225. TO COLOUR YELLOW ON COTTON
Wet 6 lbs. of goods thoroughly; and to the same quantity of water add 9 oz. of sugar of lead; and to the same quantity of water in another vessel, add 6 oz. of bichromate of potash; dip the goods first into the solution of sugar of lead, and next into that of the potash, and then again into the first; wring out, dry, and afterwards rinse in cold water.
226. FOR STAINING GLASS—No. 1 FLUX
Minimum, or red lead, 3 parts; white sand, washed, 1 part. This mixture is melted, by which it is converted into a greenish-yellow glass.
227. No. 2 FLUX
Of No. 1, 8 parts; fused borax, in powder, 1 part. This mixture is melted.
228. No. 3 FLUX
Fused borax, 5 parts; calcined flint, 3 parts; pure minium, 1 part. This mixture is also melted. The above fluxes are used in procuring the different colours for staining glass.
229. INDIGO BLUE
Oxide of cobalt, 1 part; flux No. 3, 2 parts.
230. TURQUOISE BLUE
Oxide of cobalt, 1 part; oxide of zinc, 3 or 4 parts; flux No. 3, 6 parts; melt and pour out. If it is not sufficiently green, increase the zinc and flux.
231. AZURE BLUE
Oxide of cobalt, 1 part; oxide of zinc, 2 parts; flux No. 2, 8 parts; melt them together.
232. DEEP AZURE BLUE
Oxide of cobalt, 1 part; oxide of zinc, 2 parts; flux No. 2, 5 parts.
The beauty of this colour depends on the proportion of flux. As
little as possible is to be used; it must, however, be brilliant.
Sometimes less is used than the proportion indicated.
233. SKY BLUE
Oxide of cobalt, 1 part; oxide of zinc, 2 parts; flux No. 2, 12 parts; pound up, melt, and pour out.
234. EMERALD GREEN
Oxide of copper, 1 part; antimonic acid, 10 parts; flux No. 1, 30 parts; pulverize together, and melt.
235. BLUEISH GREEN
Green oxide of chromium, 1 part; oxide of cobalt, 2 parts; triturate, and melt at a high heat. The product is a button slightly melted, from which is removed the portion in contact with the crucible. This button is pounded up, and three parts of flux No. 3, for one of the button, are added to it.
236. GRASS GREEN
Green oxide of chromium 1 part, flux No. 3, 3 parts, triturate and melt.
237. DEEP YELLOW
Antimonic acid 2 parts, subsulphate of iron 1 part, flux No. 1, 10 parts; melt and pour out. The subsulphate of iron may be increased a little, the proportions of flux vary.
238. JONQUILLE YELLOW FOR FLOWERS
Litharge 18 parts, sand 6 parts. The product of the calcination of equal parts of lead and tin 2 parts, carbonate of soda 1 part, antimonic acid 1 part, rub together, or triturate, and melt.
239. WAX YELLOW
Litharge 18 parts, sand 4 parts, oxide of antimony 2 parts, sienna earth 2 parts; melt. If it is too deep the proportion of sienna earth may be decreased.
240. ORANGE YELLOW
Chromate of lead 1 part, minium 3 parts.
241. BRICK RED
Yellow No. 240, 12 parts; red oxide of iron, 1 part.
242. DEEP BLOOD RED
Subsulphate of iron, calcined in a muffle until it becomes a beautiful capucine red, 1 part; flux No. 2, 3 parts; mix without melting.
243. BROWN YELLOW OCHRE
Yellow ochre No. 244, 10 parts; sienna earth, 1 part; triturate without melting.
244. DEEP YELLOW OCHRE—CALLED YELLOW BROWN
Subsulphate of iron, 1 part; oxide of zinc, 1 part; flux No. 2, 5 parts; triturate without melting.
245. PURE PURPLE
The purple powder of Cassius mixed while moist with flux No. 3, and sometimes a little chloride of silver previously melted with flux No. 3. If the purple, when prepared, does not melt sufficiently easy, some flux may be added when it is dry.
246. DEEP VIOLET
The purple of Cassius, in place of flux No. 3, flux No. 1 is mixed with it. Sometimes a little of blue No. 233 is added.
247. FLESH RED
The sulphate of iron, put in a small crucible, and lightly calcined, produces a suitable red oxide. Those which have the desired tone are selected. All the flesh reds are made in this way, and vary only in the degree of heat which they receive.
248. HAIR BROWN
Yellow ochre, No. 244, 15 parts; oxide of cobalt, 1 part; well triturated and calcined, in order to give the tone to it.
249. LIVER BROWN
Oxide of iron made of a red brown, and mixed with three times its weight of flux No. 2. A tenth of sienna earth is added to it if it is not sufficiently deep.
250. WHITE
The white enamel of commerce in cakes.
251. YELLOWISH GREY
Yellow No. 252, 1 part; blue No. 233, 1 part; oxide of zinc, 2 or 3 parts; flux No. 2, 5 parts; sometimes a little black is added, according to the tone which the mixture produces. The proportions of the blue and yellow vary.
252. YELLOW FOR BROWNS & GREENS
Antimonic acid, 2 parts; sulphate of iron 1 part; flux No. 1, 9 parts. This colour is melted and sometimes a little Naples Yellow is added if it is too soft, i.e., melts too easily.
253. BLUEISH GREY FOR MIXTURES
Blue previously made by melting together three parts of flux No. 1, and one part of the mixture of oxide of cobalt, 8 parts; oxide of zinc, 1 part; sulphate of iron calcined at a forge heat, 1 part; flux No. 2, 3 parts; triturate and add a little manganese in order to render it more grey.
254. GRAYISH BLACK FOR MIXTURES
Yellow ochre, No. 244, 15 parts; oxide of cobalt, 1 part; triturate and calcine in a crucible until it has the desired tone. A little oxide of manganese is added in order to make it blacker; sometimes a little more of oxide of cobalt.
255. DEEP BLACK
Oxide of cobalt, 2 parts; oxide of copper, 2 parts; oxide of manganese, 1 part; flux No. 1, 6 parts; fused borax, 1/2 part; melt and add oxide of manganese, 1 part; oxide of copper, 2 parts; triturate without melting.
256. GENERAL DIRECTIONS
The colours thus prepared after having been rubbed up on a plate of ground glass with the spirits of turpentine or lavender, thickened in the air are applied with a hair pencil. Before using them, however, it is necessary to try them on small pieces of glass, and expose them to the fire, to ascertain if the desired tone of colour is produced. The artist must be guided by these proof pieces in using his colours. The proper glass for receiving these colours should be uniform, colourless, and difficult of fusion. For this reason crown glass made with a little alkali or kelp is preferred. A design must be drawn upon paper and placed beneath the plate of glass. The upper side of the glass being sponged over with gum-water affords, when dry, a surface proper for receiving the colours, without the risk of their running irregularly, as they would be apt to do on the slippery glass. The artist draws on the plate, with a fine pencil all the traces which mark the great outlines and shades of the figures. This is usually done in black, and afterwards, when it is dry, the vitrifying colours are laid on by means of larger hair pencils. The yellow formed with chloride of silver is generally laid on the back of the glass, for it is apt to run with the other colours while heating.
The pigments used in painting on glass are principally matallic oxides and chlorides, and as, in most of these, the colour is not brought out until after the painting is submitted to heat, it is necessary to ascertain beforehand if the colours are properly mixed by painting on slips of glass, and exposing them to heat in a muffle. The painter is guided by these trial pieces in laying on his colours. To fire the paintings a furnace with a muffle is used. The muffles are made of refractory clay.
257. WHITE COATING FOR GOLD VARNISHES
A quart of strong parchment size and half a pint of water are to be made quite hot, and to these are to be added, (in small portions from time to time,) two good handsful of common whiting, passed through a fine sieve; this mixture is to be left to infuse for half an hour, when it is to be stirred carefully so that the amalgamation may be perfect. This coating is preferable to any glue or cement for coating picture frames, &c., on which is to be laid the tin or silver leaf, to be varnished with gold varnishes or lackers.