56 farmers' and mechanics' journal. 



attraction between acetic acid and alumina is so weak, that they 

 cannot be made to combine directly ; but they may be united, and 

 the mordant formed, by decomposition, which is done by mixing 

 sugar of lead, or the acetate, with alum, the acetic acid of the 

 former combining with the alumina of the latter to form the acetate 

 of alumina, while the lead is precipitated in union with the sul- 

 phuric acid of the alum ; the mordant is therefore left in solution, 

 so that, by filtration, it is obtained pure. The iron liquor is pro- 

 cured by putting iron filings into vinegar, or rather pyroligneous 

 acid, by which it is slowly dissolved. The solutions thus formed, 

 are made of the requisite consistence with starch, to which in gene- 

 ral a little Brazil wood is added, to give it color, that the traces 

 may be seen when applied to the cloth. The instrument by which 

 this is done, is a block of wood, on which the pattern is cut. In 

 some places, it is interlaid with the felt of hat, which takes up a 

 great deal of the mordant when necessary ; and for some of the 

 nicer patterns, copper is sometimes used, by which the impression 

 is more delicate. The block being covered with the mordant, is 

 applied to the cloth, and struck with a mallet, or forced down by 

 machinery, to cause it to leave on as much as possible, and by ap- 

 plying it repeatedly, the whole web is properly covered with it. 

 It is then dried in a stove room, to fix it, and after being washed to 

 remove the superiluous part, is put into the dye-vat, by which the 

 color is imparted to the whole of it ; but by boiling it in bran and 

 water, and exposing it on the ground, only those parts previously 

 covered with the mordant are colored, so that the pattern is dyed 

 on it. 



" By applying different mordants to the same piece of cloth, dif- 

 ferent colored patterns may be produced. Thus, if part of a piece 

 of calico be covered with the aluminous mordant, another with the 

 iron, a third with a mixture of these, and the rest left untouched, 

 and afterwards put into a madder-vat ; the first will become red, 

 the second black, the third purple violet, chocolate, or lilac, ac- 

 cording to the proportions, and that part uncovered will be red- 

 dish, but which, on keeping it in bran a little fermented, and then 

 exposing it on the field, disappears, leaving the ground white. 



" That different colors can be given in this way, is easily shewn 

 by a simple experiment : Cover one part of a piece of cloth with 

 a solution of prussiate of potassa, and another with infusion of log- 

 wood, and leave the rest uncovered. When dry, put it into a so- 

 lution of green vitriol ; the first will become blue, the second 

 black, and the ground will be left white. 



" Connected with the art of dyeing is that by which bandannas 

 are made. For this purpose, a web is dyed Turkey red, and after 

 being laid up in folds, is placed between metallic plates, in which 

 are cut patterns, similar to that to be given to the cloth. Through 

 the holes thus cut in the plates, a solution of the bleaching com- 

 pound is allowed to flow, by which the color of that part of the 

 cloth is discharged, and a white pattern is left on the red ground." 



