The dyeing of textile fabrics . Pig. 15.—Microscopic Appearance of Raw Silk Fibre. denser, while the innermost one, which immediately pro-tects the animal, forms a thin parchment-like skin. Theegg-shaped product is called a cocoon (Fig. 16). It ismade up of a double fibre, only rarely broken, varyingin length from 350 to 1,250 metres, and w^ith a diameterof about 0*018 millimetre. Each fibre is thickest in theoutermost portion of the cocoon, and becomes thinner. Chap. TV.] SILK COCOON. 47 towards the interior, owing to the exhaustion of the cater-pillar from want of food during the spinning pr
The dyeing of textile fabrics . Pig. 15.—Microscopic Appearance of Raw Silk Fibre. denser, while the innermost one, which immediately pro-tects the animal, forms a thin parchment-like skin. Theegg-shaped product is called a cocoon (Fig. 16). It ismade up of a double fibre, only rarely broken, varyingin length from 350 to 1,250 metres, and w^ith a diameterof about 0*018 millimetre. Each fibre is thickest in theoutermost portion of the cocoon, and becomes thinner. Chap. TV.] SILK COCOON. 47 towards the interior, owing to the exhaustion of the cater-pillar from want of food during the spinning process. The cocoons are white or yellow, contracted in thecentre, about 3 centimetres long, and 1 5—2 centimetresthick. As soon as the metamorphosis of the caterpillar intotiie chrysalis state is comj)leted, the cocoons are which are intended for breeding purposes areleft to themselves in a room heated to 19^—20^ C. Threeweeks after the spinning of thecocoon, the silk moth, whichhas now been formed in theinterior, emits a peculiar kindof saliva; with this the animalsoftens one end of the cocoon,and pushes its way out. A fewdays after the females have laid Fig. 16.—Silk eggs they die, not being provided with any organ of nutrition. The eggs areslowly dried, and stored in glass bottles in a dry darkplace till the following spring. Experience has shown that the worms issuing from 100gi-ams of eggs consume 3,500—5,000 kilo
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectdyesanddyeing, bookye
