James I. was solicitous to promote the breeding and rearing of silk worm; in England ; and in 1603 issued circular letters, which were addressed to persons of influence throughout the country, recommend ing the subject to them ; but the experiment was unsuccessful. Most of the old mulberry trees found in the neighbourhood of ancient mansions in England at. the present day were planted at this period. The experiment has also failed, though several times attempted, in North America.
The production of raw silk is fast extending in British India, and the quality has been for some years gradually improving. In Graham's ' it is said that in the Deccan the mulberry-trees may be deprived of their leaves six times a year, and that FRE crops of worms may be obtained with ease in the same period. The Chinese method of rearing silk-worms, and their mode of treating the mulberry-tree (described in Davis's "China,' p. 280), were introduced at St. Helena, under the auspices of the East India Company ; but on the expiration of their charter the establishment was given up. Some of the silk produced in France is believed to be better than that of any other country in the world. The Italian silk is also highly esteemed.
There has recently been a very earnest attempt made to disseminate the silk-worm culture in various parts of Europe. In 1854 some silk worm eo.s, reared at Assam, were brought from Calcutta to Malta, through the aid of Mr. Piddington. They were not the usual kind, but a variety called the Bombyx cy nthia, which feeds on the castor-oil plant. Sir William Reid, Governor of Malta, caused these eggs to be carefully tended ; 500 of them were hatched, and fed on the castor-oil plant. After some time, portions of the store were sent to Piedmont, France, Algiers, and the West Indies, in order that fair trials might be made in different climates. It is known that the castor-oil plant suffices to give the worms the silk-producing power; for the Assamese make shawls, dhoties, coverlets, coats, turbans, and women's dresses, with silk thus obtained. Early in 1855 it was found that the warms at Malta declined and died off, from some canoe not clearly traceable ; and the attempt failed, so far as that island was concerned. In 1854, however, some of the eggs reached Prussia; and great endeavours are now being made to foster the culture in Germany, Sweden, and Russia. The silk produced by this kind of worm is not so fine as the mulberry silk ; but is believed to be more easily worked, if the insect can only be made to thrive. As to England, silk-werm rearing has been to the present day, and still is, nothing more than an amusement, or an experiment having no commercial value.
This may be the proper place to say a few words concerning other filaments of the nature of silk. The web of many kinds of caterpillars has been found nearly equal to silk, and gloves and stockings have been made of it ; but Reitumur found that 50,000 of the insects were needed to yield 1 lb. of silk, and, moreover, that the caterpillars showed a very- unprofitable tendency to kill and eat each other. Some fabrics exquisitely light, others moderately strong, have been made from caterpillar filament, but hitherto without commercial success.
The pinna, a gigautic kind of mussel found in the Mediterranean awl the Indian Ocean, fastens itself to rocks with a kind of cord made of beautiful silky filaments; these filaments may be worked up in the manner of silk; hut the supply is too small to render the matter other than a curiosity. Very recently there was landed at Liverpool a small quantity of pulu or vegetable silk, obtained from the lower part of the stalk of a fern growing in Sumatra; the stalk is covered with a kind of sparkling golden-brown hair, which can be detached and worked up as silk. About 3 ounces can be obtained from each plant. The substance has not yet attracted much attention in England, but is beginning to be worked in America.
The Cocoons and Silk Reeling.—The cocoons [Ilolinvcime, in NAT. HIST. Div.] average iu weight about 3 grains each ; the average length' of silk upou each, when reeled off, is about 300 yards; and 12 lbs. of cocoons are required to yield 1 lb. of reeled silk—so many are the impurities to be got rid of. About 1 ounce of silk-worm eggs will produce 100 lbs. of cocoons; 16 lbs. of mulberry leaves will afford food sufficient for the production of 1 lb. of cocoons; and each mulberry tree will yield about 100 lbs. of leaves. These figures will afford easy means of calculating the number of insects, eggs, trees, leaves, &c., necessary for the production of 6,000,000 or 8,000,000 lbs. of silk— about the annual consumption of the United Kingdom. Reeling, or the drawing off of the silken filament from the cocoon, is usually done only in the countries where the worm is reared. To effect this, the worm is not allowed to die a natural death ; the cocoon is exposed to the heat of the saw or of an oven until the insect is stifled. An external soft envelope is removed, constituting floss silk ; the real silk is wound closely around the cocoon, in an agglutinated mass. The cocoons are steeped in hot water until the gum is dissolved. The reeler (a woman or girl), with a kind of whisk or brush, detaches the ends, of ten or twenty filaments from as many cocoons, winds them two or three together on a reel, then two or three of these groups together, and AO on until all form one thread, very much thicker than the original filament, but still exceedingly fine. New cocoons are thrown Into the vearel of hot water as fast as the old ones are ex• hausted, so that the thread Is made continuous ; and the temperature of the water is such AR will enable the cocoons to give off the filaments' past as fast as the reeler can wind them. In some districts the reeling is done in a quicker and better way, by aid of the apparatus shown In fig. I (plan), and fig. 2 (section). from the reel the silk is made np into hawks, which present different appearances, according to the countries' whole° they are obtained. Browse and China hank•, are whiter than the others; Bengal banks are email; Italian are larger ; and Persian are the largest and coarsest of all.