of metallic oxides mixed and melted with it.
The oxide of cobalt produces blue; red is obtained by the Cassius
process. The purple of Cassius, which is one of the most brilliant of
colors, is used almost exclusively in enameling and miniature painting;
it is produced by adding to a solution of gold chloride a solution of
tin chloride mixed with ferric chloride until a green color appears.
The oxide of iron and of copper also produces red, but of a less rich
tone; chrome produces green, and manganese violet; black is produced by
the mixture of these oxides. Antimony and arsenic also enter into the
composition of enamels.
Enamels are of two classes—opaque and transparent. The opacity is
caused by the presence of tin.
When the mingled glass and oxides have been put in the crucible,
this is placed in the furnace, heated to a temperature of 1,832° or
2,200° F. When the mixture becomes fused, it is stirred with a metal
rod. Two or three hours are necessary for the operation. The enamel is
then poured into water, which divides it into grains, or formed into
cakes or masses, which are left to cool.
For applying enamels to metals, gold, silver, or copper, it is
necessary to reduce them to powder, which is effected in an agate
mortar with the aid of a pestle of the same material. During the
operation the enamel ought to be soaked in water.
For dissolving the impurities which may have been formed during the
work, a few drops of nitric acid are poured in immediately afterwards,
well mixed, and then got rid of by repeated washing with filtered
water. This should be carefully done, stirring the enamel powder with a
glass rod, in order to keep the particles in suspension.
The powder is allowed to repose at the bottom of the vessel, after
making sure by the taste of the water that it does not contain any
trace of acid; only then is the enamel ready for use.
For enameling a jewel or other object it is necessary, first to heat
it strongly, in order to burn off any fatty matter, and afterwards to
cleanse it in a solution of nitric acid diluted with boiling water.
After rinsing with pure water and wiping with a very clean cloth, it is
heated slightly and is then ready to receive the enamel.
Enamels are applied with a steel tool in the form of a spatula; water
is the vehicle. When the layers of enamel have been applied, the
contained water is removed by means of a fine linen rag, pressing
slightly on the parts that have received the enamel. The tissue absorbs
the water, and nothing remains on the object except the enamel powder.
It is placed before the fire to remove every trace of moisture. Thus
prepared and put on a fire-clap slab, it is ready for its passage to
the heat which fixes the enamel. This operation is conducted in a
furnace, with a current of air whose temperature is about 1,832° F. In
this operation the fire-chamber ought not to contain any gas.
Enamels are fused at a temperature of 1,292° to 1,472° F. Great
attention is needed, for experience alone is the guide, and the
duration of the process is quite short. On coming from the fire, the
molecules composing the enamel powder have been fused together and
present to the eye a vitreous surface covering the metal and adhering
to it perfectly. Under the action of the heat the metallic oxides
contained in the enamel have met the oxide of the metal and formed one
body with it, thus adhering completely.
«JEWELERS’ ENAMELS.»
Melt together:
Transparent Red.—Cassius gold purple, 65 parts, by weight; crystal
glass, 30 parts, by weight; borax, 4 parts, by weight.
Transparent Blue.—Crystal glass, 34 parts, by weight; borax, 6 parts,
by weight; cobalt oxide, 4 parts, by weight.
Dark Blue.—Crystal glass, 30 parts, by weight; borax, 6 parts, by
weight; cobalt oxide, 4 parts, by weight; bone black, 4 parts, by
weight; arsenic acid, 2 parts, by weight.
Transparent Green.—Crystal glass, 80 parts, by weight; cupric oxide, 4
parts, by weight; borax, 2 parts, by weight.
Dark Green.—Crystal glass, 30 parts, by weight; borax, 8 parts, by
weight; cupric oxide, 4 parts, by weight; bone black, 4 parts by
weight; arsenic acid, 2 parts, by weight.
Black.—Crystal glass, 30 parts, by weight; borax, 8 parts, by weight;
cupric oxide, 4 parts, by weight; ferric oxide, 3 parts, by weight;
cobalt oxide, 4 parts, by weight; manganic oxide, 4 parts, by weight.
White.—I.—Crystal glass, 30 parts, by weight; stannic oxide, 6 parts,
by weight; borax, 6 parts, by weight; arsenic acid, 2 parts, by weight.
II.—Crystal glass, 30 parts, by weight; sodium antimonate, 10 parts, by
weight. {309}
The finely pulverized colored enamel is applied with a brush and
lavender oil on the white enamel already fused in and then only heated
until it melts. For certain purposes, the color compositions may also
be fused in without a white ground. The glass used for white, No. 2,
must be free from lead, otherwise the enamel will be unsightly.
«Various Enamels for Precious Metals»: White.—Crystal glass, 30 parts,
by weight; oxide of tin, 6 parts, by weight; borax, 6 parts, by weight;
dioxide of arsenic, 2 parts, by weight, or silicious sand, 50 parts,
by weight; powder, consisting of 15 of tin per 100 of lead, 100 parts,
by weight; carbonate of potassium, 40 parts, by weight. Fuse the whole
with a quantity of manganese. To take away the accidental coloring,
pour it into water, and after having pulverized it, melt again 3 or 4
times.
Opaque Blue.—Crystal glass, 30 parts, by weight; borax, 6 parts, by
weight; cobalt oxide, 4 parts, by weight; calcined bone, 4 parts, by
weight; dioxide of arsenic, 2 parts, by weight.
Transparent Green.—Crystal glass, 30 parts, by weight; blue verditer, 4
parts, by weight; borax, 2 parts, by weight.
Opaque Green.—Crystal glass, 30 parts, by weight; borax, 8 parts, by
weight; blue verditer, 4 parts, by weight; calcined bone, 4 parts, by
weight; dioxide of arsenic, 2 parts, by weight.
Black.—I.—Crystal glass, 30 parts, by weight; borax, 8 parts, by
weight; oxide of copper, 4 parts, by weight; oxide of iron, 3 parts,
by weight; oxide of cobalt, 4 parts, by weight; oxide of manganese, 4
parts, by weight.
II.—Take 1/2 part, by weight, of silver; 2 1/2 parts of copper;
3 1/2 parts of lead, and 2 1/2 parts of muriate of ammonia. Melt
together and pour into a crucible with twice as much pulverized
sulphur; the crucible is then to be immediately covered that the
sulphur may not take fire, and the mixture is to be calcined over
a smelting fire until the superfluous sulphur is burned away. The
compound is then to be coarsely pounded, and, with a solution of
muriate of ammonia, to be formed into a paste which is to be placed
upon the article it is designed to enamel. The article must then be
held over a spirit lamp till the compound upon it melts and flows.
After this it may be smoothed and polished up in safety.
See also Varnishes and Ceramics for other enamel formulas.
ENAMEL COLORS, QUICK DRYING: See Varnishes.
ENAMEL REMOVERS: See Cleaning Preparations and Methods.
ENAMELING ALLOYS: See Alloys.
ENGINES (GASOLINE), ANTI-FREEZING SOLUTION FOR: See Freezing
Preventives.
«ENGRAVING SPOON HANDLES.»
After the first monogram has been engraved, rub it with a mixture of 3
parts of beeswax, 3 of tallow, 1 of Canada balsam, and 1 of olive oil.
Remove any superfluous quantity, then moisten a piece of paper with
the tongue, and press it evenly upon the engraving. Lay a dry piece
of paper over it, hold both firmly with thumb and forefinger of left
hand, and rub over the surface with a polishing tool of steel or bone.
The wet paper is thereby pressed into the engraving, and, with care, a
clear impression is made. Remove the paper carefully, place it in the
same position on another handle, and a clear impression will be left.
The same paper can be used 2 dozen times or more.
ENGRAVING ON STEEL: See Steel.
«Engravings: Their Preservation»
(See also Pictures, Prints, and Lithographs.)
«Cleaning of Copperplate Engravings.»—Wash the sheet on both sides
by means of a soft sponge or brush with water to which 40 parts of
ammonium carbonate has been added per 1,000 parts of water, and rinse
the paper each time with clear water. Next moisten with water in
which a little wine vinegar has been admixed, rinse the sheet again
with water containing a little chloride of lime, and dry in the air,
preferably in the sun. The paper will become perfectly clear without
the print being injured.
«Restoration of Old Prints.»—Old engravings, woodcuts, or printed
sheets that have turned yellow may be rendered white by first washing
carefully in water containing a little hyposulphite of soda, and
then dipping for a minute in javelle water. To prepare the latter,
put 4 pounds of bicarbonate of soda in a pan, pour over it 1 gallon
of boiling water; boil for 15 minutes, then stir in 1 {310} pound of
chloride of lime. When cold, pour off the clear liquid, and keep in a
jug ready for use.
Surprising results are obtained from the use of hydrogen peroxide in
the restoration of old copper or steel engravings or lithographs which
have become soiled or yellow, and this without the least injury to the
picture. The cellulose which makes the substance of the paper resists
the action of ozone, and the black carbon color of these prints is
indestructible.
To remove grease or other spots of dirt before bleaching, the
engravings are treated with benzine. This is done by laying each one
out flat in a shallow vessel and pouring the benzine over it. As
benzine evaporates very rapidly, the vessel must be kept well covered,
and since its vapors are also exceedingly inflammable, no fire or
smoking should be allowed in the room. The picture is left for several
hours, then lifted out and dried in the air, and finally brushed
several times with a soft brush. The dust which was kept upon the paper
by the grease now lies more loosely upon it and can easily be removed
by brushing.
In many cases the above treatment is sufficient to improve the
appearance of the picture. In the case of very old or badly soiled
engravings, it is followed by a second, consisting in the immersion of
the picture in a solution of sodium carbonate or a very dilute solution
of caustic soda, it being left as before for several hours. After the
liquid has been poured off, the picture must be repeatedly rinsed in
clear water, to remove any remnant of the soda.
By these means the paper is so far cleansed that only spots of mold or
other discolorations remain. These may be removed by hydrogen peroxide,
in a fairly strong solution. The commercial peroxide may be diluted
with 2 parts water.
The picture is laid in a shallow vessel, the peroxide poured over it,
and the vessel placed in a strong light. Very soon the discolorations
will pale.
«To Reduce Engravings.»—Plaster casts, as we know, can be perceptibly
reduced in size by treatment with water or alcohol, and if this is
properly done, the reduction is so even that the cast loses nothing
of its clear outline, but sometimes even gains in this respect by
contraction. If it is desired to reduce an engraved plate, make a
plaster cast of it, treat this with water or alcohol, and fill the
new cast with some easily fusible metal. This model, which will be
considerably smaller than the original, is to be made again in plaster,
and again treated, until the desired size is reached. In this way
anything of the kind, even medallions, can be reproduced on a smaller
scale.
ENLARGEMENTS: See Photography.
ENVELOPE GUM: See Adhesives, under Mucilages.
EPIZOOTY: See Veterinary Formulas.
«Essences and Extracts of Fruits»
«Preservation of Fruit Juices.»—The juices of pulpy fruits, when
fresh, contain an active principle known as pectin, which is the
coagulating substance that forms the basis of fruit jellies. This it
is which prevents the juice of berries and similar fruits from passing
through filtering media. Pectin may be precipitated by the addition of
alcohol, or by fermentation. The latter is the best, as the addition
of alcohol to the fresh juices destroys their aroma and injures the
taste. The induction of a light fermentation is far the better method,
not only preserving, when carefully conducted, the taste and aroma of
the fruit, but yielding far more juice. The fruit is crushed and the
juice subsequently carefully but strongly pressed out. Sometimes the
crushed fruit is allowed to stand awhile, and to proceed to a light
fermentation before pressure is applied; but while a greater amount of
juice is thus obtained, the aroma and flavor of the product are very
sensibly injured by the procedure.
To the juice thus obtained, add from 1 to 2 per cent of sugar, and put
away in a cool place (where the temperature will not rise over 70° or
75° F.). Fermentation soon begins, and will proceed for a few days. As
soon as the development of carbonic acid gas ceases, the juice begins
to clear itself, from the surface downward, and in a short time all
solid matter will lie in a mass at the bottom, leaving the liquid
bright and clear. Draw off the latter with a siphon, very carefully,
so as not to disturb the sedimentary matter. Fermentation should be
induced in closed vessels only, as when conducted in open containers
a fungoid growth is apt to form on the surface, sometimes causing
putrefactive, and at others, an acetic, fermentation, in either event
spoiling the juice for {311} subsequent use, except as a vinegar. The
vessels, to effect the end desired, should be filled only two-thirds
or three-fourths full, and then carefully closed with a tight-fitting
cork, through which is passed a tube of glass, bent at the upper end,
the short end of which passes below the surface of a vessel filled with
water. As soon as fermentation commences the carbonic acid developed
thereby escapes through the tube into the water, whence it passes off
into the atmosphere. When bubbles no longer pass off from the tube the
operation should be interrupted, and decantation or siphoning, with
subsequent filtration, commenced.
By proceeding in this manner all the aroma and flavor of the juices
are retained. If it is intended for preservation for any length of
time the juice should be heated on a water bath to about 176° F. and
poured, while hot, into bottles which have been asepticized by filling
with cold water, and placing in a vessel similarly filled, bringing
to a boiling temperature, and maintaining at this temperature until
the juice, while still hot, is poured into them. If now closed with
corks similarly asepticized, or by dipping into hot melted paraffine,
the juice may be kept unaltered for years. It is better, however, to
make the juice at once into syrup, using the best refined sugar, and
boiling in a copper kettle (iron or tin spoil the color), following the
usual precautions as to skimming, etc. The syrup should be poured hot
into the bottles previously heated as before described.
Ripe fruit may be kept in suitable quantities for a considerable time
if covered with a solution of saccharine and left undisturbed, this,
too, without deteriorating the taste, color, or aroma of the fruit if
packed with care.
Whole fruit may be stored in bulk, by carefully and without fracture
filling into convenient-sized jars or bottles, and pouring thereon a
solution containing a quarter of an ounce of refined saccharine to the
gallon of water, so filling each vessel that the solution is within an
inch of the cork when pressed into position. The corks should first of
all be immersed in melted paraffine wax, then drained, and allowed to
cool. When fruit juices alone are required for storage purposes they
are prepared by subjecting the juicy fruits to considerable pressure,
by which process the juices are liberated.
The sound ripe fruits are crushed and packed into felt or flannel bags.
The fruit should be carefully selected, rotten or impaired portions
being carefully removed; this is important, or the whole stock would
be spoiled. Several methods are adopted for preserving and clarifying
fruit juices.
A common way in which they are kept from fermenting is by the use
of salicylic acid or other antiseptic substance, which destroys the
fermentative germ, or otherwise retards its action for a considerable
time. The use of this acid is seriously objected to by some as
injurious to the consumer. About 2 ounces of salicylic acid, previously
dissolved in alcohol, to 25 gallons of juice, or 40 grains to the
gallon, is generally considered the proper proportion.
Another method adopted is to fill the freshly prepared cold juice into
bottles until it reaches the necks, and on the top of this fruit juice
a little glycerine is placed.
Juices thus preserved will keep in an unchanged condition in any
season. Probably one of the best methods of preserving fruit juices is
to add 15 per cent of 95 per cent alcohol. On such an addition, albumen
and mucilaginous matter will be deposited. The juice may then be stored
in large bottles, jars, or barrels, if securely closed, and when clear,
so that further clarification is unnecessary, the juice should finally
be decanted or siphoned off.
A method applicable to most berries is as follows:
Take fresh, ripe berries, stem them, and rub through a No. 8 sieve,
rejecting all soft and green fruit. Add to each gallon of pulp thus
obtained 8 pounds of granulated sugar. Put on the fire and bring just
to a boil, stirring constantly. Just before removing from the fire, add
to each gallon 1 ounce of a saturated alcoholic solution of salicylic
acid, stirring well. Remove the scum, and, while still hot, put into
jars and hermetically seal. Put the jars in cold water, and raise them
to the boiling point, to prevent them from bursting by sudden expansion
on pouring hot fruit into them. Fill the jars entirely full, so as to
leave no air space when fruit cools and contracts.
«Prevention of Foaming and Partial Caramelization of Fruit
Juices.»—Fresh fruit juices carry a notable amount of free carbonic
acid, which must make its escape on heating the liquid. This will do
easily enough if the juice be heated in its natural state, but the
addition of the sugar so increases the density of the fluid that the
acid finds escape difficult, and often the result is foaming. As to the
burning or partial caramelization of {312} the syrup, that is easily
accounted for in the greater density of the syrup at the bottom of the
kettle—the lighter portion, or that still carrying imprisoned gases,
remaining on top until it is freed from them. Constant stirring can
prevent this only partially, since it cannot entirely overcome the
results of the natural forces in action. The consequence is more or
less caramelization. The remedy is very simple. Boil the juices first,
adding distilled water to make up for the loss by evaporation, and add
the sugar afterwards.
«ESSENCES AND EXTRACTS:»
«Almond Extracts.»—
I.—Oil of bitter almonds 90 minims
Alcohol, 94 per cent, quantity sufficient to make 8 ounces.
II.—Oil of bitter almonds 80 minims
Alcohol 7 ounces
Distilled water, quantity sufficient to make 8 ounces.
III.—Oil of bitter almonds, deprived of its hydrocyanic acid 1 ounce
Alcohol 15 ounces
In order to remove the hydrocyanic acid in oil of bitter almonds,
dissolve 2 parts of ferrous sulphate in 16 parts of distilled water;
in another vessel slake 1 part freshly burned quicklime in a similar
quantity of distilled water, and to this add the solution of iron
sulphate, after the same has cooled. In the mixture put 4 parts of
almond oil, and thoroughly agitate the liquids together. Repeat the
agitation at an interval of 5 minutes, then filter. Put the filtrate
into a glass retort and distil until all the oil has passed over.
Remove any water that may be with the distillate by decantation, or
otherwise.
«Apricot Extract.»—
Linalyl formate 90 minims
Glycerine 1 ounce
Amyl valerianate 4 drachms
Alcohol 11 ounces
Fluid extract orris 1 ounce
Water, quantity sufficient to make 1 pint.
«Apple Extract.»—
Glycerine 1 ounce
Amyl valerianate 4 drachms
Linalyl formate 45 minims
Fluid extract orris 1 ounce
Alcohol 11 ounces
Water, quantity sufficient to make 1 pint.
«Apple Syrup.»—I.—Peel and remove the cores of, say, 5 parts of apples
and cut them into little bits. Put in a suitable vessel and pour over
them a mixture of 5 parts each of common white wine and water, and let
macerate together for 5 days at from 125° to 135° F., the vessel being
closed during the time. Then strain the liquid through a linen cloth,
using gentle pressure on the solid matter, forcing as much as possible
of it through the cloth. Boil 30 parts of sugar and 20 parts of water
together, and when boiling add to the resulting syrup the apple juice;
let it boil up for a minute or so, and strain through flannel.
II.—Good ripe apples are cut into small pieces and pounded to a pulp
in a mortar of any metal with the exception of iron. To 1 part of this
pulp add 11 parts of water. Allow this to stand for 12 hours. Colate.
To 11 parts of the colature add 1 part of sugar. Boil for 5 minutes.
Skim carefully. Bottle slightly warm. A small quantity of tartaric acid
may be added to heighten the flavor.
«Banana Syrup.»—Cut the fruit in slices and place in a jar; sprinkle
with sugar and cover the jar, which is then enveloped in straw and
placed in cold water and the latter is heated to the boiling point. The
jar is then removed, allowed to cool, and the juice poured into bottles.
«Cinnamon Essence.»—
Oil of cinnamon 2 drachms
Cinnamon, powdered 4 ounces
Alcohol, deodorized 16 ounces
Distilled water 16 ounces
Dissolve the oil in the alcohol, and add the water, an ounce at a time,
with agitation after each addition. Moisten the cinnamon with a little
of the water, add, and agitate. Cork tightly, and put in a warm place,
to macerate, 2 weeks, giving the flask a vigorous agitation several
times a day. Finally, filter through paper, and keep in small vials,
tightly stoppered.
«Chocolate Extract.»—Probably the best form of chocolate extract is
made as follows:
Curaçao cocoa 400 parts
Vanilla, chopped fine 1 part
Alcohol of 55 per cent 2,000 parts
Mix and macerate together for 15 days, express and set aside. Pack the
residue in a percolator, and pour on boiling water (soft) and percolate
until 575 parts pass through. Put the percolate {313} in a flask, cork,
and let cool, then mix with the alcoholic extract. If it be desired to
make a syrup, before mixing the extract, add 1,000 parts of sugar to
the percolate, and with gentle heat dissolve the sugar. Mix the syrup
thus formed, after cooling, with the alcoholic extract.
«Coffee Extracts.»—In making coffee extract, care must be used to avoid
extracting the bitter properties of the coffee, as this is where most
manufacturers fail; in trying to get a strong extract they succeed only
in getting a bitter one.
I.—The coffee should be a mixture of Mocha, 3 parts; Old Government
Java, 5 parts; or, as some prefer, Mocha, 3 parts; Java, 3 parts; best
old Rio, 2 parts.
Coffee, freshly roasted and pulverized 100 parts
Boiling water 600 parts
Pack the coffee, moistened with boiling water, in a strainer, or
dipper, placed in a vessel standing in the water bath at boiling point,
and let 400 parts of the water, in active ebullition, pass slowly
through it. Draw off the liquid as quickly as possible (best into
a vessel previously heated by boiling water to nearly the boiling
point), add 200 parts of boiling water, and pass the whole again
through the strainer (the container remaining in the water bath).
Remove from the bath; add 540 parts of sugar, and dissolve by agitation
while still hot.