Mixture of quercitron and cochineal.—Pad in the aluminous mordant, and dye with 2 libs. of quercitron, and 4 ounces of cochineal, when a capuchin colour will be obtained. If we pad with the following mordant; viz. 1 gallon of acetate of alumina of 1·056 spec. grav., and 1 of iron liquor of 1·02 spec. grav., and dye with 1 pound of quercitron, and 1 ounce of cochineal, we shall obtain a shade like boot-tops, of extreme vivacity.
Two ounces of cochineal will print a long piece of calico with rich pink figures, having acetate of alumina for a mordant. As the ground is hardly tinged by the dye, it neither needs nor admits of much clearing.
I have already mentioned that goods are sometimes padded with solution of perchloride of tin before printing-on them the steam colours, whereby they acquire both permanence and vivacity. I have also stated that the salts of tin at a high temperature are apt to corrode the fibre of the stuff, and therefore must be used with discretion. This danger is greatly lessened by adding to the perchloride of tin a sufficient quantity of caustic potash lye to form a stannate of potash. The goods are padded through this substance, diluted with water, dried with a moderate heat, and then immersed in very dilute sulphuric acid, which saturates the potash, and precipitates the tin oxide within the pores of the cloth. Calico thus prepared affords brilliant and permanent colours by the steam process, above described.
Printing of silks or woollen stuffs, such as merinoes and mousselin de laine, as also of mixed stuffs of silk and wool, such as chalys.—All these prints are applied, not by the cylinder but the block, and are fixed by the application of steam in one of four ways; 1. By the lanthorn; 2. By the cask; 3. By the chest; or 4. By the chamber.
1. By the lanthorn.—In this mode of exposure to steam, the goods are stretched upon a frame; and therefore the apparatus may be described under two heads; the lanthorn and the frame. The former is made of copper, in the shape of a box A B C D E, [fig. 238.], open below, and with a sloping roof above, to facilitate the trickling down of the water condensed upon the walls. The sides B C D E are 41⁄2 feet high, 6 feet long, and 4 feet wide. The distance of the point A from the line E B is 2 feet. At F is a brass socket, which may be stopped with a cork; and there is a similar one at the other side. This kind of penthouse may be raised by means of a pully with cords fixed to the four angles of the roof E B; and it rests upon the table G H, a little larger than the area of the box, which stands upon the four feet I K. Round the borders of the table there is a triangular groove a b, for receiving the lower edges of the box, and it is stuffed steam-tight with lists of cloth. Through the centre of the table, the two-inch steam pipe M passes; it is surmounted with an hemispherical rose pierced with numerous holes for the equal distribution of the steam. Right above it, a disc N is placed upon four feet. The tube L communicates with a box P, which has a syphon Q to let off the condensed water. At the upper part of this box the tube L terminates which brings the steam. The little table G H slopes towards the part G, where the syphon R is placed for drawing off the water.
The frame has such dimensions, that it may stand in the four corners of the table at S S, as pointed out by the dotted lines. The second part embraces an open square frame, which is formed by spars of wood 2 inches square, mortised together; and is 3 feet 8 inches wide, 5 feet 8 inches long, and 4 feet 3 inches high; it is strengthened with cross bars. Upon the two sides of its breadth, two rows of round brass hooks are placed, about half an inch apart; they are soldered to a copper plate fixed to uprights by means of screws.
Before hanging up the goods, a piece of cloth 3 feet 8 inches long, and 4 feet wide, is placed upon the row of hooks; and 3 feet of it are left hanging out.
One foot within, the hooks pass through the cloth. A similar one is fitted to the other side. This cloth is intended to cover the goods hung upon the hooks; and it is kept straight by resting upon strings. The pieces are attached zig-zag from one hook to another. When the frame is filled, the bag is put within the cloths; it has the same rectangular shape as the frame. The pieces are in this way all encased in the cloth; a bit of it being also put beneath to prevent moisture affecting that part.