For the purpose of paying them every attention an affectionate mother is provided, who is careful to supply their wants; she is called Isan-mon, ‘mother of the worms.’ She takes possession of the chamber, but not before she has washed herself and put on clean clothes, which have not the least repulsive smell; she must not have eaten anything immediately before, or handled any wild succory, the smell of which is very prejudicial. She must be clothed in a plain habit, without any lining, that she may be more sensible of the warmth of the place, and accordingly increase or lessen the fire. She must also carefully avoid making a smoke or raising a dust, which would also be offensive.”
Silk-worms require to be carefully humored before the time of casting their slough. Every day is to them a year, having in a manner, the four seasons; the morning being the Spring; the middle of the day: Summer; the evening: Autumn; and the night, Winter.
The chambers are so contrived as to admit of the use of artificial heat when necessary. Great care is taken of the sheets of paper on which the eggs have been laid; and the hatching is either retarded or advanced, by the application of cold or heat according to circumstances, so as to time the simultaneous exit of the young worms exactly to the period when the tender spring-leaves of the mulberry are most fit for their nourishment.
They proportion the food very exactly to the young worms by weighing the leaves, which in the first instance are cut, but as the insects become larger, are given to them whole. The greatest precautions being observed in regulating the temperature of the apartments. The worms are fed upon a species of small hurdles of basket-work, strewed with leaves, which are constantly shifted for the sake of cleanliness, the insects readily moving off to a fresh hurdle with new leaves, as the scent attracts them. In proportion to their growth, room is afforded to them by increasing the number of these hurdles, the worms of one being shifted to three, then to six, and so on until they attain their greatest size. When they have cast their several skins, reached their greatest size, and assumed a transparent yellowish color, they are removed to places divided into compartments, preparatory to casting forth their silken filaments.
In the course of a week after the commencement of this operation, the cocoons are complete, and it now becomes necessary to take them in hand before the pupæ turn into moths, which would immediately bore their way out, and spoil the cocoons. When a certain number, therefore, have been laid aside for the sake of future eggs, the chrysalides are killed by being placed in jars under layers of salt and leaves, with a complete exclusion of air. They are subsequently placed in moderately warm water, which dissolves the glutinous substance that binds the silk together, and the filament is wound off upon reels. This is put up in bundles of a certain size and weight, and either becomes an article of merchandise under the name of “raw silk,” or is subjected to the loom, and manufactured into various stuffs, for home or foreign consumption. The Chinese notwithstanding the simplicity of their looms (see [frontispiece]), will imitate exactly the newest and most elegant patterns from France. They particularly excel in the production of damasks, figured-satins, and embroidery. Their crape has never yet been perfectly imitated; and they make a species of washing silk, called at Canton “ponge,” which, the longer it is used, the softer it becomes.
The Chinese have from time immemorial been celebrated for the beauty of their embroideries; indeed, it has been doubted whether the art was not originally introduced into Europe by them, through the Persians.
From what has been said, it is evident that the raising of the mulberry-tree should first engage the attention of the cultivator, since its leaves form the almost exclusive nourishment of the silk-worm. It is scarcely necessary that we should in a work of this description enter more fully into the cultivation of the mulberry-tree. This has already been so ably done by Jonathan Cobb, Esq. of Dedham, Mass., Dr. Pascalis of New York, Judge Comstock of Hartford, Conn., and E. P. Roberts, Esq. of Baltimore, as to leave no stone unturned, or any want upon the subject.
In such parts of the Chinese empire where the climate is favorable to the practice, and where alone, most probably, the silk-worm is indigenous, it remains at liberty, feeding on the leaves of its native mulberry-tree, and going through all its mutations among the branches, uncontrolled by the hand and unassisted by the cares of man. As soon, however, as the silken balls have been constructed, they are appropriated by the universal usurper, who spares only the few required to reproduce their numbers, and thus furnish him with successive harvests[137].
[137] Mons. Marteloy of Montpelier, who made many experiments upon the rearing of silk-worms, presented a memorial upon the subject to the French minister, in compliance with whose recommendation, a few silk growers of Languedoc caused an experiment to be publicly made in the open air, in the garden belonging to the Jesuits’ college at Montpelier. The whole was placed under the direction of Mons. Marteloy, who had 1200 livres assigned to him to defray the necessary expenses. The experiment succeeded perfectly. This was in 1764. In the following year a second trial was made, and 1800 livres were set apart for the expenses. Owing, however, to the unfavorable nature of the season, this experiment failed entirely, the heavy and incessant rains making it impossible to keep the food of the worms in a sufficiently dry state. The rearing of silk-worms in the open air was not again attempted in that quarter; but the partial success led to the adoption among cultivators of a better system of ventilation, and the production of silk was about this time very much extended throughout Languedoc.—Obs. on the Culture of Silk, by A. Stephenson.
This silk, the spontaneous offering of nature, is not, however, equal in fineness to that produced by worms under shelter, and whose progressions are influenced by careful management. Much attention is, therefore, bestowed by the Chinese in the artificial rearing of silk-worms. One of their principal cares, is to prevent the too early hatching of the eggs, to which the nature of the climate so strongly disposes them. The mode of insuring the requisite delay, is, to cause the moth to deposit her eggs on large sheets of paper: these, immediately upon their production, are suspended from a beam in the room, while the windows are opened to expose them to the air. In a few days the papers are taken down and rolled loosely up with the eggs inside, in which form they are again hung during the remainder of the summer and autumn. Towards the end of the year they are immersed in cold water wherein a small portion of salt has been dissolved. In this state the eggs are left during two days; and on being taken from the salt and water are first hung to dry, and then rolled up rather more tightly than before, each sheet of paper being thereafter inclosed in a separate earthen vessel. Some persons, who are exceedingly particular in their processes, use a lye made of mulberry-tree ashes, and place the eggs likewise, during some minutes, on snow-water.