DYEING AND CALICO PRINTING. 315 



It should be observed that the great facility which attends the appli- 

 cation of the tar colours and pigments generally, as compared with mad- 

 der styles, reduces printing (apart from design) nearer to the level of a 

 mechanical art than would at first sight appear. In a word, thanks to 

 the brilliancy of those colours, their affinity for animal matters, and 

 the facility of using several pigments at the same time, the execution of 

 complicated designs on fabrics is no longer beset with what were for- 

 merly insuperable difficulties. 



A most interesting and valuable method of applying aniline colours 

 in fabrics has been devised by M. Onfroy, of Paris. It consists in print- 

 ing the aniline red, purple, or blue, on a solid black or brown ground, 

 in which gallic acid has been used instead of the ordinary tanning mat- 

 ters, the result of which is, that the black or brown ground is more 

 easily reduced, so that if he mixes with the aniline colours and animal 

 mordants some acid, such as oxalic acid, the black or brown is destroyed, 

 and the aniline colour fixed. This produces a new effect. While speak- 

 ing of this important improvement, it may be as well to allude to two 

 other inventions introduced by the same gentleman. One of these, 

 called by him Tireur mecaniqne, is a great improvement on the old Tobby 

 sieve, or the other mechanical means which have been devised to enable 

 the block-printer to carry on his block several colours at once. M. 

 Onfroy has succeeded in enabling the block -printer, by simply moving 

 his feet, to feed the surface of his sieve with a great variety of colours, 

 and to level them with a brush, also mechanically moved, so that whilst 

 he is applying the block to the fabric the machine is preparing the 

 colour for feeding it afresh. M. Onfroy has also invented a me- 

 chanical contrivance which may be very useful to the calico- 

 printer, and which he calls a riisiste tambour. It consists of a 

 large cylinder, three or four feet in circumference, covered with folds of 

 cloth, which are made to adhere by a solution of caoutchouc ; over this 

 is placed a layer of felt, in which the blanks in the pattern to be printed 

 are cut out. The roller is so placed in the machine as to print the resists 

 recpiired. 



It is highly probable that the style of pigment printing will receive 

 a great impulse from the introduction of lakes generally ; and this opinion 

 is supported by the beautiful specimens of cotton printed with alumina 

 lakes, of the colouring principle of madder exhibited in the French de- 

 partment, as well as by the varied collection of lakes, especially of bar- 

 wood lake, prepared with oxide of tin, hy Messrs. Roberts, Dale, and 

 Company. 



Steam Colours. — Though no marked improvement has occurred of 

 late years in this branch of calico printing, still it is so largely used at 

 the present day, especially in producing furniture prints, that it is desirable 

 to give an outline of its chief characteristics. Either the colour is mixed 

 with a mordant and then printed on the cloth and submitted to the action 



