Scientific American Supplement, No. 620, November 19,1887 by Various
page 32 of 138 (23%)
page 32 of 138 (23%)
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laying on the filament in a succession of lines somewhat resembling
the shape of the figure eight. As the worm continues the work of making its cocoon, the filament expressed from its body in the manner described is deposited in nearly even layers all over the interior of the wall of the cocoon, which gradually becomes thicker and harder. The filament issuing from the spinnarets is immediately attached to that already in place by means of the gum which has been mentioned. When the store of silk in the body of the worm is exhausted, the cocoon is finished, and the worm, once more shedding its skin, becomes dormant and begins to undergo its change into a moth. It is at this point that its labors in the production of silk terminate and those of man begin. A certain number of the cocoons are set aside for reproduction. In southern countries the reproduction of silkworms is a vast industry to which great attention is given, and which receives important and regular aid from the government. It is, however, quite distinct from the manufacturing industry with which at present we have to do. The cocoons to be used for reeling, i.e., all but those which are reserved for reproduction, are in the first place "stifled," that is to say, they are put into a steam or other oven and the insect is killed. The cocoons are then ready for reeling, but those not to be used at once are allowed to dry. In this process, which is carried on for about two months, they lose about two-thirds of their weight, representing the water in the fresh chrysalis. The standard and dried cocoons form the raw material of the reeling mills, or filatures, as they are called on the Continent. Each filature endeavors as far as possible to collect, stifle, and dry the cocoons in its own neighborhood; but dried cocoons, nevertheless, give rise to an important commerce, having its center at Marseilles. The appearance of |
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