CALICO-PRINTING 647 



No. 87. White Discharge for Blues. 1 gallon water, thicken with 2 Ibs. flour, 

 and 2 Ibs. dark British gum ; when partly cooled, add 2 Ibs. oxalic acid, and when 

 quite cold, 7i oz. measure sulphuric acid. A few seconds after the colour is printed 

 ou the padded cloth the blue is discharged, and a dirty white left in the printed 

 parts ; after printing, tho pieces are dried so as to leave them slightly clamp, and im- 

 mediately winced in chalk and water, then winced in sulphuric sours at 2 T., winced 

 and well washed ; the printed pattern is now a pure white, and if care has been 

 taken not to dry the bichromate too hard, and not expose it to sunlight, the blue is 

 bright and good. 



This ingenious process was the invention of Mr. John Mercer. At the moment the 

 block applies the preceding discharge to the bichromate dye, there is a sudden de- 

 coloration, and a production of a peculiar odour. 



The pieces padded with the bichromate must be dried at a moderate temperature, 

 and in the shade. Whenever watery solutions of chromate of potash and tartaric acid 

 arc mixed an effervescence takes place, during which the mixture possesses the power 

 of destroying vegetable colours. This property lasts no longer than the effervescence. 



In the ' Moniteur Scientifique ' of Dr. Qucsneville for July 1873 are described some 

 now processes, invented by P. Schiitzenberger and F. Lalande for the fixation of 

 indigo upon cloth. The active agent for the reduction of the indigo is the hydro- 

 sulphite of soda, discovered by the former, and which is made as follows : ' Bisulphite 

 of soda, standing at 30 to 35 Baum6, is brought in contact in a covered vessel with 

 twisted sheet zinc, or granulated zinc, filling up to the top of the vessel without 

 occupying more than one-fourth of its real volume. After the lapse of about one hour, the 

 liquid is poured into an excess of milk of lime, which precipitates the salts of zinc. 

 The clear liquid is drawn off either by filtration and pressure, or by decantation after 

 the addition of water. Air should be excluded as much as possible. By mixing the 

 hydro-sulphite thus obtained with ground indigo, and the amounts of lime or soda 

 necessary to dissolve the reduced indigo, we obtain at once a yellowish liquid con- 

 taining no insoluble matter except tho earthy impurities of the indigo.' One pound 

 of indigo may be thus reduced, so as to form a solution not exceeding 4 to 6 quarts in 

 volume. This solution is diluted with water to form a blue vat or an alkaline 

 solution of the reduced indigo, containing a large excess of hydro-sulphite of soda, is" 

 suitably thickened and printed by a copper roller in the ordinary printing-machine. 

 The oxidation during printing is so slight that after an hour's work, the remnant of 

 the colour is still yellow and soluble. The entire colour is utilised, 50 to 60 per cent, 

 less indigo being consumed with the new process than with the old. The shades 

 obtained are more beautiful and fast, and the impression is better defined. This new 

 indigo blue, requiring no subsequent fixing process, can be printed along with a great 

 number of other colours, such as aniline black, madder colours either for dyeing or 

 as extracts, catechu shades, Guignet's green and other colours fixed with albumen. 

 Specimens of some of these colours printed along with the new blue, are given in the 

 ' Moniteur,' and the new process would appear from these to be successful. 



Seventh Style: Discharge on Turkey-Red Ground. 



No. 88. White Discharge (Machine}. 8 Ibs. light British gum, 1 gallon tartaric-acid 

 liquor 62 T., 1 gallon acetic acid 6 T. 



No. 89. White Discharge (Block). The above colour a little thinner. 



No. 90. Black for Turkey Red. 7 gallons logwood liquor at 8 T., 1 gallon pyro- 

 ligneous acid, 10 Ibs. starch; boil and add 2 Ibs. 10 oz. copperas; boil again and 

 cool, then add 3 pints pernitrate of iron at 80 T., and 1 gallon of blue paste. 



No. 91. Blue Paste. (a) 6 Ibs. copperas, 2 quarts water; dissolve: (b) 4 Ibs. 

 prussiate of potash, 1 gallon of water ; dissolve. Mix a and b together, and add 

 1 quart standard red liquor No. 8, 1 quart nitric acid 60 T. 



No. 92. Yellow Discharge (Block). 1 gallon lime juice at 50 T., 4 Ibs. tartaric 

 acid, 4 Ibs. nitrate of leacl ; dissolve, thicken with 6 Ibs. pipe-clay, and 3 Ibs. gum- 

 Senegal. 



No. 93. Yellow Discharge (Machine"). Thicken tho above with 1 J Ib. starch, instead 

 of the pipe-clay and gum. 



No. 94. Yellow Discharge (Machine). 1 gallon lime juice at 40 T., 4 J Ibs. tartaric 

 acid, 5 Iba. white acetate of lead, 1 Ib. stareh ; boil and cool, then add 1 Ib. 14 oz. 

 nitric acid at 60 



No. 95. Blue Discharge (Machine). (a) 1 Ib. Prussian blue, 1 Ib. oxalic acid, 1 quart 

 hot water ; grind well together, and leave to react on each other 24 hours ; then (b) 

 3 quarts of water, l Ib. starch ; boil, and add 2 Ibs. tartaric acid, and mix a and b 

 together. 



No. 96. Green Discharge (Machine). 1 J gallon No. 95 blue, 1 gallon No. 94 yellow. 



