I860.] on the Art of Calico-Printing, 203 



would have occupied more than a week in printing ; whereas the 

 same piece can now be printed in one single operation, which takes 

 tliree minutes, and costs 6s. or Qs, So rapid is the progress of one 

 branch of manufacture in connexion with another,, that it has only 

 recently been possible to produce the rollers capable of performing 

 this operation, that is to say, cylinders of copper 43 inches in circum- 

 ferece, by 44 inches long. For light styles of printing, the time 

 required to print a piece of 36 yards is not more than one minute. 



Chemistry. — ^But the discovery which has exercised more influence 

 than any other on the progress of calico printing, is the application 

 of chlorine gas as a bleaching agent. Previously to the employment 

 of this gas, (chiefly as bleaching powder) the imperfect bleaching of 

 a piece of calico required six weeks ; and as it had to be exposed to 

 the action of the atmosphere, a large surface of land was required. 

 Further, at that time, bleachers had to use potashes imported from 

 Canada ; whereas, at . the present time, thanks to the progress of 

 chemical knowledge, not only is soda-ash manufactured in this 

 country ; but by the application of bleaching powder, calicos are much 

 better bleached in 24 hours than they were formerly by a six weeks* 

 exposure to the atmosphere ; and even when an extra cleaning and 

 whiteness is required, as for madder goods, only two days are 

 necessary. The aid of machinery renders possible the continuous 

 process ; that is to say, several hundred pieces of gray calico are sewn 

 together, end to end, and made to pass from one operation to another, 

 without any pause, until they are bleached. So rapid and economical 

 is this method, that the cost of bleaching a piece of calico, does 

 not exceed one or two pence. Chlorine, again, renders a great ser- 

 vice to the calico-printer, by enabling him, after his madder goods 

 have been produced and soaped, to obtain fine whites without the 

 necessity of exposing them for several days in the meadows to the 

 action of the atmosphere. In fact, the discovery of garancine and 

 alizarine, and their application to calico-printing, have facilitated the 

 production of madder styles, at very low cost, as the whites of such 

 goods require no soaping, and only a little bleaching or cleaning 

 powder. 



Cotton has this peculiarity, as distinguished from wool and silk, 

 that it will not fix any organic colour, excepting indigo, without the 

 interposition of a mordant, which is generally a metallic oxide or salt. 

 The two most important discoveries in connexion with this necessity of 

 calico-printing were ; first, that made in 1820, by Mr. George Wood, 

 of Bankbridge, who found out the means of preparing calicos with 

 peroxide of tin, which enabled printers to produce a large variety of 

 prints called steam goods ; and secondly, that of Walter Crum, Esq., 

 F.R.S., who in a paper presented to the British Association, at 

 Aberdeen, in 1859, showed that the tedious process of ageing madder 

 mordants''^ for three or four days, might] be dispensed with, by passing 

 the goods during a quarter of ^an hour through a moist atmosphere, at 

 a temperature of 80° to 100°, where the mordants absorb the required 



