Large quantities of lac and tussur silk are gathered in the hilly tract.
There are indigo factories, and other industries include the weaving of tussur silk and the making of coarse glass.
The principal products are rice, oil-seeds, lac, tussur silk, horns, hides, wax and a little iron.
- Chinese Tussur Moth, yearly and producing a soft flossy cocoon; the Chinese monthly worm, B.
The most important of the species at the present time is the Chinese tussur or tasar worm, Antheraea pernyi (figs.
7, 8), an oakfeeding species, native of Mongolia, from which is derived the greater part of the so-called tussur silk now imported intoEurope.
On this account the fibres of tussur or tussore silk tend to split up into fine fibrillae under the various preparatory processes in manufacturing, and its riband structure is the cause of the glassy lustre peculiar to the woven and finished fibres.
The natural colour of tussur silk is a greyish fawn, and that shade it was found impossible to discharge by any of the ordinary bleaching agents, so as to obtain a basis for light and delicate dyes.
Moreover, the chemical character of the tussur silk differs from that of the mulberry silk, and the fibre has much less affinity for tinctorial substances, which it takes up unevenly, requiring a large amount of dye-stuffs.
After protracted experimenting Sir Thomas Wardle was able in 1873 to show a series of tussurs well dyed in all the darker shades of colour, but the lighter and bright blues, pinks, scarlets, &c., he could not produce, Subsequently Tessie du Motay found that the fawn colour of natural tussur could be discharged by solution of permanganate of potash, but the oxidizing action was so rapid and violent that it destroyed the fibre itself.
Gentler means of oxidation have since been found for bleaching tussur to a fairly pale ground.
The dark colours are very difficult to bleach, but the silk itself takes dye-colours much more freely and evenly than either tussur or eria silk.
The tussur silk industry is of considerable importance, and the silk is reputed the best in the Central Provinces.
The principal industry is the spinning and weaving of silk, chiefly from tussur or jungle silkworms. There are also several lac factories.
The article known as tussur spun is prepared in exactly the same manner as other spun silks, but its chief use is to make an imitation of sealskin known commercially as silk seal.