620 CALICO-PRINTING 



First Style : Madders. 



Madder styles being the most important, demand the most detailed descriptions. 

 The colours used are of the class termed mordants, which, not colouring matters them- 

 Belves, act by combining with both cloth and colouring matter. They are generally 

 the acetates or pyrolignites of iron and alumina. 



Red Liquor is the technical name of the pyrolignito of alumina iised as mordant 

 for red, &c. See RED LIQUOR. 



Resist-red Liquor is a pyrolignite of alumina which contains little or no sulphates, 

 and has the property of not being decomposed by protochloride of tin to so great an 

 extent as the ordinary Ked Liquor. 



Iron Liquor is the pyrolignite of iron used as mordant for black, purple, &c. 

 It is made by steeping iron borings, turnings, or thin pieces of scrap iron in crude 

 pyroligneous acid (see ACETIC ACID, and PYHOLIGNEOUS ACID), occasionally allowing 

 access of air to the iron by drawing off the liquor and pouring it upon iron contained 

 in another vat, the two vats being thus alternately full of liquor, the iron becoming 

 oxidised by the air when uncovered is more easily dissolved. This iron liquor is not 

 a mere solution of acetate of iron ; such a salt would be of little use as a printer's 

 mordant, being decomposed and peroxidised by the air with too great rapidity. It 

 contains, in addition to the protoacetate of iron, the various substances found in the 

 crude pyroligneous acid, such as pyrocatechin, pyroxanthogen, empyreumatic oil, resin, 

 furfurol, creosote, &c., which substances have a strong affinity for oxygen, and tend to 

 prevent the acetate of iron passing into a peroxidised state. The preparation of these 

 liquors on a large scale forms a separate business. 



Fixing Liquor. For a long time it has been customary to add to black and purple 

 colours, or mordants, some substance which has a tendency to prevent the oxide of 

 iron from passing to the state of peroxide. The oxide of iron necessary to produce 

 the best results with madder is a mixture of protoxide and peroxide of iron, pro- 

 bably the black or magnetic oxide, though this point is not precisely determined. If 

 the oxide should pass to the red oxide state, inferior shades are produced ; and the 

 object of the printer introducing fixing liquor into his colour is to prevent this injurious 

 tendency. 



The earliest fixing liquor used was a solution of arsenious acid; and though other 

 fixers have from time to time been introduced, the preparations of arsenic still hold 

 their ground. A very good fixing liquor, that has been much used in France and 

 England, is made as follows : 



No. 1. Purple Fixing Liquor. 7 gallons water, 1J gallon acetic acid, 9lbs. sal- 

 ammoniac, 91bs. arsenious acid ; boil till the arsenic is dissolved, and let stand till 

 quite clear. 



In 1844, Mr. John Mercer patented an assistant mordant liquor for the same pur- 

 pose, which was made as follows : 



No. 2. To 100 Ibs. potato starch, add 37 gallons water, 123 gallons nitric acid, 

 specific gravity 1*3, and 4 oz. oxide of manganese. The chemical action which takes 

 place amongst these ingredients is allowed to proceed till the nitric acid is destroyed. 

 To the residuum thus produced are added 50 gallons of pyroligneous acid, and the com- 

 pound is the assistant mordant liquor in a fit state to add to the various mordants used 

 in printing and dyeing. The intention in making this liquor is to carry on the de- 

 composition of the nitric acid and starch as far as possible without forming oxalic 

 acid, and as little as possible of carbonic acid, which is greatly aided by the catalytic 

 action of the oxide of manganese, preventing the formation of oxalic acid. Appa- 

 rently there is formed by this process saccharic acid, or an acid in a low state of 

 oxidation, which is the active agent in preventing the poroxidisement of the iron 

 when added to purple mordants. This liquor has been largely used, and is still pre- 

 ferred by some printers. Of late, various fixing liquors have been made and sold by 

 manufacturing chemists, pyroligneous acid and arsenious acid, or arsenite of soda, 

 forming the staple of them ; some of these have chlorate of potash added, the object 

 "being the formation of arscniato of iron when the cloth is dried, whereby the acetic 

 acid is more speedily driven off; and since arsoniate of iron does not pass beyond a 

 certain degree of oxidisement in the air, the mordant is kept in a proper state for 

 dyeing good colours. The following is also a good purple fixing colour : 



No. 3. Purple Fixing Liquor. Boil together till dissolved 2 gallons water, 25 Ibs. 

 soda crystals, 22 Ibs. arsenious acid. When dissolved, add to 50 gallons wood acid, 

 previously heated to 120 F. ; let stand for a day or two till the tar of the acid is 

 settled, and add 3 quarts muriatic acid. 



The following madder colours are from some in practical use ; and though almost 

 every colour-maker has different receipts for his colours, they may be taken to re- 

 present the general principles on which these colours are composed. 



