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The crude tartar and the charcoal must not be used where lead enters into the composition of the glass, and the nitre may be spared, because the yellow tinge, given to the glass by the lead, on account of which the nitre is used, is no detriment in this case, but only adds to the proper color. This color may also be prepared by crude antimony, as well as the colcothar, but it is more difficult to be managed, and not superior in its effect.
Hard Glass Resembling the Topaz, No. 3.
Take of the composition for hard glass, No. 1 or 2, 10 lbs. and an equal quantity of the gold-colored hard glass. Powder and fuse them together.
As there is a great variety in the color of the topaz, some being a deeper yellow, and others slightly tinged, the proportions of the yellow glass to the white may be accordingly varied at pleasure, the one here given being for the deepest.
Paste Resembling the Topaz, No. 4.
This may be done in the same manner as the preceding, but the saltpetre may be omitted in the original composition of the glass, and for the resemblance of the very slightly colored topazes neither the gold-colored paste nor any other tinging matter need be added, that of the lead being sufficient, when not destroyed by the nitre.
Glass Resembling the Chrysolite, No. 5.
Take of the composition for hard glass, No. 1 or 2, 10 lbs.; of colcothar, 6 drs. Proceed as with the above.
Paste Resembling the Chrysolite, No. 6.
Take of the composition for paste, No. 3 or 4, prepared without saltpetre, 10 lbs.; and of colcothar, 5 drs. Proceed as with the rest.
Hard Glass Resembling the Emerald, No. 1.
Take of the composition for hard glass, No. 1 or 2, 9 lbs.; of oxide of copper, 3 oz.; and of precipitated oxide of iron, 2 drs.
Paste Resembling the Emerald. No. 2.
Take of the composition for paste, No. 1 or 2 and proceed as with the above, but if the saltpetre be omitted in the preparation of the paste, a less proportion of the iron will serve.
Hard Glass of a Deep and very Bright Purple Color. No. 1.
Take of the composition for hard glass, No. 1 or 2, 10 lbs.; of zaffre, 6 drs.; of purple of Cassius, 1 dr. Proceed as with the rest.
Hard Glass of a Deep Purple Color, No. 2.
Take of the composition for hard glass, No. 1 or 2, 10 lbs.; of manganese, 1 oz.; and of zaffre, 1/2 oz. Proceed as with the other.
Paste of a Deep Purple Color, No. 3.
Take of the composition for pastes, No. 3 or 4, 10 lbs., and treat them as the foregoing.
Hard Glass of the Color of the Amethyst. No. 4.
Take of the composition of hard glass, No. 1 or 2, 10 lbs.; of manganese, 1 1/2 oz.; and of zaffre, 1 dr. Proceed as with the rest.
Paste of the Color of the Amethyst, No. 5.
Take of the composition for paste, No. 1 or 2, 10 lbs., and treat it as the preceding.
Paste Resembling the Diamond.
Take of white sand 6 lbs.; of red-lead, 4 lbs.; of pearlash, purified as above directed, 3 lbs.; of nitre, 2 lbs.; or arsenic, 5 oz.; and of manganese, 1 scr. Proceed as with the others, but continue the fusion for a considerable time on account of the large proportion of arsenic.
If this composition be thoroughly vitrified, and kept free from bubbles, it will be very white, and have a very great lustre; but if, on examination, it appears to incline to yellow, another scruple or more of the manganese may be added. It may be rendered harder by diminishing the proportion of lead, and increasing that of the salts, or fusing it with a very strong fire, but the diminution of the proportion of lead will make it have less of the lustre of the diamond.
Hard Glass, Perfectly Black.
Take of the composition for hard glass, No. 1 or 2, 10 lbs.; of zaffre, 1 oz.; of manganese and of colcothar, strongly calcined, each, 7 drs. Proceed as with the rest.
Paste, Perfectly Black.
Take of the composition for paste, No. 1 or 2, prepared with the saltpetre, 10 lbs.; of zaffre, 1 oz.; of manganese, 6 drs.; and of colcothar, 5 drs. Proceed as with the others.
White Opaque Glass, No. 1.
Take of the composition for hard glass, No. 1 or 2, 10 lbs.; of horn, ivory, or bone, calcined perfectly white, 1 lb. Proceed as with the others.
Paste of an Opaque Whiteness, No. 2.
Take of the composition No. 8 or 4, 10 lbs.; and make the same addition as to the above.
Glass of an Opaque Whiteness Formed by Arsenic, No. 3.
Take of flint-glass 10 lbs., and of very white arsenic, 1 lb. Powder and mix them thoroughly, by grinding them together, and then fuse them with a moderate heat till they be well incorporated, but avoid liquefying them more than to make a perfect union.
This glass has been made in great quantities, and has not only been formed into a variety of different kinds of vessels, but, being very white and fusible with a moderate heat, has been much used, as a white ground, for enamel in dial-plates, and other pieces which have not occasion to go several times into the fire to be finished. It will not, however, bear repeated burnings, nor a strong heat continued for any length of time, when applied to this purpose, without becoming transparent, to which likewise the smoke of a coal fire will also greatly contribute; but it answers the end very well in many cases, though even in those, enamel of the same degree of whiteness would be preferable, as this is always brittle, and of less firm and tenacious texture.
Hard Glass, or Paste., Formed by Calx of Tin or Antimony, No. 4.
Take of any of the compositions for hard glass or pastes, 10 lbs.; of oxide of tin (commonly called putty), or of antimony, or tin calcined by means of nitre, 1 1/2 lbs.; mix them well by grinding them together, and then fuse them with a moderate heat.
The glass of this kind made with the composition for pastes, differs in nothing from white enamel, but in the proportion of the calx of tin and antimony.
Semi-transparent White Glass and Paste Resembling the Opal, No. 5.
Take of any of the compositions for hard glass or paste, 10 lbs.; of horn, bone, or ivory, calcined to a perfect whiteness, 1/2 lb. Proceed as with the rest.
This white hard glass is much the same with the German glass formerly brought here in porringers, cream pots, vinegar cruets, and other such pieces, of which we frequently meet with the remains.
Fine Red Glass Resembling the Ruby, No. 1.
Take of the hard glass, No. 1 or 2, 1 lb.; of the purple of Cassius, 3 drs. Powder the glass, and grind the calx of gold afterwards with it in a glass, flint, or agate mortar, and then fuse them together.
This may be made of a stronger or more diluted color, by varying the proportion of the gold, in adjusting which, proper regard should be had to the application of the glass when made; for where this glass is set in rings, bracelets, or other close work, where foils can be used, a great saving may be made with regard to the color of it, without much injury to the effect; but for ear-rings, or other purposes where the work is set transparent, a full strong color should be given, which may be effected by the proportions directed in the composition.
Paste Resembling the Ruby, No. 2.
Take of the paste No. 3 or 4, 1 lb., and of calx caffei, or precipitation of gold by tin, 2 drs. Proceed in the mixture as with the above.
This will be equally beautiful with the above, and defective only in softness; but as that greatly takes away the value for some purposes, such as is appropriated to them may be tinged in a cheaper manner by the following means.
A Cheaper Paste Resembling the Ruby, No. 3.
Take of the composition for paste No. 3 or 4, of glass of antimony, each 1/2 lb., and of purple of Cassius, 1 1/2 dr. Proceed as with the others.
This will be considerably cheaper and will have much the same effect, except that it recedes more from the crimson to the orange.
Hard Glass Resembling the Garnet, No. 4.
Take of the composition for hard glass, No. 1 or 2, 2 lbs.; of glass of antimony, 1 lb.; of manganese, and of purple of Cassius, each 1 dr.
This composition is very beautiful, but too expensive, on account of the gold, for the imitation of garnets for common purposes; on which account the following may be substituted.
Hard Glass Resembling the Garnet, No. 5.
Take of the composition, No. 1 or 2, 2 lbs.; of the glass of antimony, 2 lbs.; and of manganese, 2 dr.
If the color be found too dark and purple in either this or the preceding composition, the proportion of manganese must be diminished.
Paste of the Color of Garnet, No. 6.
Take of the composition for paste, No. 1 or 2, and proceed as with the above.
Hard Glass Resembling the Vinegar Garnet, No. 7,
Take of the composition, No. 1 or 2, 2 lbs.; of glass of antimony, 1 lb.; of colcothar, 1/2 oz. Mix the colcothar with the uncolored glass, and fuse them together till the mass be perfectly transparent, then add the glass of antimony, powdered, stirring the mixture with the end of a tobacco-pipe, and continue them in the heat till the whole be perfectly incorporated.
Paste Resembling the Vinegar Garnet, No. 8.
Take of the composition for paste, No. 3 or 4 and proceed as with the foregoing.
Fictitious or Counterfeit Lapis Lazuli.
Take of any of the preceding compositions for hard glass, or paste, 10 lbs.; of calcined bones, horn, or ivory, 3/4 lb.; of zaffre, 1 oz. Fuse the uncolored composition with the zaffre and manganese, till a very deep transparent blue glass be produced. The mass being cold, powder it, and mix it with the calcined matter, by grinding them together. After which fuse them with a moderate heat till they be thoroughly incorporated, and then form the melted mass into cakes, by pouring it on a clean bright plate of copper or iron.
Another. - If it be desired to have it veined with gold, it may he done by mixing the gold powder with an equal weight of calcined borax, and tempering them with oil of spike, by which mixture, the cakes being painted with such veins as are desired, they must be put into a furnace of a moderate heat, and the gold will be cemented to the glass as firmly as if the veins had been natural. Another. - If the counterfeit lapis lazuli be desired of a lighter hue, the quantity of zaffre and manganese must be diminished; or, if it be required to be more transparent, that of the calcined horn, bone, or ivory, should be lessened.
To make Glass Resembling Red Cornelian.
Take of the composition for hard glass, No. 1 or 2, 2 lbs.; of glass of antimony, 1 lb.; of colcothar, 2 oz.; and of manganese, 1 dr.
Fuse the glass of antimony and manganese with the other glass first together, and then powder them well, and mix them with the colcothar, by grinding them together, and afterwards fuse the mixture with a gentle heat, till they are incorporated, but the heat must not be continued longer than is absolutely required to form them into a vitreous mass.
If it be desired to have the composition more transparent, part of the colcothar must be omitted.
Paste Resembling the Red Cornelian.
Take of the composition for paste, No. 1 or 2, 2 lbs.; and proceed as with the above.
Hard Glass Resembling White Cornelian.
Take of the composition for hard glass, No. 1 or 2, 2 lbs.; of yellow ochre, well washed, 2 dr.; and of calcined bones, each 1 oz. Mix them well by grinding them together, and fuse them with a gentle heat till the several ingredients he well incorporated in a vitreous mass.
Paste Resembling White Cornelian.
Take of the composition for pastes, No. 1 or 2, 1 lb.; and proceed as with the foregoing.
Hard Glass or Paste Resembling the Turquoise Stone.
Take of the composition for blue glass or paste, No. 7 or 8 (being those resembling the eagle marine), 10 lbs.; of calcined bone, or ivory, 1/2 lb. Powder and mix them well, and then fuse them in a moderate heat till they are thoroughly incorporated.
If the color be not so deep as may be desired, a small proportion of smalt may be added.
Brown Venetian Glass with Gold Spangles.
Take of the composition for hard glass, No. 2, and the composition for paste, No. 1, each 5 lbs.; and of colcothar, 1 oz. Mix them well, and fuse them till the iron be perfectly vitrified, and have tinged the glass of a deep transparent yellow brown color. Powder this glass, and add to it 2 lbs. of powdered glass of antimony, and mix them well by grinding them together. Take part of this mixture and rub into it 80 or 100 leaves of Dutch metal; and when the particles of the leaf seem suffi-ciently divided, mix the powder containing it with the other part of the glass. Fuse the whole then with a moderate heat till the powder runs into a vitreous mass fit to be wrought into any of the figures or vessels into which it is usually formed; but avoid a perfect liquefaction, because that destroys, in a short time, the equal diffusion of the spangles, and vitrifies, at least, part of the matter of which they are composed, converting the whole into a kind of transparent olive-colored glass.
To Paint And Stain Glass And Porcelain.
To paint upon glass is an art which has generally appeared difficult, yet there is no representation more elegant than that of a mezzotinto painted in this manner, for it gives all the softness that can be desired in a picture, and is easy to work, as there are no outlines to draw, nor any shades to make.
The prints are those done in mezzotinto; for their shades being rubbed down on the glass, the several lines, which represent the shady part of any common print, are by this means blended together and appear as soft and united as in any drawing of Indian-ink.
Provide such mezzotintos as are wanted; cut off the margin, then get a piece of fine grown-glass the size of the print, and as flat and free from knots and scratches as possible; clean the glass, and lay some Venice turpentine, quite thin and smooth, on one side, with a brush of hog's hair. Lay the print flat in water, and let it remain on the surface till it sinks; it is then damp enough; take it carefully out, and dab it between some papers, that no water may be seen, yet so as to be damp.
Next lay the damp print with its face uppermost upon a flat table, then hold the glass over it, without touching the turpentine, till it is exactly even with the print; let it fall gently on it. Press the glass down carefully with the fingers in several parts, so that the turpentine may stick to the print; after which take it up, then holding the glass towards you, press the prints with the fingers, from the centre towards the edges, till no blisters remain. When this is done, wet the back of the paint with a sponge, till the paper will rub off with the fingers; then rub it gently, and the white paper will roll off, leaving the impression only upon the glass; then let it dry, and, with a camel's hair pencil, dipped in oil of turpentine, wet it all over, and it will be perfectly transparent, and fit for painting.
Improved Method.
The first thing to be done, in order to paint, or stain glass in the modern way, is to design, and even color the whole subject on paper. Then choose such pieces of glass as are clear, even, and smooth, and proper to receive the several parts. Proceed to distribute the design itself, or the paper it is drawn on, into pieces suitable to those on the glass, always taking care that the glasses may join in the contours of the figures, and the folds of the draperies; that the carnations and other finer parts may not be impaired by the lead with which the pieces are to be joined together. The distribution being made, mark all the glasses, as well as papers, that they may be known again; which done, apply every part of the design upon the glass intended for it; and copy or transfer the design upon this glass with the black color diluted in gumwater, by tracing and following all the lines and strokes that appear through the glass, with the point of a pencil.
When these strokes are well dried, which will be in about 2 days (the work being only in black and white), give it a slight wash over with urine, gum-arabic, and a little black, and repeat this several times, according as the shades are desired to be heightened, with this precaution, never to apply a new wash till the former is suffi-ciently dried. This done, the lights and risings are given by rubbing off the color in the respective places with a wooden point, or by the handle of the pencil.
The colors are used with gum-water, the same as in painting in miniature, taking care to apply them lightly, for fear of effacing the outlines of the design: or even, for the greater security, to apply them on the other side; especially yellow, which is very pernicious to the other colors, by blending therewith. And here too, as in pieces of black and white, particular regard must always be had not to lay color on color, till such time as the former is well dried.
When the painting of all the pieces is finished, they are carried to the furnace to anneal, or to bake the colors. Colors Proper to Paint with Upon Glass.
The several sorts of colors, ground in oil for this purpose, may be had at all the color shops, etc.
Whites. - Flake white, podium.
Blacks. - Lampblack, ivory-black.
Browns. - Spanish brown, umber, spruce ochre, Dutch pink, orpiment.
Blues. - Blue bice, Prussian blue.
Reds. - Rose-pink, vermilion, red-lead, Indian-red, lake cinnabar.
Yellows. - English pink, masticot, English ochre, Saunders blue, smalt.
Greens. - Verdigris, terra vert, verditer.
The ultramarine for blue, and the carmine for red, are rather to be bought in powders, as in that state they are less apt to dry; and as the least tint of these will give the picture a cast, mix up what is wanted for present use with a drop or two of nut-oil upon the pallet with the pallet knife.
Then lay a sheet of white paper on the table, and taking the picture in the left hand, with the turpentine side next you, hold it sloping (the bottom resting on the white paper), and all outlines and tints of the prints will be seen on the glass; and nothing remains but to lay on the colors proper for the different parts, as follows:
To Use the Colors.
As the lights and shades of the picture open, lay the lighter colors first on the lighter parts of the print, and the darker over the shaded parts; and having laid on the brighter colors, it is not material if the darker sorts are laid a little over them; for the first color will hide those laid on afterwards. For example:
Reds. - Lay on the first red-lead, and shade with lake or carmine.
Yellows. - The lightest yellow maybe laid on first, and shaded with Dutch pink.
Blues. - Blue bice, or ultramarine, used for the lights, may be shaded with indigo.
Greens. - Lay on verdigris first, then a mixture of that and Dutch pink. This green may be lightened by an addition of Dutch pink.
When any of these are too strong, they may be lightened, by mixing white with them upon the pallet, or darken them as much as required by mixing them with a deeper shade of the same color.
The colors must not be laid on too thick - but if troublesome, thin them before using them, with a little turpentine oil.
Take care to have a pencil for each color, and never use that which has been used for green, with any other color without first washing it well with turpentine-oil, as that color is apt to appear predominant when the colors are dry.
Wash all the pencils, after using, in turpentine oil. The glass, when painted, must stand 3 or 4 days free from dust before it is framed.
To Draw on Glass.
Grind lampblack with gum-water and some common salt. With a pen or hair-pencil, draw the design on the glass, and afterwards shade and paint it with any of the following compositions:
Color for Grounds on Glass.
Take iron-filings and Dutch yellow beads, equal parts. If a little red cast is wanted, add a little copper filings. With a steel muller grind these together on a thick and strong copper plate, or on porphyry. Then add a little gum Arabic, borax, common salt, and clear water. Mix these with a little fluid, and put the composition in a phial for use. When it is to be used there is nothing to do but, with a hair pencil, to lay it quite flat on the design drawn the day before; and having left this to dry also for another day, with the quill of a turkey the nib unsplit, heighten the lights in the same manner as with crayons on blue paper. Whenever there are more coats of the above composition put one upon another, the shade will naturally be stronger; and when this is finished, lay the colors for garments and complexions.
To Prepare Lake for Glass.
Grind the lake with water impregnated with gum and salt; then make use of it with the brush. The shading is operated by laying a double, treble, or more coats of the color, where it is wanted darker.
Blue Purple for the same.
Make a compound of lake and indigo, ground together with gum and salt water, and use it as directed in the preceding article.
Green.
Mix with a proportionable quantity of gamboge ground together as above.
Yellow.
Grind gamboge with salt water only.
White.
Heighten much the white parts with a pen.
To Transfer Engravings on Glass.
Metallic colors prepared and mixed with fat oil, are applied to the stamp on the engraved plate. Wipe with the hand in the manner of the printers of colored plates; take a proof on a sheet of silver paper, which is immediately transferred on the tablet of glass destined to be painted, being careful to turn the colored side against the glass; it adheres to it, and as soon as the copy is quite dry, take off the superfluous paper by washing it with a sponge; there will remain only the color transferred to the glass; it is fixed by passing the glass through the ovens. The bases of all the colors employed in painting on glass, are oxidized metallic substances.
In painting on glass, it is necessary that the matter should be very transparent.
To Prepare Metallic Oxides and Precipitates of Gold. A solution of gold in aqua-regia, which is evaporated to dryness, leaves gold, which is used for glass, enamel, and porcelain gilding; or by precipitating the solution with green vitriol dissolved in water, a similar powder is produced. This powder is mixed with some essential oil, as oil of spike and calcined borax, and the whole made to adhere to the surface of the glass by a solution of gum Arabic. It is then applied with a fine pencil, and burnt in under a muffle.
To Prepare Oxide of Cobalt.
When regulus of cobalt is exposed to a moderate fire in the open air, it calcines; and is reduced to a blackish powder. This oxide vitrifies with vitrifiable matters and forms beautiful blue glasses. Cobalt is, at present, the only substance known which has the property of furnishing a very fine blue that is not changed by the most intense heat.
To Prepare Zaffre.
Zaffre is the oxide of cobalt, for painting pottery ware and porcelain of a blue color. Break the cobalt with hammers into pieces about the size of a hen's egg; and the stony gangue, with such other foreign matters, separate as much as possible. Pound the chosen mineral in stamping-mills, and sift it through brass-wire sieves. Wash off the lighter parts by water, and afterwards put it into a large flatbottomed arched furnace resembing a baking-oven, where the flame of the wood reverberates upon the ore, which stir occasionally, and turn with longhandled iron hooks or rakes; and the process is to be continued till its fumes cease. The oven or furnace terminates by a long horizontal gallery, which serves for a chimney, in which the arsenic, naturally mixed with the ore, sublimes. If the ore contains a little bismuth, as this semi-metal is very fusible, collect it at the bottom of the furnace. The cobalt remains in the state of a dark gray oxide, and is called zaffre. This operation is continued four, or even nine hours, according to the quality of the ore. The roasted ore being taken out from the furnace, such parts as are concreted into lumps, pound and sift afresh. Zaffre, in commerce, is never pure, being mixed with two, or rather three parts of powdered flints. A proper quantity of the best sort of these, after being ignited in a furnace, are to be thrown into water, to render them friable and more easily reduced to powder; which, being sifted, is mixed with the zaffre, according to the before-mentioned dose; and the mixture is put into casks, after being moistened with water. This oxide, fused with 3 parts of sand and 1 of potassa, forms a blue glass which, when pounded, sifted and ground in mills (included in large casks), forms smalt.
The blue of zaffre is the most solid and fixed of all the colors employed in vitrification. It suffers no change from the most violent fire. It is successfully employed to give shades of blue to enamels, and to crystal-glass made in imitation of opaque and transparent precious stones; as the lapis lazuli, the turquoise, the sapphire, and others.
Purple of Cassius.
Dissolve some pure gold in nitro-muriatic acid; add either acid or metal, until saturation takes place. Now dissolve some pure tin in the same kind of acid; observe the same point of saturation as with the gold, and pour it into the solution of gold. A purple powder will be precipitated, which must be collected and washed in distilled water.
This beautiful purple color, as before mentioned, is extremely useful to enamellers and to glass-stainers.
When brought into fusion with a clear, transparent glass, it tinges it of a purple, red, or violet color. Hence the method of making false rubies and garnets.
To Paint Colored Drawings on Glass.
This art is exercised two ways. 1. Plates of stained glass are cut into the shape of figures and joined by leaden outlines. On these plates a shading is afterwards traced by the painter, which gives features to the face and folds to the drapery.
- Vitrifiable colors are attached to plates of white glass, which are afterwards placed in the oven, and thus converted into a transparent enamelling. The first sort is cheaper, but the shading wears off by the insensible corrosion of the atmosphere. The second sort defies every accident except fracture; but the color of the figures suffers in the oven. For small objects, the first sort, and for large objects, the second, as far as art is concerned, seems best adapted.
Flux for Staining Glass.
- When the colors used are not affected by lead, 100 parts powdered quartz, 125 red-lead, 50 of bismuth.
- When the flux is required free from lead, 100 parts quartz, 75 glass of borax, 12 1/2 saltpetre, 12 1/2 powdered statuary marble.
Colors for Staining Glass.
To 6 cwt. of flux or flint-glass are to be added as follows: White (soft), 24 lbs. white arsenic, 6 lbs. antimony. White (hard), 200 lbs. putty-powder.
Blue (transparent), 2 lbs oxide of cobalt.
Azure, 6 lbs. protoxide of copper.
Ruby, 4 oz. oxide of gold.
Amethyst, 20 lbs. oxide of manganese.
Common Orange, 12 lbs. iron ore, 4 lbs. oxide of manganese.
Emerald Green, 12 lbs. copper scales and 12 lbs. iron ore.
Gold Topaz (canary glass), 3 lbs. oxide of uranium.
The colors will vary with the degree of heat to which the glass is subjected. The whole glass may be colored, or the mixture of flux and oxide may be laid on the surface, and then vitrified.
