Part 30

«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

IV.—Cornwall stone 118 parts Feldspar 40 parts Paris white 28 parts Flint 4 parts

V.—Feldspar 16 parts China clay 4 parts Stone 4 parts Oxide of zinc 2 parts Plaster of Paris 1 part

VI.—Feldspar 10 parts Stone 5 parts Flint 2 parts Plaster 1⁠/⁠2 part

The following glaze is excellent for bricks in the biscuit and pottery, which require an easy firing:

«White.»—

White lead 20 parts Stone 9 parts Flint 9 parts Borax 4 parts Oxide of zinc 2 parts Feldspar 3 parts

These materials should be procured finely ground, and after being thoroughly mixed should be placed in a fire-clay crucible, and be fired for 5 or 6 hours, sharply, or until the material runs down into a liquid, then with a pair of iron tongs draw the crucible from the kiln and pour the liquid into a bucket of cold water, grind the flux to an extremely fine powder, and spread a coating upon the plate to be enameled, previously brushing a little gum thereon. The plate must then be fired until a sufficient heat is attained to run or fuse the powder.

«POTTERY BODIES AND GLAZES:»

«Ordinary.»—

I.—China clay 2 1⁠/⁠2 parts Stone 1 1⁠/⁠2 parts Bone 3 parts

II.—China clay 5 parts Stone 2 1⁠/⁠2 parts Bone 7 parts Barytes 3 parts

III.—Chain clay 5 parts Stone 3 parts Flint 1⁠/⁠4 part Barytes 8 parts

«Superior.»—

I.—China clay 35 parts Cornwall stone 23 parts Bone 40 parts Flint 2 parts {168}

II.—China clay 35 parts Cornwall stone 8 parts Bone 50 parts Flint 3 parts Blue clay 4 parts

III.—China clay 8 parts Cornwall stone 40 parts Bone 29 parts Flint 5 parts Blue clay 18 parts

IV.—China clay 32 parts Cornwall stone 23 parts Bone 34 parts Flint 6 parts Blue clay 5 parts

V.—China clay 7 parts Stone 40 parts Bone 28 parts Flint 5 parts Blue clay 20 parts

«Finest China Bodies.»—

I.—China clay 20 parts Bone 60 parts Feldspar 20 parts

II.—China clay 30 parts Bone 40 parts Feldspar 30 parts

III.—China clay 25 parts Stone 10 parts Bone 45 parts Feldspar 20 parts

IV.—China clay 30 parts Stone 15 parts Bone 35 parts Feldspar 20 parts

«Earthenware Bodies.»—

I.—Ball clay 13 parts China clay 9 1⁠/⁠2 parts Flint 5 1⁠/⁠2 parts Cornwall stone 4 parts

II.—Ball clay 12 1⁠/⁠2 parts China clay 8 parts Flint 5 1⁠/⁠2 parts Cornwall stone 2 1⁠/⁠2 parts One pint of cobalt stain to 1 ton of glaze.

III.—Ball clay 13 1⁠/⁠4 parts China clay 11 parts Flint 4 parts Cornwall stone 5 parts Feldspar 4 parts Stain as required.

IV.—Ball clay 18 1⁠/⁠2 parts China clay 13 1⁠/⁠2 parts Flint 8 1⁠/⁠2 parts Stone 4 parts Blue stain, 2 pints to ton.

V.—Ball clay 15 parts China clay 12 parts Flint 6 parts Stone 4 parts Feldspar 4 parts Blue stain, 2 pints to ton.

VI. (Parian).— Stone 11 parts Feldspar 10 parts China clay 8 parts

«COLORED BODIES:»

«Ivory Body.»—

Ball clay 22 parts China 5 1⁠/⁠2 parts Flint 5 parts Stone 3 1⁠/⁠2 parts

«Dark Drab Body.»—

Cane marl 30 parts Ball clay 10 parts Cornwall stone 7 parts Feldspar 4 parts

«Black Body.»—

Ball clay 120 parts Ocher 120 parts Manganese 35 parts Cobalt carbonate 2 parts

Grind the three last mentioned ingredients first.

«Caledonia Body.»—

Yellow clay 32 parts China clay 10 parts Flint 4 parts

«Brown Body.»—

Red clay 50 parts Common clay 7 1⁠/⁠2 parts Manganese 1 part Flint 1 part

«Jasper Body.»—

Cawk clay 10 parts Blue clay 10 parts Bone 5 parts Flint 2 parts Cobalt 1⁠/⁠4 part

«Stone Body.»—

Stone 48 parts Blue clay 25 parts China clay 24 parts Cobalt 10 parts

«Egyptian Black.»—

Blue clay 235 parts Calcined ocher 225 parts Manganese 45 parts China clay 15 parts

«Ironstone Body.»—

Stone 200 parts Cornwall clay 150 parts {169} Blue clay 200 parts Flint 100 parts Calx 1 part

«Cream Body.»—