432

DYEING AND CALICO PRINTING.

violet-coloured cloth, which turned green on being washed in a boiling dilutesolution of alum. The green dye thus obtained lacked the brilliancy andintensity of the Chinese dyed cloth, but the reactions were the same, and,moreover, the cloth prepared by M. Michel had a wrong and right side, justas described for the Chinese cloth. The cloth dyed by M. Michel hadits right side there where it had been exposed to diffused light. There doesexist, therefore, in the Rhamnacete a peculiar substance, not yet isolated, whichhas the preperty of becoming green under the influence of the white diffuselight of the sky.

Green Dyeing.

The Chinese dye the woven tissues or yarns green either by making use ofthe barks already mentioned, in which case the dyed fabric has—as regardsthe colour—a right and wrong side, or they use the lo-kao, in which latter caseboth sides of the cloth are dyed alike : this difference is readily explained bythe researches of M. Michel, because, as regards the first case, there is fixedon the cloth a colourless but colourable matter, which does not develope itscolour but when exposed towards the light; in the second case, there is useda ready-formed pigment.

When the dyer desires to use the bark only, the following processes areused:—

a. Process of Khiu-tcheou-fou. —The fresh bark of pe-pi-lo-chou is boiled,

and to every ioo kilos, of the liquid are added 63 grins, of Chinese pot-, ash ; the cloth is immersed in the liquid from two to three times, anddried in the sun after immersion. At Chan-toung alum is used insteadof potash.

b. Process of Emou-i, as described by Mr. Sinclair. —The bark of Io-tse* is

placed in hot water, and next boiled for an hour; potash and alum areadded; the liquid is next decanted and filtered, and left standing overnight; the goods are next immersed in the bath, and after that dried byexposure to open air, the pieces being stretched out over the grass, butonly during the earlier hours of the day. This dyeing and drying ope-ration has to be repeated several times before the desired shade of colouris obtained.

Lo-kao is not used in China even for dyeing more common and coarse kindsof cotton goods, but only for bright colours. The pigment is dissolved in a hotsolution of potassa, and the previously well-washed cloth is immersed in thisbath, kept at a temperature of 50° or 6o°. Immediately after the first immer-sion the goods are wrung out by mechanical means, and the dyeing operationis repeated a second time, again followed by wringing out, and next a washingin fresh water and drying in the open air, which ends the proceedings. Thereis not the least doubt that the Chinese use lo-kao for silk-dyeing, and alsoapply the Rhamnus barks for that purpose, [but their process of operating isunknown.

The researches of Stanislas Julien, who was a resident in China for manyyears, have proved that the use of the lo-kao and the bark from which it is

* Although this word differs from that mentioned under a , the material is no doubt the same,it being a well-known fait tha£ there are very many dialedts in use in China, the extent of thatcountry exceeding fay one-third that of the United States of America, which measure fully3,500,000 square miles.