only sufficiently to be able to bend it, a bath in boiling water will
answer. In steam at 120° C. (248° F.), however, it becomes so soft that
it may be easily kneaded like dough, so that one may even imbed in it
metal, wood, or any similar material. If it be intended to soften it
to solubility, the celluloid must then be scraped fine and macerated
in 90 per cent alcohol, whereupon it takes on the character of cement
and may be used to join broken pieces of celluloid together. Solutions
of celluloid may be prepared: 1. With 5 parts, by weight, of celluloid
in 16 parts, by weight, each of amyl acetate, acetone, and sulphuric
ether. 2. With 10 parts, by weight, of celluloid in 30 parts, by
weight, each of sulphuric ether, acetone, amyl acetate, and 4 parts,
by weight, camphor. 3. With 5 parts, by weight, celluloid in 50 parts,
by weight, alcohol and 5 parts, by weight, camphor. 4. With 5 parts,
by weight, celluloid in 50 parts, by weight, amyl acetate. 5. With 5
parts, by weight, celluloid in 25 parts, by weight, amyl acetate and 25
parts, by weight, acetone. {161}
It is often desirable to soften celluloid so that it will not break
when hammered. Dipping it in water warmed to 40° C. (104° F.) will
suffice for this.
«Mending Celluloid.»—Celluloid dishes which show cracks are easily
repaired by brushing the surface repeatedly with alcohol, 3 parts, and
ether, 4 parts, until the mass turns soft and can be readily squeezed
together. The pressure must be maintained for about one day. By putting
only 1 part of ether in 3 parts of alcohol and adding a little shellac,
a cement for celluloid is obtained, which, applied warm, produces
quicker results. Another very useful gluing agent for celluloid
receptacles is concentrated acetic acid. The celluloid fragments dabbed
with it stick together almost instantaneously.
See also Adhesives for Methods of Mending Celluloid.
«Printing on Celluloid.»—Printing on celluloid may be done in the
usual way. Make ready the form so as to be perfectly level on the
impression—that is, uniform to impressional touch on the face. The
tympan should be hard. Bring up the form squarely, allowing for about
a 3- or 4-sheet cardboard to be withdrawn from the tympan when about
to proceed with printing on the celluloid; this is to allow for the
thickness of the sheet of celluloid. Use live but dry and well-seasoned
rollers. Special inks of different colors are made for this kind of
presswork; in black a good card-job quality will be found about right,
if a few drops of copal varnish are mixed with the ink before beginning
to print.
«Colored Celluloid.»—
Black: First dip into pure water, then into a solution of nitrate of
silver; let dry in the light.
Yellow: First immerse in a solution of nitrate of lead, then in a
concentrated solution of chromate of potash.
Brown: Dip into a solution of permanganate of potash made strongly
alkaline by the addition of soda.
Blue: Dip into a solution of indigo neutralized by the addition of soda.
Red: First dip into a diluted bath of nitric acid; then into an
ammoniacal solution of carmine.
Green: Dip into a solution of verdigris.
Aniline colors may also be employed but they are less permanent.
«Bleaching Celluloid.»—If the celluloid has become discolored
throughout, its whiteness can hardly be restored, but if merely
superficially discolored, wipe with a woolen rag wet with absolute
alcohol and ether mixed in equal proportions. This dissolves and
removes a minute superficial layer and lays bare a new surface. To
restore the polish rub briskly first with a woolen cloth and finish
with silk or fine chamois. A little jeweler’s rouge or putzpomade
greatly facilitates matters. Ink marks may be removed in the same
manner. Printer’s ink may be removed from celluloid by rubbing first
with oil of turpentine and afterwards with alcohol and ether.
«Process of Impregnating Fabrics with Celluloid.»—The fabric is first
saturated with a dilute celluloid solution of the consistency of olive
oil, which solution penetrates deeply into the tissue; dry quickly
in a heating chamber and saturate with a more concentrated celluloid
solution, about as viscous as molasses. If oil be added to the
celluloid solution, the quantity should be small in the first solution,
e. g., 1 to 2 per cent, in the following ones 5 to 8 per cent, while
the outer layer contains very little or no oil. A fabric impregnated in
this manner possesses a very flexible surface, because the outer layer
may be very thin, while the interior consists of many flexible fibers
surrounded by celluloid.
CELLULOID CEMENTS AND GLUES: See Adhesives.
CELLULOID LACQUER: See Lacquer.
CELLULOID PUTTY: See Cements.
«Cements»
(See also Putties.)
For Adhesive Cements intended for repairing broken articles, see
Adhesives.
«Putty for Celluloid.»—To fasten celluloid to wood, tin, etc., use a
compound of 2 parts shellac, 3 parts spirit of camphor, and 4 parts
strong alcohol.
«Plumbers’ Cement.»—A plumbers’ cement consists of 1 part black rosin,
melted, and 2 parts of brickdust, thoroughly powdered and dried.
«Cement for Steam and Water Pipes.»—A cement for pipe joints is made as
follows: Ten pounds fine yellow ocher; 4 pounds {162} ground litharge;
4 pounds whiting, and 1/2 pound of hemp, cut up fine. Mix together
thoroughly with linseed oil to about the consistency of putty.
«Gutter Cement.»—Stir sand and fine lime into boiled paint skins while
hot and thick. Use hot.
«Cement for Pipe Joints.»—A good cement for making tight joints in
pumps, pipes, etc., is made of a mixture of 15 parts of slaked lime, 30
parts of graphite, and 40 parts of barium sulphate. The ingredients are
powdered, well mixed together, and stirred up with 15 parts of boiled
oil. A stiffer preparation can be made by increasing the proportions
of graphite and barium sulphate to 30 and 40 parts respectively, and
omitting the lime. Another cement for the same purpose consists of 15
parts of chalk and 50 of graphite, ground, washed, mixed, and reground
to fine powder. To this mixture is added 20 parts of ground litharge,
and the whole mixed to a stiff paste with about 15 parts of boiled oil.
This last preparation possesses the advantage of remaining plastic for
a long time when stored in a cool place. Finally, a good and simple
mixture for tightening screw connections is made from powdered shellac
dissolved in 10 per cent ammonia. The mucinous mass is painted over the
screw threads, after the latter have been thoroughly cleaned, and the
fitting is screwed home. The ammonia soon volatilizes, leaving behind a
mass which hardens quickly, makes a tight joint, and is impervious to
hot and cold water.
«Protection for Cement Work.»—A coating of soluble glass will impart to
cement surfaces exposed to ammonia not only a protective covering, but
also increased solidness.
Cemented surfaces can be protected from the action of the weather by
repeated coats of a green vitriol solution consisting of 1 part of
green vitriol and 3 parts of water. Two coatings of 5 per cent soap
water are said to render the cement waterproof; after drying and
rubbing with a cloth or brush, this coating will become glossy like
oil paint. This application is especially recommended for sick rooms,
since the walls can be readily cleaned by washing with soapy water.
The coating is rendered more and more waterproof thereby. The green
vitriol solution is likewise commendable for application on old and new
plastering, since it produces thereon waterproof coatings. From old
plastering the loose particles have first to be removed by washing.
«Puncture Cement.»—A patented preparation for automatically repairing
punctures in bicycle tires consists of glycerine holding gelatinous
silica or aluminum hydrate in suspension. Three volumes of glycerine
are mixed with 1 volume of liquid water glass, and an acid is stirred
in. The resulting jelly is diluted with 3 additional volumes of
glycerine, and from 4 to 6 ounces of this fluid are placed in each
tire. In case of puncture, the internal pressure of the air forces the
fluid into the hole, which it closes.
«To Fix Iron in Stone.»—Of the quickly hardening cements, lead and
sulphur, the latter is popularly employed. It can be rendered still
more suitable for purposes of pouring by the admixture of Portland
cement, which is stirred into the molten sulphur in the ratio of 1 to
3 parts by weight. The strength of the latter is increased by this
addition, since the formation of so coarse a crystalline structure as
that of solidifying pure sulphur is disturbed by the powder added.
«White Portland Cement.»—Mix together feldspar, 40–100 parts, by
weight; kaolin, 100 parts; limestone, 700 parts; magnesite, 20–40
parts; and sodium chloride, 2.5–5 parts, all as pure as possible, and
heat to 1430° to 1500° C. (2606° to 2732° F.), until the whole has
become sintered together, and forms a nice, white cement-like mass.
«Cement for Closing Cracks in Stoves.»—Make a putty of reduced iron
(iron by hydrogen) and a solution of sodium or potassium silicate, and
force it into the crack. If the crack be a very narrow one, make the
iron and silicate into paste instead of putty. This material grows
firmer and harder the longer the mended article is used.
«Cement for Waterpipe.»—I.—Mix together 11 parts, by weight, Portland
cement; 4 parts, by weight, lead white; 1 part, by weight, litharge;
and make to a paste with boiled oil in which 3 per cent of its weight
of colophony has been dissolved.
II.—Mix 1 part, by weight, torn-up wadding; 1 part, by weight, of
quicklime, and 3 parts, by weight, of boiled oil. This cement must be
used as soon as made.
«Cement for Pallet Stones.»—Place small pieces of shellac around the
stone when in position and subject it to heat. Often the lac spreads
unevenly or swells up; and this, in addition to being unsightly, is apt
to displace the stone. This can be avoided as follows: The pallets are
{163} held in long sliding tongs. Take a piece of shellac, heat it and
roll it into a cylinder between the fingers; again heat the extremity
and draw it out into a fine thread. This thread will break off, leaving
a point at the end of the lac. Now heat the tongs at a little distance
from the pallets, testing the degree of heat by touching the tongs with
the shellac. When it melts easily, lightly touch the two sides of the
notch with it; a very thin layer can thus be spread over them, and the
pallet stone can then be placed in position and held until cold enough.
The tongs will not lose the heat suddenly, so that the stone can easily
be raised or lowered as required. The projecting particles of cement
can be removed by a brass wire filed to an angle and forming a scraper.
To cement a ruby pin, or the like, one may also use shellac dissolved
in spirit, applied in the consistency of syrup, and liquefied again by
means of a hot pincette, by seizing the stone with it.
«DENTAL CEMENTS:»
«Fairthorne’s Cement.»—Powdered glass, 5 parts; powdered borax, 4
parts; silicic acid, 8 parts; zinc oxide, 200 parts. Powder very
finely and mix; then tint with a small quantity of golden ocher or
manganese. The compound, mixed before use with concentrated syrupy
zinc-chloride solution, soon becomes as hard as marble and constitutes
a very durable tooth cement.
«Huebner’s Cement.»—Zinc oxide, 500.0 parts; powdered manganese, 1.5
parts; yellow ocher, powdered, 1.5–4.0 parts; powdered borax, 10.0
parts; powdered glass, 100.0 parts.
As a binding liquid it is well to use acid-free zinc chloride,
which can be prepared by dissolving pure zinc, free from iron, in
concentrated, pure, hydrochloric acid, in such a manner that zinc is
always in excess. When no more hydrogen is evolved the zinc in excess
is still left in the solution for some time. The latter is filtered and
boiled down to the consistency of syrup.
Commercial zinc oxide cannot be employed without previous treatment,
because it is too loose; the denser it is the better is it adapted for
dental cements, and the harder the latter will be. For this reason it
is well, in order to obtain a dense product, to stir the commercial
pure zinc oxide into a stiff paste with water to which 2 per cent of
nitric acid has been added; the paste is dried and heated for some time
at white heat in a Hessian crucible.
After cooling, the zinc oxide, thus obtained, is very finely powdered
and kept in hermetically sealed vessels, so that it cannot absorb
carbonic acid. The dental cement prepared with such zinc oxide turns
very hard and solidifies with the concentrated zinc-chloride solution
in a few minutes.
«Phosphate Cement.»—Concentrate pure phosphoric acid till semi-solid,
and mix aluminum phosphate with it by heating. For use, mix with zinc
oxide to the consistency of putty. The cement is said to set in 2
minutes.
«Zinc Amalgam, or Dentists’ Zinc.»—This consists of pure zinc filings
combined with twice their weight of mercury, a gentle heat being
employed to render the union more complete. It is best applied as soon
as made. Its color is gray, and it is said to be effective and durable.
«Sorel’s Cement.»—Mix zinc oxide with half its bulk of fine sand, add a
solution of zinc chloride of 1.260 specific gravity, and rub the whole
thoroughly together in a mortar. The mixture must be applied at once,
as it hardens very quickly.
«Metallic Cement.»—Pure tin, with a small proportion of cadmium and
sufficient mercury, forms the most lasting and, for all practical
purposes, the least objectionable amalgam. Melt 2 parts of tin with 1
of cadmium, run it into ingots, and reduce it to filings. Form these
into a fluid amalgam with mercury, and squeeze out the excess of the
latter through leather. Work up the solid residue in the hand, and
press it into the tooth. Or melt some beeswax in a pipkin, throw in
5 parts of cadmium, and when melted add 7 or 8 parts of tin in small
pieces. Pour the melted metals into an iron or wooden box, and shake
them until cold, so as to obtain the alloy in a powder. This is mixed
with 2 1/2 to 3 times its weight of mercury in the palm of the hand,
and used as above described.
CEMENT COLORS: See Stone.
CEMENT, MORDANT FOR: See Mordants.
CEMENT, PAINTS FOR: See Paint.
CEMENT, PROTECTION OF, AGAINST ACID: See Acid-Proofing. {164}
CHAIN OF FIRE: See Pyrotechnics.
CHAINS (WATCH), TO CLEAN: See Cleaning Preparations and Methods.
«CHALK FOR TAILORS.»
Knead together ordinary pipe clay, moistened with ultramarine blue for
blue, finely ground ocher for yellow, etc., until they are uniformly
mixed, roll out into thin sheets, cut and press into wooden or metallic
molds, well oiled to prevent sticking, and allow to dry slowly at
ordinary temperature or at a very gentle heat.
CHAPPED HANDS: See Cosmetics.
CHARTA SINAPIS: See Mustard Paper.
CHARTREUSE: See Wines and Liquors.
«Ceramics»
GROUND CERAMICS—LAYING OIL FOR: See Oil.
«Notes for Potters, Glass-, and Brick-makers.»—It is of the highest
importance in selecting oxides, minerals, etc., for manufacturing
different articles, for potters’ use, to secure pure goods, especially
in the purchase of the following: Lead, manganese, oxide of zinc,
borax, whiting, oxide of iron, and oxide of cobalt. The different
ingredients comprising any given color or glaze should be thoroughly
mixed before being calcined, otherwise the mass will be of a streaky
or variegated kind. Calcination requires care, especially in the
manufacture of enamel colors. Over-firing, particularly of colors or
enamels composed in part of lead, borax, antimony, or litharge, causes
a dullness of shade, or film, that reduces their value for decorative
purposes, where clearness and brilliancy are of the first importance.
To arrest the unsightly defect of “crazing,” the following have been
the most successful methods employed, in the order given:
I.—Flux made of 10 parts tincal; 4 parts oxide of zinc; 1 part soda.
II.—A calcination of 5 parts oxide of zinc; 1 part pearl ash.
III.—Addition of raw oxide of zinc, 6 pounds to each hundredweight of
glaze.
To glazed brick and tile makers, whose chief difficulty appears to
be the production of a slip to suit the contraction of their clay,
and adhere strongly to either a clay or a burnt brick or tile, the
following method may be recommended:
Mix together:
Ball clay 10 parts
Cornwall stone 10 parts
China clay 7 parts
Flint 6 1/2 parts
To be mixed and lawned one week before use.
«To Cut Pottery.»—Pottery or any soft or even hard stone substance
can be cut without chipping by a disk of soft iron, the edge of which
has been charged with emery, diamond, or other grinding powder, that
can be obtained at any tool agency. The cutting has to be done with a
liberal supply of water fed continually to the revolving disk and the
substance to be cut.
«BRICK AND TILEMAKERS’ GLAZED BRICKS:»
«White.»—When the brick or tile leaves the press, with a very soft
brush cover the part to be glazed with No. 1 Slip; afterwards dip the
face in the same mixture.
«No. 1 Slip.»—
Same clay as brick 9 parts
Flint 1 part
Ball clay 5 parts
China 4 parts
Allow the brick to remain slowly drying for 8 to 10 hours, then when
moist dip in the white body.
«White Body.»—
China clay 24 parts
Ball clay 8 parts
Feldspar 8 parts
Flint 4 parts
The brick should now be dried slowly but thoroughly, and when perfectly
dry dip the face in clean cold water, and immediately afterwards in
glaze.
«Hard Glaze.»—
Feldspar 18 parts
Cornwall stone 3 1/2 parts
Whiting 1 1/2 parts
Oxide of zinc 1 1/2 parts
Plaster of Paris 3/4 part
{165}
«Soft Glaze.»—
White lead 13 parts
Feldspar 20 parts
Oxide of zinc 3 parts
Plaster of Paris 1 part
Flint glass 13 parts
Cornwall stone 3 1/2 parts
Paris white 1 1/4 parts
Where clay is used that will stand a very high fire, the white lead and
glass may be left out. A wire brush should now be used to remove all
superfluous glaze, etc., from the sides and ends of the brick, which
is then ready for the kiln. In placing, set the bricks face to face,
about an inch space being left between the two glazed faces. All the
mixtures, after being mixed with water to the consistency of cream,
must be passed 2 or 3 times through a very fine lawn. The kiln must not
be opened till perfectly cold.
«Process for Colored Glazes.»—Use color, 1 part, to white body, 7
parts. Use color, 1 part, to glaze, 9 parts.
«Preparation of Colors.»—The specified ingredients should all be
obtained finely ground, and after being mixed in the proportions given
should, in a saggar or some clay vessel, be fired in the brick kiln and
afterwards ground for use. In firing the ingredients the highest heat
attainable is necessary.
«Turquoise.»—
Oxide of zinc 8 parts
Oxide of cobalt 1 1/4 parts
«Grass Green.»—
Oxide of chrome 6 parts
Flint 1 part
Oxide of copper 1/2 part
«Royal Blue.»—
Pure alumina 20 parts
Oxide of zinc 8 parts
Oxide of cobalt 4 parts
«Mazarine Blue.»—
Oxide of cobalt 10 parts
Paris white 9 parts
Sulphate barytes 1 part
«Red Brown.»—
Oxide of zinc 40 parts
Crocus of martis 6 parts
Oxide of chrome 6 parts
Red lead 5 parts
Boracic acid 5 parts
Red oxide of iron 1 part
«Orange.»—
Pure alumina 5 parts
Oxide of zinc 2 parts
Bichromate of potash 1 part
Iron scale 1/2 part
«Claret Brown.»—
Bichromate of potash 2 parts
Flint 2 parts
Oxide of zinc 1 part
Iron scale 1 part
«Blue Green.»—
Oxide of chrome 6 parts
Flint 2 parts
Oxide of cobalt 3/4 part
«Sky Blue.»—
Flint 9 parts
Oxide of zinc 13 parts
Cobalt 2 1/2 parts
Phosphate soda 1 part
«Chrome Green.»—
Oxide of chrome 3 parts
Oxide of copper 1 part
Carbonate of cobalt 1 part
Oxide of cobalt 2 parts
«Olive.»—
Oxide of chrome 3 parts
Oxide of zinc 2 parts
Flint 5 parts
Oxide of cobalt 1 part
«Blood Red.»—
Oxide of zinc 30 parts
Crocus martis 7 parts
Oxide of chrome 7 parts
Litharge 5 parts
Borax 5 parts
Red oxide of iron 2 parts
«Black.»—
Chromate of iron 24 parts
Oxide of nickel 2 parts
Oxide of tin 2 parts
Oxide of cobalt 5 parts
«Imperial Blue.»—
Oxide of cobalt 10 parts
Black color 1 1/2 parts
Paris white 7 1/2 parts
Flint 2 1/2 parts
Carbonate of soda 1 part
«Mahogany.»—
Chromate of iron 30 parts
Oxide of manganese 20 parts
Oxide of zinc 12 parts
Oxide of tin 4 parts
Crocus martis 2 parts
«Gordon Green.»—
Oxide of chrome 12 parts
Paris white 8 parts
Bichromate of potash 4 1/2 parts
Oxide of cobalt 3/4 part
«Violet.»—
Oxide of cobalt 2 1/2 parts
Oxide of manganese 4 parts
Oxide of zinc 8 parts
Cornwall stone 8 parts
{166}
«Lavender.»—
Calcined oxide of zinc 5 parts
Carbonate of cobalt 3/4 part
Oxide of nickel 1/4 part
Paris white 1 part
«Brown.»—
Manganese 4 parts
Oxide of chrome 2 parts
Oxide of zinc 4 parts
Sulphate barytes 2 parts
«Dove.»—
Oxide of nickel 7 parts
Oxide of cobalt 2 parts
Oxide of chrome 1 part
Oxide of flint 18 parts
Paris white 3 parts
«Yellow Green.»—
Flint 6 parts
Paris white 4 parts
Bichromate of potash 4 1/2 parts
Red lead 2 parts
Fluorspar 2 parts
Plaster of Paris 1 1/2 parts
Oxide of copper 1/2 part
«BODIES REQUIRING NO STAIN:»
«Ivory.»—
Cane marl 16 parts
Ball clay 12 parts
Feldspar 8 parts
China clay 6 parts
Flint 4 parts
«Cream.»—
Ball clay 22 parts
China clay 5 1/2 parts
Flint 5 parts
Feldspar 3 1/2 parts
Cane marl 12 parts
«Black.»—
Ball clay 120 parts
Ground ocher 120 parts
Ground manganese 35 parts
«Buff.»—
Ball clay 12 parts
China clay 10 parts
Feldspar 8 parts
Bull fire clay 16 parts
Yellow ocher 3 parts
«Drab.»—
Cane marl 30 parts
Ball clay 10 parts
Stone 7 parts
Feldspar 4 parts
«Brown.»—
Red marl 50 parts
China clay 7 parts
Ground manganese 6 parts
Feldspar 3 parts
In making mazarine blue glazed bricks use the white body and stain the
glaze only.
Mazarine blue 1 part
Glaze 7 parts
For royal blue use 1 part stain to 6 parts white body, and glaze
unstained.
«Blood-Red Stain.»—Numerous brick manufacturers possess beds of clay
from which good and sound bricks or tiles can be made, the only
drawback being that the clay does not burn a good color. In many cases
this arises from the fact that the clay contains more or less sulphur
or other impurity, which spoils the external appearance of the finished
article. The following stain will convert clay of any color into a
rich, deep red, mixed in proportions of stain, 1 part, to clay, 60
parts.
«Stain.»—
Crocus martis 20 parts
Yellow ocher 4 parts
Sulphate of iron 10 parts
Red oxide of iron 2 parts
A still cheaper method is to put a slip or external coating upon the
goods. The slip being quite opaque, effectively hides the natural color
of the brick or tile upon which it may be used.
The process is to mix:
Blood-red stain 1 part
Good red clay 6 parts
Add water until the mixture becomes about the consistency of cream,
then with a sponge force the liquid two or three times through a very
fine brass wire lawn, No. 80, and dip the goods in the liquid as soon
as they are pressed or molded.
«Blue Paviors.»—Blue paving bricks may be produced with almost any kind
of clay that will stand a fair amount of heat, by adopting the same
methods as in the former case of blood-red bricks, that is, the clay
may be stained throughout, or an outside coating may be applied.
«Stain for Blue Paviors.»—
Ground ironstone 20 parts
Chromate of iron 5 parts
Manganese 6 parts
Oxide of nickel 1 part
Use 1 part clay and 1 part stain for coating, and 50 or 60 parts clay
and 1 part stain for staining through.
Fire blue paviors very hard.
«Buff Terra-Cotta Slip.»—
Buff fire clay 16 parts
China clay 6 parts {167}
Yellow ocher 3 parts
Ball clay 10 parts
Flint 4 parts
Add water to the materials after mixing well, pass through the fine
lawn, and dip the goods when soft in the liquid.
«Transparent Glaze.»—
Ground flint glass 4 parts
Ground white lead 4 parts
Ground oxide of zinc 1/4 part
This glaze is suitable for bricks or tiles made of very good red clay,
the natural color of the clay showing through the glaze. The goods
must first be fired sufficiently hard to make them durable, afterwards
glazed, and fired again. The glaze being comparatively soft will fuse
at about half the heat required for the first burning. The glaze may
be stained, if desired, with any of the colors given in glazed-brick
recipes, in the following proportions: Stain, 1 part; glaze, 1 part.
«SPECIAL RECIPES FOR POTTERY AND BRICK AND TILE WORKS:»
«Vitrifiable Bodies.»—The following mixtures will flux only at a very
high heat. They require no glaze when a proper heat is attained, and
they are admirably adapted for stoneware glazes.
I.—Cornwall stone 20 parts
Feldspar 12 parts
China clay 3 parts
Whiting 2 parts
Plaster of Paris 1 1/2 parts
II.—Feldspar 30 parts
Flint 9 parts
Stone 8 parts
China clay 3 parts
III.—Feldspar 20 parts
Stone 5 parts
Oxide of zinc 3 parts
Whiting 2 parts
Plaster of Paris 1 part
Soda crystals, dissolved 1 part
«Special Glazes for Bricks or Pottery at One Burning.»—To run these
glazes intense heat is required.
I.—Cornwall stone 40 parts
Flint 7 parts
Paris white 4 parts
Ball clay 15 parts
Oxide of zinc 6 parts
White lead 15 parts
II.—Feldspar 20 parts
Cornwall stone 5 parts
Oxide of zinc 3 parts
Flint 3 parts
Lynn sand 1 1/2 parts
Sulphate barytes 1 1/2 parts
III.—Feldspar 25 parts
Cornwall stone 6 parts
Oxide of zinc 2 parts
China clay 2 parts