by exposure to the air, they soon acquire a blackish hue. Other spider bags might probably be found of different colors, and affording silk of better quality, but their scarcity would render any experiment with them difficult of accomplishment; for which reason M. Bon confined his attention to the bags of the common sort of the short-legged kind.
These always form their bags in some place sheltered from the wind and rain, such as the hollow trunks of trees, the corners of windows or vaults, or under the eaves of houses. A quantity of the bags was collected from which a new kind of silk was made, said to be in no respect inferior to the produce of the silk-worm. It took readily all kinds of dyes, and might have been wrought into any description of silken fabric. Mr. Bon had stockings and gloves made from it, some of which he presented to the Royal Academy of Paris, and others he transmitted to the Royal Society of London.
This silk was prepared in the following manner:—Twelve or thirteen ounces of the bags were beaten with a stick, until they became entirely freed from dust. They were next washed in warm water, which was continually changed, until it no longer became clouded or discolored by the bags under process. After this they were steeped in a large quantity of water wherein soap, saltpetre, and gum-arabic had been dissolved. The whole was then gently boiled during three hours, after which the bags were rinsed in clear warm water to discharge the soap. They were finally set out to dry, previous to the operation of carding, which was then performed with cards differing from those usually employed with silk, being much finer. By these means silk of a peculiar ash color was obtained, which was spun without difficulty. Mr. Bon affirmed that the thread was both stronger and finer than common silk, and that therefore fabrics similar to those made with the latter material might be manufactured from this, there being no reason for doubting that it would stand any trials of the loom, after having undergone those of the stocking frame.
The only obstacle, therefore, which appeared to prevent the establishing of any considerable manufacture from these spider bags was the difficulty of obtaining them in sufficient abund-
