to
cherry red in a close vessel； in contact with carbonacious material； and
then plunging it into cold water。 Bones； leather； hoofs； and horns of
animals； are best for this purpose； after having been burnt or roasted； so
that they can be pulverized。 Soot is very frequently used； it answers； but
not so well。
139。 TO SOFTEN IRON OR STEEL
Either of the following simple methods will make iron or steel as soft as
lead： … 1。 Anoint it all over with tallow； temper it in a gentle charcoal
fire； and let it cool of itself。 2。 Take a little clay； cover your iron
with it； temper in a charcoal fire。 3。 When the iron or steel is red hot；
strew hellebore on it。 4。 Quench the iron or steel in the juice； or water；
of common beans。
140。 SOLDER FOR LEAD
Melt 1 part of block tin； and when in a state of fusion； add 2 parts of
lead； if a small quantity of this； when melted； is poured upon the table；
there will； if it be good； arise little bright stars upon it。 Resin should
be used with this solder。
141。 SOLDER FOR TIN
Take 4 parts of pewter； 1 of tin； and 1 of bismuth； melt them together；
and run them into thin slips。 Resin is also employed in using this solder。
142。 SOLDER FOR IRON
The best solder for iron is good tough brass； with a little borax。
143。 SOLDER FOR COPPER
Take of brass； 6 parts； zinc； 1 part； tin； 1 part； melt all together； mix
well； and pour out to cool。
144。 SOLDER FOR STEEL JOINTS
Silver； 19 parts； copper； 1 part； brass； 2 parts； melt all together。
145。 HARD SOLDER
Fuse together 2 parts of copper； and 1 of zinc。
146。 SOLDER FOR SILVER
Fuse together 5 parts of silver； and 1 part of brass。
147。 GOLD SOLDER No。 1
Take of gold； 4 parts； silver； 3 parts； copper 1 part； and zinc； 1 part。
148。 GOLD SOLDER No。 2
Take of gold； 3 parts； silver； 3 parts； copper； 1 part； zinc； 1/2 part。
149。 GOLD SOLDER No。 3
Take of gold； 2 parts； silver； 3 parts； copper； 1 part； and zinc 1/2 a
part。 The gold； silver； and copper must be fused in a crucible before the
zinc is added； or else you cannot keep them in the vessel while heating。
When all are completely fused； they must be well stirred； and run into
bars。 Solder No。1 is for gold 16 carats and upwards； No。2 is for that 14
carats fine； and No。3 for lower qualities。 If more zinc is added； it will
fuse at a lower heat； but the colour is not so good。
150。 MOCK GOLD
Fuse together 16 parts of copper； 7 of platinum； and 1 of zinc。 When steel
is alloyed with 1/500 part of platinum； or with 1/500 part of silver； it
is rendered much harder； more malleable； and better adapted for all kinds
of cutting instruments。 Note。 … In making alloys； care must be taken to
have the more infusible metals melted first； and afterwards add the
others。
151。 BRITANNIA METAL
Take 4 parts of brass； and 4 parts of tin； when fused add 4 parts of
metallic bismuth； and 4 parts of metallic antimony。 This composition is
added at discretion to metallic tin； according to the quality you wish to
make。
152。 BLANCHED COPPER
Melt together 8 parts of copper and a half part of arsenic。
153。 COMMON PEWTER
Melt together 4 parts of tin and 1 part of lead。
154。 BEST PEWTER
Melt together 100 parts of tin and 17 of antimony。
155。 A METAL THAT EXPANDS IN COOLING
Melt together 9 parts of lead； 2 of antimony and one of bismuth。 This
metal is very useful in filling small defects in iron castings； &c。
156。 QUEEN'S METAL
Melt together 9 parts of tin； 1 of antimony； 1 of bismuth； and 1 of lead
157。 IMITATION PLATINUM
This metal； or alloy； very closely resembles platinum。 Melt together 8
parts of brass and 5 parts of zinc。
158。 CHINESE WHITE COPPER
Melt together 40。4 parts of copper； 31。6 parts of nickel； 25。4 of zinc；
and 2。6 of iron。
159。 MANHEIM GOLD
Melt together 3 parts copper； 1 of zinc； and a little tin。
160。 TOMBACK； OR RED BRASS
Melt together 8 parts of copper； and 1 part of zinc。
161。 IMITATION GOLD
Take of platina 8 parts； of silver 4 parts； copper 12 parts； melt all
together。
162。 IMITATION SILVER
Take of block tin 100 parts； metallic antimony 8 parts； bismuth 1 part；
and 4 parts of copper； melt all together。
163。 TRUE IMITATION OF GOLD
Dr。 Harmsteadt's imitation of gold； which is stated not only to resemble
gold in colour； but also in specific gravity and ductility； consists of 16
parts of platinum； 7 parts of copper； and 1 of zinc； put in a crucible；
covered with charcoal powder； and melted into a mass。
164。 TRUE IMITATION OF SILVER
Imitation of pure silver； so perfect in its resemblance that no chemist
living can tell it from pure virgin silver。 It was obtained from
