Preparation Of Balsam Of Sulphur.
—Take
16 parts oil of turpentine; 2 1/2 parts
spirits of turpentine; 8 parts flour of
sulphur.Place all in a chemical pot and heat
until it boils; continue the boiling until
no sulphur can be seen in it; now remove
from the heat and thin it with turpentine
until about the thickness of treacle, then
warm it again, stirring well; allow it to
cool until it reaches 45° F., then test it
with the hydrometer, and if specific
gravity is not 995 continue the addition of
turpentine and warming until correct,
let it thoroughly cool, then bottle, keeping
it air-tight.
To Purify Bismuth.
—Take 6 parts
bismuth metal, 3/4 part saltpeter. Melt
together in a biscuit cup, pour out on to
a slab, and take away all dirt, then grind
into a fine powder.
To Recover The Gold From The Remains Of The Foregoing Process.
—Put
all the “watery” solutions into a large
vessel and mix with a filtered saturated
solution of copperas; this will cause {381}
a precipitate of pure metallic gold to
gradually subside; wash it with cold
water and dry in an evaporating dish.All rags and settlings that are thick
should be burnt in a crucible until a
yellow mass is seen; then take this and
dissolve it in 2 parts muriatic acid and 1
part nitric acid. Let it remain in a porcelain
dish until it begins to thicken, and
crystals form on the sides. Add a little
nitric acid, and heat until crystals again
form. Now take this and mix with cold
water, add a solution of copperas to it
and allow it to settle; pour off the water,
and with fresh water wash till quite free
from acid. The gold may then be used
again, and if great care is exercised
almost one-half the original quantity
may be recovered.
The quantities given in the recipe
should produce about 13 to 15 parts of
the liquid gold. It does not in use require
any burnishing, and should be fired at rose-color
heat. If desired it can be fluxed
with Venice turpentine, oil of lavender,
or almonds.
Treatment Of Brittle Gold.
—I.—Add
to every 100 parts, by weight, 5 to 8 parts,
by weight, of cupric chloride and melt until
the oily layer which forms has disappeared.
Then pour out, and in most
cases a perfectly pliable gold will have
been obtained. If this should not be the
case after the first fusion, repeat the operation
with the same quantity of cupric
chloride. The cupric chloride must be
kept in a well-closed bottle, made tight
with paraffine, and in a dry place.II.—Pass chlorine gas through the
molten gold, by which treatment most of
the gold which has otherwise been set
aside as unfit for certain kinds of work
may be redeemed.
Assaying Of Gold.
—To determine the
presence of gold in ores, etc., mix a
small quantity of the finely powdered
ore in a flask with an equal volume of
tincture of iodine, shake repeatedly and
well, and leave in contact about 1 hour,
with repeated shaking. Next allow the
mixture to deposit and dip a narrow
strip of filtering paper into the solution.
Allow the paper to absorb, next to dry;
then dip it again into the solution, repeating
this 5 to 6 times, so that the
filtering paper is well saturated and impregnated.
The strip is now calcined,
as it were, and the ashes, if gold is
present, show a purple color. The
coloring disappears immediately if the
ashes are moistened with bromine water.
The same test may also be modified
as follows: Cover the finely pulverized
ore with bromine water, shake well and
repeatedly during about 1 hour of the
contact, and filter. Now add to the
solution stannic protochloride in solution,
whereby, in case gold is present, a purple
color (gold purple of Cassius) will at
once appear. In case the ore to be
assayed contains sulphides, it is well to
roast the ore previously, and should it
contain lime carbonate, it is advisable to
calcine the ore before in the presence of
ammonium carbonate.
Gold Welding.
—Gold may be welded
together with any metal, if the right
methods are employed, but best with
copper. Some recipes for welding agents
are here given.I.—Two parts by weight (16 ounces
equal 1 pound) of green vitriol; 1 part
by weight (16 ounces equal 1 pound) of
saltpeter; 6 parts by weight (16 ounces
equal 1 pound) of common salt; 1 part
by weight (16 ounces equal 1 pound) of
black manganic oxide or pulverized,
and mixed with 48 parts by weight (16
ounces equal 1 pound) of good welding
sand.
II.—Filings of the metal to be used in
welding are mixed with melted borax in
the usual proportion. To be applied in
the thickness desired.
III.—A mixture of 338 parts of
sodium phosphate and 124 parts of
boracic acid is used when the metal is
at dark-red heat. The metal is then to be
brought to a bright-red heat, and hammered
at the same time. The metal
easily softens at a high temperature, and
a wooden mallet is best. All substances
containing carbon should be removed
from the surface, as success depends upon
the formation of a fusible copper phosphate,
which dissolves a thin layer of
oxide on the surface, and keeps the latter
in good condition for welding.
To Recover Gold-leaf Waste.
—To recover
the gold from color waste, gold
brushes, rags, etc., they are burned up to
ashes. The ashes are leached with
boiling water containing hydrochloric
acid. The auriferous residuum is then
boiled with aqua regia (1 part nitric
acid and 3 parts hydrochloric acid),
whereby the gold is dissolved and gold
chloride results. After filtration and
evaporation to dryness the product is
dissolved in water and precipitated with
sulphate of protoxide of iron. The precipitated
gold powder is purified with
hydrochloric acid.
Gold From Acid Coloring Baths.
—I.—Different
lots are to be poured together {382}
and the gold in them recovered. The
following method is recommended:
Dissolve a handful of phosphate of iron
in boiling water, to which liquor add
the coloring baths, whereby small
particles of gold are precipitated. Then
draw off the water, being careful not to
dissolve the auriferous sediment at the
bottom. Free this from all traces of acid
by washing with plenty of boiling water;
it will require 3 or 4 separate washings,
with sufficient time between each to
allow the water to cool and the sediment
to settle before pouring off the water.
Then dry in an iron vessel by the fire and
fuse in a covered skittlepot with a flux.II.—The collected old coloring baths
are poured into a sufficiently large pot,
an optional quantity of nitro-muriatic
acid is added, and the pot is placed over
the fire, during which time the fluid is
stirred with a wooden stick. It is taken
from the fire after a while, diluted largely
with rain water and filtered through
coarse paper. The gold is recovered
from the filtered solution with a solution
of green vitriol which is stored in air-tight
bottles, then freshened with hot
water, and finally smelted with borax
and a little saltpeter.
Parting With Concentrated Sulphuric Acid.
—It is not necessary scrupulously to
observe the exact proportion of the gold
to the silver. After having prepared the
auriferous silver, place it in a quantity of
concentrated sulphuric acid contained in
a porcelain vessel, and let it come to a
violent boil. When the acid has either become
saturated and will dissolve no more,
or when solution is complete, remove
the dissolving vessel from the fire, let it cool,
and, for the purpose of clarifying, pour
dilute sulphuric acid into the solution.
The dissolved silver is next carefully
decanted from the gold sediment upon
the bottom, another portion of concentrated
acid is poured in, and the gold
is well boiled again, as it will still contain
traces of silver; this operation may be
repeated as often as is deemed necessary.
The solution, poured into the glass jars,
is well diluted with water, and the silver
is then precipitated by placing a sheet
of copper in the solution. The precipitate
is then freshened with hot water,
which may also be done by washing upon
the filter; the granulated silver (sulphate
of silver) is pressed out in linen, dried
and smelted. The freshened gold, after
drying, is first smelted with bisulphate of
soda, in order to convert the last traces
of silver into sulphate, and then smelted
with borax and a little saltpeter.
To Remove Gold From Silver.
—I.—Gold
is taken from the surface of silver
by spreading over it a paste, made of
powdered sal ammoniac with aqua fortis
and heating it till the matter smokes and
is nearly dry, when the gold may be
separated by rubbing it with the scratch
brush.II.—The alloy is to be melted and
poured from a height into a vessel of
cold water, to which a rotary motion is
imparted, or else it is to be poured
through a broom. By this means the
metal is reduced to a fine granular condition.
The metallic substance is then
treated with nitric acid, and gently
heated. Nitrate of silver is produced,
which can be reduced by any of the
ordinary methods; while metallic gold
remains as a black sediment, which must
be washed and melted.
Simple Specific Gravity Test.
—A certain
quantity of the metal is taken and
drawn out into a wire, which is to be
exactly of the same length as one from
fine silver; of course, both must have
been drawn through the same hole,
silver being nearly 1/2 lighter than gold,
it is natural that the one of fine silver
must be lighter, and the increased weight
of the wire under test corresponds to the
percentage of gold contained in it.
To Make Fat Oil Gold Size.
—First thin
up the fat oil with turpentine to workable
condition; then mix a little very finely
ground pigment with the gold size, about
as much as in a thin priming coat. Make
the size as nearly gold color as is convenient;
chrome yellow tinted with vermilion
is as good as anything for this purpose.
Then thin ready for the brush with
turpentine, and it will next be in order to
run the size through a very fine strainer.
Add japan, as experience or experiment
may teach, to make it dry tacky about
the time the leaf is to be laid. Dry slowly,
because the slower the size dries, the
longer it will hold its proper tackiness
when it is once in that condition.
To Dissolve Copper From Gold Articles.
—Take
2 ounces of proto-sulphate of
iron and dissolve it in 1/2 a pint of water,
then add to it in powder 2 ounces of
nitrate of potash; boil the mixture for
some time, and afterwards pour it into a
shallow vessel to cool and crystallize;
then to every part of the crystallized salt
add 8 ounces of muriatic acid, and
preserve in a bottle for use. Equal
parts of the above preparation and of
boiling water is a good proportion to use
in dissolving copper, or 1 part by weight {383}
of nitric acid may be used to 4 parts by
weight of boiling water as a substitute.Gold Purple.
I.—The solution of stannous chloride
necessary for the preparation of gold
purple is produced by dissolving pure tin
in pure hydrochloric acid (free from iron),
in such a manner that some of the tin remains
undissolved, and evaporating the
solution, into which a piece of tin is laid,
to crystallization.
II.—Recipe for Pale Purple.—Dissolve
2 parts by weight of tin in boiling
aqua regia, evaporate the solution at a
moderate heat until it becomes solid,
dissolve in distilled water and add 2
parts by weight of a solution of stannous
chloride (specific gravity 1.7) dilute with
9,856 parts by weight of water, stir into
the liquid a solution of gold chloride
prepared from 0.5 parts by weight of
gold and containing no excess of acid
(the latter being brought about by
evaporating the solution of gold chloride
to dryness and heating for some time to
about 320° F.). This liquid is dimmed
by the admixture of 50 parts by weight
of liquid ammonia which eliminates the
purple. The latter is quickly filtered off,
washed out and while still moist rubbed
up with the glass paste. This consists of
enamel of lead 20 parts by weight;
quartzose sand, 1 part by weight; red
lead, 2 parts by weight; and calcined
borax, 1 part by weight, with silver
carbonate, 3 parts by weight.
III.—Recipe for Dark Gold Purple.—Gold
solution of 0.5 parts by weight of
gold, solution of stannous chloride
(specific gravity 1.7) 7.5 parts by weight;
thin with 9,856 parts by weight of water,
separate the purple by a few drops of
sulphuric acid, wash out the purple and
mix same with enamel of lead 10 parts by
weight and silver carbonate, 0.5 parts
by weight.
IV.—Recipe for Pink Purple.—Gold
solution of 1 part by weight of gold;
solution of 50 parts by weight of alum in
19,712 parts by weight of water; add 1.5
parts by weight of stannous chloride solution
(specific gravity 1.7) and enough
ammonia until no more precipitate is
formed; mix the washed out precipitate,
while still moist, with 70 parts by weight
of enamel of lead and 2.5 parts by weight
of silver carbonate. According to the
composition of the purple various reds
are obtained in fusing it on; the latter
may still be brightened up by a suitable
increase of the flux.
To Render Pale Gold Darker.
—Take
verdigris, 50 parts by weight and very
strong vinegar, 100 parts by weight.
Dissolve the verdigris in the vinegar, rub
the pieces with it well, heat them and dip
them in liquid ammonia diluted with
water. Repeat the operation if the desired
shade does not appear the first time.
Rinse with clean water and dry.
To Color Gold.
—Gilt objects are improved
by boiling in the following solution:
Saltpeter, 2 parts by weight; cooking
salt, 1 part by weight; alum, 1 part
by weight; water, 24 parts by weight;
hydrochloric acid, 1 part by weight (1.12
specific gravity). In order to impart a
rich appearance to gilt articles, the following
paste is applied: Alum, 3 parts by
weight; saltpeter, 2 parts by weight;
zinc vitriol, 1 part by weight; cooking
salt, 1 part by weight; made into a paste
with water. Next, heat until black, on
a hot iron plate, wash with water, scratch
with vinegar and dry after washing.
Gold-leaf Striping.
—To secure a good
job of gilding depends largely for its
beauty upon the sizing. Take tube
chrome yellow ground in oil, thin with
wearing body varnish, and temper it
ready for use with turpentine. Apply
in the evening with an ox-tail striper, and
let it stand until the next morning, when,
under ordinary circumstances, it will be
ready for the gold leaf, etc. After the
gilding is done, let the job stand 24
hours before varnishing.
Composition Of Aqua Fortis For The Touch-stone.
—Following are the three
compositions mostly in use: I.—Nitric
acid, 30 parts; hydrochloric acid, 3 parts;
distilled water, 20 parts.II.—Nitric acid, 980 parts by weight;
hydrochloric acid, 20 parts by weight.
III.—Nitric acid, 123 parts by weight;
hydrochloric acid, 2 parts by weight.
To Remove Soft Solder From Gold.
—Place
the work in spirits of salts (hydrochloric
acid) or remove as much as possible
with the scraper, using a gentle
heat to remove the solder more easily.
Tipping Gold Pens.
—Gold pens are
usually tipped with iridium. This is
done by soldering very small pieces to
the points and filing to the proper shape.
To Recognize Whether An Article Is Gilt.
—Simply touch the object with a
glass rod previously dipped into a solution
of bichloride of copper. If the
article has been gilt the spot touched
should remain intact, while it presents a {384}
brown stain if no gold has been deposited
on its surface.
To Burnish Gilt Work.
—Ale has
proved a very good substitute for soap
and water in burnishing gilt as it increases
the ease and smoothness with
which it is accomplished. Vinegar is a
somewhat poorer substitute for ale.
White-gold Plates Without Solder.
—The
gold serving as a background for
white-gold is rolled in the desired
dimensions and then made perfectly
even under a powerful press. It is then
carefully treated with a file until a perfectly
smooth surface is obtained. After
a white-gold plate of the required thickness
has been produced in the same
manner, the surfaces of the two plates
to be united are coated with borax and
then pressed together by machine, which
causes the harder metal to be squeezed
slightly into the surface of the other,
furnishing a more solid and compact
mass. The metals, now partially united,
are firmly fastened together by means of
strong iron wire and a little more borax
solution is put on the edges. Then heat
to the temperature necessary for a complete
adhesion, but the heat must not be
so great as to cause an alloyage by fusing.
The whole is finally rolled out into the
required thickness.
To Fuse Gold Dust.
—Use such a
crucible as is generally used for melting
brass; heat very hot; then add the gold
dust mixed with powdered borax; after
some time a scum or slag will be on top,
which may be thickened by the addition
of a little lime or bone ash. If the dust
contains any of the more oxidizable
metals, add a little niter, and skim off
the slag or scum very carefully; when
melted, grasp the crucible with strong
iron tongs, and pour off immediately
into molds, slightly greased. The slag
and crucibles may be afterwards pulverized,
and the auriferous matter recovered
from the mass through cupellation by
means of lead.GOLD ALLOYS: See Alloys.
GOLD, EXTRACTION OF, BY AMALGAMATION: See Amalgams.
GOLD LETTERS ON GLASS, CEMENTS FOR AFFIXING:
See Adhesives, under Sign-Letter Cements.
GOLD, REDUCTION OF OLD PHOTOGRAPHIC: See Photography.
GOLD FOIL SUBSTITUTES AND GOLD LEAF: See Metal Foil.
GOLD-LEAF ALLOYS: See Alloys.
GOLD LEAF AND ITS APPLICATION: See Paints.
GOLD PLATING: See Plating.
GOLD, RECOVERY OF WASTE: See Jewelers’ Formulas.
GOLD RENOVATOR: See Cleaning Preparations and Methods.
GOLD, SEPARATION OF PLATINUM FROM: See Platinum.
GOLD SOLDERS: See Solders.
GOLD TESTING: See Jewelers’ Formulas.
GOLD VARNISH: See Varnishes.
GOLDWASSER: See Wines and Liquors.
GONG METAL: See Alloys.
GRAIN.
Formalin Treatment Of Seed Grain For Smut.
—Smut is a parasitic fungus,
and springs from a spore (which corresponds
to a seed in higher plants).
This germinates when the grain is
seeded and, penetrating the little grain
plant when but a few days old, grows up
within the grain stem. After entering
the stem there is no evidence of its
presence until the grain begins to head.
At this time the smut plant robs the
developing kernels of their nourishment
and ripens a mass of smut spores.These spores usually ripen before the
grain, and are blown about the field,
many spores becoming lodged on the
ripening grain kernels. The wholesale
agent of infection is the threshing
machine. For this reason the safest
plan is to treat all seed wheat and oats
each year.
Secure a 40 per cent solution of
formalin (the commercial name for
formaldehyde gas held in a water solution).
About 1 ounce is required for
every 5 bushels of grain to be treated. {385}
Clean off a space on the barn floor or
sweep a clean space on the hard level
ground and lay a good-sized canvas
down, on which to spread out the wheat.
See that the place where the grain is to
be treated is swept clean and thoroughly
sprinkled with the formalin solution
before placing the seed grain there.
Prepare the formalin solution immediately
before use, as it is volatile,
and if kept may disappear by evaporation.
Use 4 ounces of formalin for 10 gallons
of water. This is sufficient for 600
pounds of grain. Put the solution in a
barrel or tub, thoroughly mixing.
The solution can be applied with the
garden sprinkler. Care must be taken
to moisten the grain thoroughly. Sprinkle,
stir the grain up thoroughly and sprinkle
again, until every kernel is wet.
After sprinkling, place the grain in
a conical pile and cover with horse-blankets,
gunny sacks, etc. The smut
that does the damage lies just under the
glume of the oats or on the basal hairs
of the wheat. Covering the treated grain
holds the gas from the formalin within
the pile, where it comes in contact with
the kernels, killing such smut spores as
may have survived the previous treatment.
After the grain has remained in a
covered pile 2 to 4 hours, spread it out
again where the wind can blow over it,
to air and dry.
As soon as the grain can be taken in
the hand without the kernels sticking
together, it can be sown in the field.
The grain may be treated in the forenoon
and seeded in the afternoon.
Since this treatment swells the kernels
it hastens germination and should be
done in the spring just before seeding
time.
While the copper sulphate or bluestone
treatment is valuable in killing
smut, the formalin treatment can be
given in less time, is applied so easily
and is so effectual that it is recommended
as a sure and ready means of killing
smut in wheat and oats.
GRAINING CRAYONS: See Crayons.
GRAINING COLORS: See Pigments.
GRAINING WITH PAINT: See Paint.
GRAINING, PALISANDER: See Palisander.
GRAPE JUICE, PRESERVATION OF: See Wines and Liquors.
GRAPHITE AS A LUBRICANT: See Lubricants.
GRAVEL WALKS.
For cleaning gravel walks any of the
following may be used: I.—Gas-tar
liquor.
II.—Rock salt (cattle salt).
III.—Hydrochloric acid.
IV.—Sulphuric acid.
V.—Fresh limewater. The gas-tar
liquor must be poured out a few times
in succession, and must not touch the
tree roots and borders of the paths. This
medium is cheap. Cattle salt must likewise
be thrown out repeatedly. The use
of hydrochloric and sulphuric acids is
somewhat expensive. Mix 60 parts of
water with 10 parts of unslaked lime and
1 part of sulphuric acid in a kettle, and
sprinkle the hot or cold mixture on the
walks by means of a watering pot. If
limewater is used alone it must be fresh—1
part of unslaked lime in 10 parts of
water.
GRAVERS:
To Prepare Gravers For Bright-cutting.
—Set
the gravers after the sharpening
on the oilstone on high-grade emery
(tripoli) paper. Next, hone them further
on the rouge leather, but without tearing
threads from it. In this manner the silver
and aluminum engravers grind their
gravers. A subsequent whetting of the
graver on the touchstone is not advisable,
since it is too easily injured thereby. A
graver prepared as described gives excellent
bright engraving and never fails.In all bright-cutting the graver must
be highly polished; but when bright-cutting
aluminum a lubricant like coal-oil
or vaseline is generally employed with
the polished tool; a mixture of vaseline
and benzine is also used for this purpose.
Another formula which may be recommended
for bright-cutting aluminum is
composed of the following ingredients:
Mix 4 parts of oil of turpentine and 1
part of rum with 1 ounce of stearine.
Immerse the graver in any of the mixtures
before making the bright-cut.
GREASES: See Lubricants.
GREASE ERADICATORS: See Cleaning Preparations and Methods. {386}
GREASE PAINTS: See Cosmetics.
GREEN, TO DISTINGUISH BLUE FROM, AT NIGHT: See Blue.
GREEN GILDING: See Plating.
GRENADES: See Fire Extinguishers.
GRINDING: See Tool Setting.
GRINDER DISK CEMENT, SUBSTITUTE FOR: See Adhesives.
GRINDSTONES:
To Mend Grindstones.
—The mending
of defective places in grindstones is best
done with a mass consisting of earth-wax
(so-called stone-pitch), 5 parts, by
weight; tar, 1 part; and powdered sandstone
or cement, 3 parts, which is heated
to the boiling point and well stirred together.
Before pouring in the mass the
places to be mended must be heated by
laying red-hot pieces of iron on them.
The substance is, in a tough state, poured
into the hollows of the stone, and the
pouring must be continued, when it commences
to solidify, until even with the
surface.
Treatment Of The Grindstone.
—The
stone should not be left with the lower
part in the water. This will render it
brittle at this spot, causing it to wear off
more quickly and thus lose its circularity.
It is best to moisten the stone
only when in use, drop by drop from a
vessel fixed above it and to keep it quite
dry otherwise. If the stone is no longer
round, it should be made so again by
turning by means of a piece of gas pipe or
careful trimming, otherwise it will commence
to jump, thus becoming useless.
It is important to clean all tools and
articles before grinding, carefully removing
all grease, fat, etc., as the pores
of the stone become clogged with these
impurities, which destroy its grain and
diminish its strength. Should one side
of the grindstone be lighter, this irregularity
can be equalized by affixing
pieces of lead, so as to obtain a uniform
motion of the stone. It is essential that
the stone should be firm on the axis and
not move to and fro in the bearings.
Grindstone Oil.
—Complaints are often
heard that grindstones are occasionally
harder on one side than the other, the
softer parts wearing away in hollows,
which render grinding difficult, and soon
make the stone useless. This defect can
be remedied completely by means of
boiled linseed oil. When the stone is
thoroughly dry, the soft side is turned
uppermost, and brushed over with boiled
oil, which sinks into the stone, until the
latter is saturated. The operation takes
about 3 to 4 hours in summer. As soon
as the oil has dried, the stone may be
damped, and used without any further
delay. Unlike other similar remedies,
this one does not prevent the stone from
biting properly in the oiled parts, and the
life of the stone is considerably lengthened,
since it does not have to be dressed
so often.GROUNDS FOR GRAINING COLORS: See Pigments.
GUMS:
(See also Adhesives, under Mucilages.)
Gums, Their Solubility In Alcohol.
—The
following table shows the great range
of solubility of the various gums, and of
various specimens of the same gum, in
60 per cent alcohol:
| Acajon |
6.94 to 42.92 |
| Aden |
0.60 to 26.90 |
| Egyptian |
46.34 |
| Yellow Amrad |
26.90 to 32.16 |
| White Amrad |
0.54 to 1.50 |
| Kordofan |
1.40 to 6.06 |
| Australian |
10.67 to 20.85 |
| Bombay |
22.06 to 46.14 |
| Cape |
1.67 to 1.88 |
| Embavi |
25.92 |
| Gedda |
1.24 to 1.30 |
| Ghatti |
31.60 to 70.32 |
| Gheziereh |
1.50 to 12.16 |
| Halebi |
3.70 to 22.60 |
| La Plata |
9.65 |
| Mogadore |
27.66 |
| East Indian |
3.24 to 74.84 |
| Persian |
1.74 to 17.34 |
| Senegal |
0.56 to 14.30 |
Substitute For Gum Arabic.
—Dissolve
250 parts of glue in 1,000 parts of boiling
water and heat this glue solution on the
water bath with a mixture of about 10
parts of barium peroxide of 75 per cent
BaO2 and 5 parts of sulphuric acid
(66°) mixed with 115 parts of water, for
about 24 hours. After the time has
elapsed, pour off from the barium sulphate,
whereby a little sulphurous acid
results owing to reduction of the sulphuric
acid, which has a bleaching action
and makes the glue somewhat paler.
If this solution is mixed, with stirring,
and dried upon glass plates in the drying-room,
a product which can hardly be {387}
distinguished from gum arabic is obtained.
An envelope sealed with this
mucilage cannot be opened by moistening
the envelope. The traces of free
acid which it contains prevent the invasion
of bacteria, hence all putrefaction.The adhesive power of the artificial
gum is so enormous that the use of cork
stoppers is quite excluded, since they
crumble off every time the bottle is
opened, so that finally a perfect wreath
around the inner neck of the bottle is
formed. Only metallic or porcelain
stoppers should be used.
GUM ARABIC, INCREASING ADHESION OF: See Adhesives, under Mucilages.
GUM BICHROMATE PROCESS: See Photography.
GUM DROPS: See Confectionery.
GUM-LAC: See Oil.
GUMS USED IN MAKING VARNISH: See Varnishes.
GUN BARRELS, TO BLUE: See Steel.
GUN BRONZE: See Alloys, under Phosphor Bronze.
GUN COTTON: See Explosives.
GUN LUBRICANTS: See Lubricants.
GUNPOWDER: See Explosives.
GUNPOWDER STAINS.
A stain produced by the embedding
of grains of gunpowder in the skin is
practically the same thing as a tattoo
mark. The charcoal of the gunpowder
remains unaffected by the fluids of the
tissues, and no way is known of bringing
it into solution there. The only
method of obliterating such marks is
to take away with them the skin in
which they are embedded. This has
been accomplished by the application
of an electric current, and by the use
of caustics. When the destruction of
the true skin has been accomplished,
it becomes a foreign body, and if the
destruction has extended to a sufficient
depth, the other foreign body, the coloring
matter which has been tattooed in,
may be expected to be cast off with it.
Recently pepsin and papain have been
proposed as applications to remove the
cuticle. A glycerole of either is tattooed
into the skin over the disfigured part;
and it is said that the operation has
proved successful.
It is scarcely necessary to say that
suppuration is likely to follow such treatment,
and that there is risk of scarring.
In view of this it becomes apparent that
any such operation should be undertaken
only by a surgeon skilled in
dermatological practice. An amateur
might not only cause the patient suffering
without success in removal, but add
another disfigurement to the tattooing.
Carbolic acid has been applied to
small portions of the affected area at a
time, with the result that the powder and
skin were removed simultaneously and,
according to the physician reporting the
case, with little discomfort to the patient.
Rubbing the affected part with
moistened ammonium chloride once or
twice a day has been reported as a slow
but sure cure.
GUTTA-PERCHA.
Gutta-percha Substitute.
—I.—A decoction
of birch bark is first prepared,
the external bark by preference, being
evaporated. The thick, black residue
hardens on exposure to the air, and is
said to possess the properties of gutta-percha
without developing any cracks.
It can be mixed with 50 per cent of India
rubber or gutta-percha. The compound
is said to be cheap, and a good
non-conductor of electricity. Whether
it possesses all the good qualities of
gutta-percha is not known.II.—A new method of making gutta-percha
consists of caoutchouc and a rosin
soap, the latter compounded of 100 parts
of rosin, 100 parts of Carnauba wax, and
40 parts of gas-tar, melted together and
passed through a sieve. They are
heated to about 355° to 340° F., and
slowly saponified by stirring with 75
parts of limewater of specific gravity
1.06. The product is next put into a
kneading machine along with an equal
quantity of caoutchouc cuttings, and
worked in this machine at a temperature
of 195° F. or over. When sufficiently
kneaded, the mass can be rolled
to render it more uniform.
GUTTER CEMENT: See Cement and Putty.
GYPSUM:
See also Plaster.
Method Of Hardening Gypsum And Rendering It Weather-proof.
—Gypsum
possesses only a moderate degree of
strength even after complete hardening, {388}
and pieces are very liable to be broken
off. Various methods have been tried,
with a view to removing this defect and
increasing the hardness of gypsum. Of
these methods, that of Wachsmuth, for
hardening articles made of gypsum and
rendering them weather-proof, deserves
special notice. All methods of hardening
articles made of gypsum have this in
common: the gypsum is first deprived of
its moisture, and then immersed in a
solution of certain salts, such as alum,
green vitriol, etc. Articles treated by
the methods hitherto in vogue certainly
acquire considerable hardness, but are
no more capable of resistance to the
effects of water than crude gypsum.
The object of Wachsmuth’s process is
not merely to harden the gypsum, but to
transform it on the surface into insoluble
combinations. The process is as follows:
The article is first put into the required
shape by mechanical means, and
then deprived of its moisture by heating
to 212° to 302° F. It is then plunged
into a heated solution of barium hydrate,
in which it is allowed to remain for a
longer or shorter time, according to its
strength. When this part of the process
is complete, the article is smoothed by
grinding, etc., and then placed in a solution
of about 10 per cent of oxalic acid
in water. In a few hours it is taken out,
dried, and polished. It then possesses
a hardness surpassing that of marble,
and is impervious to the action of water.
Nor does the polish sustain any injury
from contact with water, whereas gypsum
articles hardened by the usual methods
lose their polish after a few minutes’
immersion in water. Articles treated by
the method described have the natural
color of gypsum, but it is possible to
add a color to the gypsum during the
hardening process. This is done by
plunging the gypsum, after it has been
deprived of its moisture, and before the
treatment with the barium solution,
into a solution of a colored metallic
sulphate, such as iron, copper, or chrome
sulphate, or into a solution of some
coloring matter. Pigments soluble in
the barium or oxalic-acid solutions may
also be added to the latter.Gypsum may be hardened and
rendered insoluble by ammonium borate
as follows: Dissolve boric acid in hot
water and add sufficient ammonia water
to the solution that the borate at first
separated is redissolved. The gypsum
to be cast is stirred in with this liquid,
and the mass treated in the ordinary
way. Articles already cast are simply
washed with the liquid, which is quickly
absorbed. The articles withstand the
weather as well as though they were of
stone.
GYPSUM FLOWERS: See Flowers.
GYPSUM, PAINT FOR: See Paint.
HAIR FOR MOUNTING.
The microscopist or amateur, who
shaves himself, need never resort to the
trouble of embedding and cutting hairs
in the microtome in order to secure very
thin sections of the hair of the face. If
he will first shave himself closely “with
the hair,” as the barbers say (i. e., in the
direction of the natural growth of the
hair), and afterwards lightly “against
the hair” (in the opposite direction to
above), he will find in the “scrapings”
a multitude of exceedingly thin sections.
The technique is very simple. The lather
and “scrapings” are put into a saucer or
large watch-glass and carefully washed
with clean water. This breaks down
and dissolves the lather, leaving the hair
sections lying on the bottom of the glass.
The after-treatment is that usually employed
in mounting similar objects.
HAIR PREPARATIONS
Dandruff Cures.
The treatment of that condition of the
scalp which is productive of dandruff
properly falls to the physician, but unfortunately
the subject has not been much
studied. One cure is said to be a sulphur
lotion made by placing a little sublimed
sulphur in water, shaking well, then allowing
to settle, and washing the head
every morning with the clear liquid.
Sulphur is said to be insoluble in
water; yet a sulphur water made as
above indicated has long been in use as a
hair wash. A little glycerine improves
the preparation, preventing the hair
from becoming harsh by repeated washings.
The exfoliated particles of skin or
“scales” should be removed only when
entirely detached from the cuticle. They
result from an irritation which is increased
by forcible removal, and hence
endeavors to clean the hair from them
by combing or brushing it in such a way
as to scrape the scalp are liable to be
worse than useless. It follows that
gentle handling of the hair is important
when dandruff is present.
{389}
| I.— |
Chloral hydrate |
2 ounces |
| Resorcin |
1 ounce |
| Tannin |
1 ounce |
| Alcohol |
8 ounces |
| Glycerine |
4 ounces |
| Rose water to make |
4 pints |
| II.— |
White wax |
3 1/2 drachms |
| Liquid petrolatum |
2 1/2 ounces |
| Rose water |
1 ounce |
| Borax |
15 grains |
| Precipitated sulphur |
3 1/2 drachms |
Pine-Tar Dandruff Shampoo.—
| Pine tar |
4 parts |
| Linseed oil |
40 parts |
Heat these to 140° F.; make solution
of potassa, U. S. P., 10 parts, and water,
45 parts; add alcohol, 5 parts, and
gradually add to the heated oils, stirring
constantly. Continue the heat until
saponified thoroughly; and make up
with water to 128 parts. When almost
cool, add ol. lavender, ol. orange, and ol.
bergamot, of each 2 parts.
Hair-curling Liquids.
It is impossible to render straight hair
curly without the aid of the iron or paper
and other curlers. But it is possible, on
the other hand, to make artificial curls
more durable and proof against outside
influences, such as especially dampness
of the air. Below are trustworthy recipes:
|
I |
II |
| Water |
70 |
80 |
| Spirit of wine |
30 |
20 |
| Borax |
2 |
— |
| Tincture of benzoin |
— |
3 |
| Perfume |
ad. lib. |
ad. lib. |
Hair Dressings And Washes:
Dressings for the Hair.—
| I.— |
Oil of wintergreen. |
20 drops |
| Oil of almond, essential |
35 drops |
| Oil of rose, ethereal |
1 drop |
| Oil of violets |
30 drops |
| Tincture of cantharides |
50 drops |
| Almond oil |
2,000 drops |
Mix.
Hair Embrocation.—
| II.— |
Almond oil, sweet |
280 parts |
| Spirit of sal ammoniac |
280 parts |
| Spirit of rosemary |
840 parts |
| Honey water |
840 parts |
Mix. Rub the scalp with it every
morning by means of a sponge.
Hair Restorer.—
| III.— |
Tincture of cantharides |
7 parts |
| Gall tincture |
7 parts |
| Musk essence |
1 part |
| Carmine |
0.5 part |
| Rectified spirit of wine |
28 parts |
| Rose water |
140 parts |
To be used at night.
Rosemary Water.—