Cartons lustrés (polished pasteboards for the cloth
manufacture) 18,992 francs
Cartons en feuilles (pasteboard in sheets) 6,352 --
Cartons moulés (papier-maché) 215,376 --
Cartons coupés et assemblés 54,184 --
Wrapping paper 178,544 --
White paper, and rayé (ruled) pour musique 2,903,075 --
Coloured paper in reams 58,541 --
Stained paper (paper hangings) in _rouleaux_, 1,885,387 --
Silk paper 3,240 --
---------
Total (= _£_208,000) 5,323,621 francs.
PARAFFINE. Distil beech-tar to dryness, rectify the heavy oil which
collects at the bottom of the receiver, and when a thick matter begins
to rise, set aside what is distilled, and urge the heat moderately as
long as any thing more distils. Pyrélaine passes over, containing
crystalline scales of paraffine. This mixture being digested with its
own volume of alcohol of 0·833, forms a limpid solution, which is to be
gradually diluted with more alcohol, till its bulk becomes 6 or 8 times
greater. The alcohol, which at first dissolves the whole, lets the
paraffine gradually fall. The precipitate being washed with cold
alcohol till it becomes nearly colourless, and then dissolved in boiling
alcohol, is deposited on cooling in minute spangles and needles of pure
paraffine.
Or the above mixture may be mixed with from 1/4 to 1/2 its weight of
concentrated sulphuric acid, and subjected for 12 hours to digestion, at
a heat of 150° F., till, on cooling, crystals of paraffine appear upon
the surface. These are to be washed with water, dissolved in hot
alcohol, and crystallized. Paraffine is a white substance, void of taste
and smell, feels soft between the fingers, has a specific gravity of
0·87, melts at 112° Fahr., boils at a higher temperature with the
exhalation of white fumes, is not decomposed by dry distillation, burns
with a clear white flame without smoke or residuum, does not stain
paper, and consists of 85·22 carbon, and 14·78 hydrogen; having the same
composition as olefiant gas. It is decomposed neither by chlorine,
strong acids, alkalis, nor potassium; and unites by fusion with sulphur,
phosphorus, wax, and rosin. It dissolves readily in warm fat oils, in
cold essential oils, in ether, but sparingly in boiling absolute
alcohol. Paraffine is a singular solid bicarburet of hydrogen; it has
not hitherto been applied to any use, but it would form admirable
candles.
PARCHMENT. (_Parchemin_, Fr.; _Pergament_, Germ.) This writing material
has been known since the earliest times, but is now made in a very
superior manner to what it was anciently, as we may judge by inspection
of the old vellum and parchment manuscripts. The art of making parchment
consists in certain manipulations necessary to prepare the skins of
animals of such thinness, flexibility, and firmness, as may be required
for the different uses to which this substance is applied. Though the
skins of all animals might be converted into writing materials, only
those of the sheep or the she-goat are used for parchment; those of
calves, kids, and dead-born lambs for vellum; those of the he-goat,
she-goat, and wolves for drum-heads; and those of the ass for
battledores. All these skins are prepared in the same way, with slight
variations, which need no particular detail.
They are first of all prepared by the leather-dresser. After they are
taken out of the lime-pit, shaved, and well washed, they must be set to
dry in such a way as to prevent their puckering, and to render them
easily worked. The small manufacturers make use of hoops for this
purpose, but the greater employ a _herse_, or stout wooden frame. This
is formed of two uprights and two cross-bars solidly joined together by
tenons and mortises, so as to form a strong piece of carpentry, which is
to be fixed up against a wall. These four bars are perforated all over
with a series of holes, of such dimensions as to receive slightly
tapered box-wood pins, truly turned, or even iron bolts. Each of these
pins is transpierced with a hole like the pin of a violin, by means of
which the strings employed in stretching the skin may be tightened.
Above the _herse_, a shelf is placed, for receiving the tools which the
workman needs to have always at hand. In order to stretch the skin upon
the frame, larger or smaller skewers are employed, according as a
greater or smaller piece of it is to be laid hold of. Six holes are made
in a straight line to receive the larger, and four to receive the
smaller skewers or pins. These small slits are made with a tool like a
carpenter’s chisel, and of the exact size to admit the skewer. The
string round the skewer is affixed to one of the bolts in the frame,
which are turned round by means of a key, like that by which pianos and
harps are tuned. The skewer is threaded through the skin in a state of
tension.
Every thing being thus prepared, and the skin being well softened, the
workman stretches it powerfully by means of the skewers; he attaches the
cords to the skewers, and fixes their ends to the iron pegs or pins. He
then stretches the skin, first with his hand applied to the pins, and
afterwards with the key. Great care must be taken that no wrinkles are
formed. The skin is usually stretched more in length than in breadth,
from the custom of the trade; though extension in breadth would be
preferable, in order to reduce the thickness of the part opposite the
backbone.
The workman now takes the fleshing tool represented under CURRYING. It
is a semi-circular double-edged knife, made fast into a double wooden
handle. Other forms of the fleshing-knife edge are also used. They are
sharpened by a steel. The workman seizes the tool in his two hands, so
as to place the edge perpendicularly to the skin, and pressing it
carefully from above downwards, removes the fleshy excrescences, and
lays them aside for making glue. He now turns round the _herse_ upon the
wall, in order to get access to the outside of the skin, and to scrape
it with the tool inverted, so as to run no risk of cutting the
epidermis. He thus removes any adhering filth, and squeezes out some
water. The skin must next be ground. For this purpose it is sprinkled
upon the fleshy side with sifted chalk or slaked lime, and then rubbed
in all directions with a piece of pumice-stone, 4 or 5 inches in area,
previously flattened upon a sandstone. The lime gets soon moist from the
water contained in the skin. The pumice-stone is then rubbed over the
other side of the skin, but without chalk or lime. This operation is
necessary only for the best parchment or vellum. The skin is now allowed
to dry, upon the frame; being carefully protected from sunshine, and
from frost. In the arid weather of summer a moist cloth needs to be
applied to it from time to time, to prevent its drying too suddenly;
immediately after which the skewers require to be tightened.
When it is perfectly dry, the white colour is to be removed by rubbing
it with the woolly side of a lambskin. But great care must be taken not
to fray the surface; a circumstance of which some manufacturers are so
much afraid, as not to use either chalk or lime in the polishing. Should
any grease be detected upon it, it must be removed by steeping it in a
lime-pit for 10 days, then stretching it anew upon the _herse_, after
which it is transferred to the _scraper_.
This workman employs here an edge tool of the same shape as the
fleshing-knife, but larger and sharper. He mounts the skin upon a frame
like the _herse_ above described; but he extends it merely with cords,
without skewers or pins, and supports it generally upon a piece of raw
calfskin, strongly stretched. The tail of the skin being placed towards
the bottom of the frame, the workman first pares off, with a sharp
knife, any considerable roughnesses, and then scrapes the outside
surface obliquely downwards with the proper tools, till it becomes
perfectly smooth: the fleshy side needs no such operation; and indeed
were both sides scraped, the skin would be apt to become too thin, the
only object of the scraper being to equalize its thickness. Whatever
irregularities remain, may be removed with a piece of the finest
pumice-stone, well flattened beforehand upon a fine sandstone. This
process is performed by laying the rough parchment upon an oblong plank
of wood, in the form of a stool; the plank being covered with a piece of
soft parchment stuffed with wool, to form an elastic cushion for the
grinding operation. It is merely the outside surface that requires to be
pumiced. The celebrated Strasburgh vellum is prepared with remarkably
fine pumice-stones.
If any small holes happen to be made in the parchment, they must be
neatly patched, by cutting their edges thin, and pasting on small pieces
with gum water.
The skins for drum-heads, sieves, and battledores are prepared in the
same way. For drums, the skins of asses, calves, or wolves are employed;
the last being preferred. Ass skins are used for battledores. For
sieves, the skins of calves, she-goats, and, best of all, he-goats, are
employed. Church books are covered with the dressed skins of pigs.
Parchment is coloured only green. The following is the process. In 500
parts of rain water, boil 8 of cream of tartar, and 30 of crystallized
verdigris; when this solution is cold, pour into it 4 parts of nitric
acid. Moisten the parchment with a brush, and then apply the above
liquid evenly over its surface. Lastly, the necessary lustre may be
given with white of eggs, or mucilage of gum arabic.
PARTING (_Départ_, Fr.; _Scheidung_, Germ.), is the process by which
gold is separated from silver. See ASSAY, GOLD, REFINING, and SILVER.
PASTEL, is the French name of coloured crayons.
PASTEL, is a dye-stuff, allied to INDIGO, which see.
PASTES, or FACTITIOUS GEMS. (_Pierres précieuses artificielles_, Fr.;
_Glaspasten_, Germ.) The general vitreous body called Strass, (from the
name of its German inventor,) preferred by Fontanier in his treatise on
this subject, and which he styles the Mayence base, is prepared in the
following manner:--8 ounces of pure rock-crystal or flint in powder,
mixed with 24 ounces of salt of tartar, are to be baked and left to
cool. The mixture is to be afterwards poured into a basin of hot water,
and treated with dilute nitric acid till it ceases to effervesce; and
then the frit is to be washed till the water comes off tasteless. This
is to be dried, and mixed with 12 ounces of fine white-lead, and the
mixture is to be levigated and elutriated with a little distilled water.
An ounce of calcined borax being added to about 12 ounces of the
preceding mixture in a dry state, the whole is to be rubbed together in
a porcelain mortar, melted in a clean crucible, and poured out into cold
water. This vitreous matter must be dried, and melted a second and a
third time, always in a new crucible, and after each melting poured into
cold water, as at first, taking care to separate the lead that may be
revived. To the third frit, ground to powder, 5 drachms of nitre are to
be added; and the mixture being melted for the last time, a mass of
crystal will be found in the crucible, of a beautiful lustre. The
diamond may be well imitated by this Mayence base. Another very fine
white crystal may be obtained, according to M. Fontanier, from 8 ounces
of white-lead, 2 ounces of powdered borax, 1/2 grain of manganese, and 3
ounces of rock crystal, treated as above.
The colours of artificial gems are obtained from metallic oxides. The
_oriental topaz_, is prepared by adding oxide of antimony to the base;
the amethyst, by manganese with a little of the purple of Cassius; the
beryl, by antimony and a very little cobalt; yellow artificial diamond
and opal, by horn-silver (chloride of silver); blue-stone or sapphire,
by cobalt. The following proportions have been given:--
For the _yellow diamond_. To 1 ounce of strass add 24 grains of chloride
of silver, or 10 grains of glass of antimony.
For the _sapphire_. To 24 ounces of strass, add 2 drachms and 26 grains
of the oxide of cobalt.
For the _oriental ruby_. To 16 ounces of strass, add a mixture of 2
drachms, and 48 grains of the precipitate of Cassius, the same quantity
of peroxide of iron prepared by nitric acid, the same quantity of golden
sulphuret of antimony and of manganese calcined with nitre, and 2 ounces
of rock crystal. Manganese alone, combined with the base in proper
quantity, is said to give a ruby colour.
For the _emerald_. To 15 ounces of strass, add 1 drachm of mountain blue
(carbonate of copper), and 6 grains of glass of antimony; or, to 1 ounce
of base, add 20 grains of glass of antimony, and 3 grains of oxide of
cobalt.
For the _common opal_. To 1 ounce of strass, add 10 grains of
horn-silver, 2 grains of calcined magnetic ore, and 26 grains of an
absorbent earth (probably chalk-marl) _Fontanier_.
M. Douault-Wiéland, in an experimental memoir on the preparation of
artificial coloured stones, has offered the following instructions, as
being more exact than what were published before.
The base of all artificial stones is a colourless glass, which he calls
_fondant_, or flux; and he unites it to metallic oxides, in order to
produce the imitations. If it be worked alone on the lapidary’s wheel,
it counterfeits brilliants and rose diamonds remarkably well.
This base or strass is composed of silex, potash, borax, oxide of lead,
and sometimes arsenic. The siliceous matter should be perfectly pure;
and if obtained from sand, it ought to be calcined, and washed, first
with dilute muriatic acid, and then with water. The crystal or flint
should be made redhot, quenched in water, and ground, as in the
potteries. The potash should be purified from the best pearlash; and the
borax should be refined by one or two crystallizations. The oxide of
lead should be absolutely free from tin, for the least portion of this
latter metal causes milkiness. Good red-lead is preferable to litharge.
The arsenic should also be pure. Hessian crucibles are preferable to
those of porcelain, for they are not so apt to crack and run out. Either
a pottery or porcelain kiln will answer, and the fusion should be
continued 24 hours; for the more tranquil and continuous it is, the
denser is the paste, and the greater its beauty. The following four
recipes have afforded good strass:--
Grains.
No. I.
Rock crystal 4056
Minium 6300
Pure potash 2154
Borax 276
Arsenic 12
No. II.
Sand 3600
Ceruse of Clichy (pure carbonate of lead) 8508
Potash 1260
Borax 360
Arsenic 12
No. III.
Rock crystal 3456
Minium 5328
Potash 1944
Borax 216
Arsenic 6
No. IV.
Rock crystal 3600
Ceruse of Clichy 8508
Potash 1260
Borax 360
_Topaz._ Grains.
Very white paste 1008
Glass of antimony 43
Cassius purple 1
Or,
Paste 3456
Oxide of iron, called saffron of Mars 36
_Ruby._
M. Wiéland succeeded in obtaining excellent imitations of rubies, by
making use of the topaz materials. It often happened that the mixture
for topazes gave only an opaque mass, translucent at the edges, and in
thin plates of a red colour. 1 part of this substance being mixed with 8
parts of strass, and fused for 30 hours, gave a fine yellowish
crystal-like paste, and fragments of this fused before the blowpipe,
afforded the finest imitation of rubies. The result was always the same.