So great is the importance of _silk_, in a commercial view, that, in most of the Eastern countries of the world, a close attention is paid to the growth and cultivation of the insects by which it is produced. Each moth lays about two hundred small straw-coloured eggs. As soon as the worms are hatched they are fed with the tenderest leaves of the mulberry-tree, or with these leaves chopped very fine; and, when they have attained sufficient strength, they are removed into wicker baskets, or placed upon shelves made of wickerwork. Here they feed for about thirty days, until they are full grown, when they are furnished with little bushes of heath or broom. On these they spin the nests in which they are about to change into chrysalids. These nests have the general name of coccoons, and consist of somewhat oval-shaped balls of silk, of marigold colour. The exterior of the coccoon is composed of a rough cotton-like substance, called _floss_. Within this is the thread, which is more distinct and even; and appears arranged in a very irregular manner, winding off first from one side of the coccoon, and then from the other. Previously to the silk being wound from the coccoons they are baked for about an hour to kill the chrysalids they contain. When the silk is to be wound off, the coccoons are put into small coppers or basins, of water, each placed over a small fire. The ends of the threads are found by brushing the coccoons gently with a whisk made for the purpose; and so fine are these threads that eight or ten of them are generally rolled off into one. In winding them, they are each passed through a hole in an horizontal iron bar placed at the edge of the basin, which prevents them from being entangled. The art of manufacturing silk was known to the ancients; but in Europe this commodity, long after its invention, was of very great value. We are informed that, in the third century, the wife of the Roman Emperor Aurelian entreated him to give her a robe of purple silk, and that he refused this under an allegation that he could not buy such a robe for its weight in gold.