SILK MANUFACTURE 785 



earnestly recommended his subjects to plant mulberry-trees ; but he totally failed 

 in the project. This country does not seem well adapted for this species of 

 husbandry, on account of the great prevalence of blighting east winds during the 

 months of April and May, when the worms require a plentiful supply of mulberry- 

 leaves. The manufacture of silk goods, however, made great progress during that 

 king's peaceful and pompous reign. In 1629 it had become so considerable in London 

 that the silk-throwsters of the city and suburbs were formed into a public corporation. 

 So early as 1661 they employed 40,000 persons. The revocation of the Edict of 

 Nantes, in 1685, contributed in a remarkable manner to the increase of the English 

 silk trade, by the influx of a large colony of skilful French weavers, who settled in 

 Spitalfields. The great silk-throwing mill mounted at Derby, in 1719, also served to 

 promote the extension of this branch of manufacture ; for soon afterwards, in the year 

 1730, the English silk goods bore a higher price in Italy than those made by the 

 Italians, according to the testimony of Keysler. 



The ordinary silkworm, called by entomologists Bombyx mori, is, like its kindred 

 species, subject to four metamorphoses. The egg, fostered by the genial warmth of 

 spring, sends forth a caterpillar, which, in its progressive enlargement, casts its skin 

 either three or four times, according to the variety of the insect. Having acquired its 

 full size in the course of 25 or 30 days, and ceasing to eat during the remainder 

 of its life, it begins to discharge a viscid secretion, in the form of twin filaments, 

 from tubes opening on the under lip, which harden in the air. These threads are 

 coiled into an ovoid nest round itself, called a cocoon, which serves as a defence 

 against living enemies and changes of temperature. Here it soon changes into the 

 chrysalis or nymph state, in which it lies swaddled, as it were, for about 15 or 20 

 days. Then it bursts its cerements, and comes forth furnished with appropriate 

 wings, antennae, and feet, for living in its new element, the atmosphere. The male and 

 the female moths couple together at this time, and terminate their union by a speedy 

 death, their whole existence being limited to two months. The cocoons are com- 

 pletely formed in the course of three or four days ; the finest being reserved as seed- 

 worms. From these cocoons, after an interval of 18 'or 20 days, the moth makes its 

 appearance, perforating its tomb by knocking with its head against one end of the 

 cocoon, after softening it with saliva, and thus rendering the filaments more easily, 

 torn asunder by its claws. Such moths or aurelias are collected and placed upon a 

 piece of soft cloth, where they couple and lay their eggs. 



The eggs, or grains as they are usually termed, are enveloped in a liquid which 

 causes them to adhere to the piece of cloth or paper on which the female lays them. 

 From this glue they are readily freed, by dipping them in cold water, and wiping 

 them dry. They are best preserved in the ovum state at a temperature of about 55 F. 

 If the heat of spring advances rapidly in April, it must not be suffered to act on the 

 eggs, otherwise it might hatch the caterpillars long before the mulberry has sent forth 

 its leaves to nourish them. Another reason for keeping back their incubation is, that 

 they may be hatched together in large broods, and not by small numbers in succes- 

 sion. The eggs are made up into small packets, of an ounce, or somewhat more, 

 which in the south of France are generally attached to the girdles of the women 

 during the clay, aiid placed under their pillows at night. They are, of course, care- 

 fully examined from time to time. In large establishments, they are placed in an 

 appropriate stove-room, where they are exposed to a temperature gradually increased 

 till it reaches the 86th degree of Fahrenheit's scale, which temperature it must not 

 exceed. Aided by this heat, nature completes her mysterious work of incubation in 

 eight or ten days. The teeming eggs are now covered with a sheet of paper pierced 

 with numerous holes, about ^th of an inch in diameter. Through these apertures the 

 new-hatched worms creep upwards instinctively, to get at the tender mulberry-leaves 

 strewed over the paper. 



The nursery where the worms are reared is called by the French a magnaniere ; it 

 ought to be a well-aired chamber, free from damp, excess of cold or heat, rats and 

 other vermin. It should be ventilated occasionally, to purify the atmosphere from 

 the noisome emanations produced by the excrements of the caterpillars and the decayed 

 leaves. The scaffolding of the wicker-work shelves should be substantial ; and they 

 should be from 15 to 18 inches apart. A separate small apartment should be allotted 

 to the sickly worms. Immediately before each moulting, the appetite of the worms 

 begins to flag ; it ceases altogether at that period of cutaneous metamorphosis, but 

 revives speedily after the skin is fairly cast, because the internal parts of the animal 

 are thereby allowed freely to develope themselves. At the end of the second age, 

 the worms are half an inch long; and should then be transferred from the small room 

 in which they were first hatched, into the proper apartment where they are to be 

 brought to maturity and set to spin their balls. On occasion of changing their abode, 

 they must be well cleansed from the litter, laid upon beds of fresh leaves, and supplied 

 VOL. III. 3 E 



