from China to Central Asia and India. The Greeks acquired some information about silk during the reign of Alexander the Great, and his conquests in the East led to closer relationship between Europe and Asia, so that at the beginning of the Christian era a prosperous trade opened up, and Chinese silks were carried to Rome by way of Persia and Syria along the old caravan routes of Central Asia.
Since these days the manufacture of fine fabrics from raw silk has become highly industrialised and countries famous for their produce include India, China, Persia, France, Italy and America.
THE PRODUCTION OF RAW SILKWe have all heard about the Chinese pet, the contented silkworm. The Chinese have been looking after him to the last rite, by art and by ritual, since 2640 B.C., but it certainly took the Japanese to put him on a commercial basis.
The silk-moths (a, Fig. 5) lay grey eggs the size of poppy seeds once a year—in the summer. These eggs are stored in cool rooms, in order to prevent too early hatching. Only when the leaves of the mulberry tree—the food of the silkworms—have grown, are the eggs taken to a warmer temperature. This takes place in the following spring, and here their development—shown by a whitish discoloration—begins. After about ten days, small, brownish caterpillars approximately 1⁄12 inch in length, leave their eggs and at once eat their first food, which consists of delicate, fresh mulberry leaves. The silkworm, growing rapidly, changes its skin four times, once every sixth day, and already, after a month, it will have reached the considerable length of approximately 3½ inches. How immense this growing is, may be realised by comparison with that of a baby who, developing at a similar rate, would after a month be as big as a church spire!
About five days after the fourth changing of the skin, the silkworm, having attained its maximum length, ceases to eat, and becoming restless, begins to swing its head to and fro with a strange, oscillating movement. This is a sign that it wants to spin a cocoon and it accordingly looks for a suitable place (prepared for it between faggots or wisps of straw) (b), usually