CALICO-PRINTING 



machines at the rate of 90 to 120 yards per minute, -with the attendance of one man 

 and two boys. By chloring in this manner the stained -whites are bleached -without 

 degrading the dyed colours as would be the case if the goods were winced in a solution 

 of the hypochlorite. 



There are several varieties of garancin, each adapted to particular styles. For 

 dark full black, chocolate, and red, with brown or drab, and where there is no purple, 

 a garancin termed 'chocolate garancin,' made from the commonest descriptions of 

 madder, answers very well, and this class of goods is usually dyed with chocolate 

 garancin, assisted by small quantities of sumac, quercitron bark, and peachwood, 

 which additions give full rich shades. Where there is purple, none of those adjuncts 

 can be used, and the garancin requires to bo made from a superior description of 

 madder. 



Within the last few years great improvements in the manufacture of purple garan- 

 cins have been made. Good purple garancin contains two colouring matters, alizarine 

 and pupurine, one or two coloured resins and pectic acid. Of the two colouring 

 matters, alizarine only dyes a pleasing purple, purpurine giving a, reddish and com- 

 paratively dull shade ; the pectic acid and resins are simply injurious, though they 

 can bo to a considerable extent masked by the addition of a little chalk to the bock 

 when dyeing. Mr. S. Pincoffs, experimenting on various ways of destroying the 

 injurious parts of purple garancin without injuring the alizarine, discovered that seal- 

 ing up the garancin in a strong tube with a little water, and exposing the tube to a 

 high temperature for a few hours, so that the contents would bo under a pressure of 

 two atmospheres, greatly improved the garancin. Further experiments in the same 

 direction by Dr. E. Schunck resulted in a joint patent taken out on Oct. 15, 1852, by 

 Pincoffs ?.nd Schunck for the preparation of a substance called by them ' Commercial 

 Alizarine.' The process consisted in first making garancin in the ordinary manner, 

 but washing very carefully, so that no acid Was left in the substance. The garancin 

 was then filtered and pressed and packed into a strong iron cylinder, furnished with a 

 false bottom perforated with holes, on which the pressed and broken-up cake of garan- 

 cin was placed ; near the bottom of the cylinder, and under the false bottom, was a 

 small tap, for allowing the escape of condensed water, and both at the top and bottom, 

 the vessel was provided with pipes for the admission of steam. The material having 

 been placed on the false bottom, the man-hole lid in the upper part was closed, and 

 high-pressure steam at about 30 Ibs. to the square inch admitted and allowed to 

 blow freely through the bottom tap for a few minutes. This was then closed, and the 

 eteam allowed to act on the material for about fourteen hours, the bottom tap being 

 occasionally opened to blow off the condensed water. The steam was then turned off, 

 and the contents of the cylinder removed, dried, and ground. 



In this process the pectic acid is destroyed, and a large portion of the resins either 

 destroyed or rendered insoluble in the solution of the alizarine when dyeing. It is a 

 disputed point whether the purpurine is destroyed or converted into alizarine. A French 

 chemist has asserted that he has changed purpurine into alizarine by heating it in a 

 tube with water under a pressure of 4 atmospheres, but this statement has been 

 negatived by other chemists. The garancin operated upon by Pincoffs and Schunck's 

 patent has lost a considerable portion of its dyeing power, although it now dyes very 

 pure shades, hence it would appear that the purpurine is really destroyed. Higgin fol- 

 lowed soon after, patenting a mode of preparing a superior purple garancin, by boiling 

 for several hours the ordinary purple garancin with water and small quantities of 

 alkalies or alkaline salts. In this process the purpurine is not destroyed, but the 

 rosins and pectic acid are removed in solution in the menstruum employed. This 

 garancin, though not dyeing purple of such extreme purity as commercial alizarine, 

 has the advantage over this latter of dyeing black and good reds with a very good 

 purple. Pernod, a French garancin maker, subsequently patented a method of boil- 

 ing purple garancin in water in a tall wooden vat by high-pressure steam. In this 

 process the pectic acid is changed into a soluble modification of it, and washed 

 out with water afterwards. This preparation, as made by the firm in which 

 Mr. Pernod is a partner, is of great purity and strength, and compares very well with 

 the commercial alizarine, both these preparations dyeing purples almost as pure as 

 the finest soaped madder purples. 



These improved garancins stain the white grounds very little, and produce con- 

 siderably faster work than the ordinary garancins ; the goods may even bo soaped to 

 a considerable extent. A garancin that will bear as severe soaping as madder, or a 

 method of so dyeing with garancin as to produce the same effect, is still a desideratum. 

 When this can be accomplished, thero will bo an end of dyeing with madder, which 

 will be considered a raw material, and be all manufactured into garancin. 



Owing to the introduction of artificial alizarine there has been already a sensible 

 falling off in the consumption of these fine purple garancins, and it appears probable 



