H. E. Falk furnishes the following list of salt exports from the Mersey : SILK (Fn., Soie; GER., Beide).
Tho term " silk '' is employed to denote the fibrous material produced by a number of insects fer the purpose of forming a " cocoon " or nest in which a certain period of their existence is passed. Tho material composing thia fibre is called " aerisine," and is a product of the insect itself, exhibiting slight variations according to the species, and according to the food. It is the strongest, the most lustrous, and the most expensive of all organic fibrea.
RAISING.—Hence, the cultivation of the worms which produce the fibre has attracted attention from time immemorial, and silk-raising is one of the most profitable industries that enn be under taken in suitable climates. The first step in sericiculture is to aecure a supply of food for the wornis. For this purpose, the leaves of the mulberry seem to be unequalled. There are many species and varieties from which to choose, and preference should always be given when possible to that whose leaves afford the best sustenance to the worms, o.s indicated by their own predilec tions. Spotted and mildewed leaves must be avoided, and great care muat be taken that the leaves are aupplied fresh, dry, and clean, and particularly not heated or fermented. The points to be borne in mind in arranging a magmmerie or silkworm nursery are as follows :—A free circulation of air, without draughts, the windows never being opened on the windward side, except in the tropics ; plenty of light, but no actual sunshine in hot climates; avoidance of all scents and odours, whether pleasant or otherwise, and of all noise ; the temperature and moiature of the atmosphere of the chamber must he carefully watched and regulated. Electrical disturbances induce a kind of dysentery or cholera in the worms, which disease can only be stamped out by killing all the afflicted worms and all those whioh have been in contact with their excreta, as well as removing all excreta-stained leaves, nets, Ste. Another disease, which has become a serious epidemic, ia im
mediately caused by a fungus, called Panhistophyton; its germa n)ay be discovered as microscopic e3liodrical corpuscules in the blood of infected worms. Hence the necessity for thorough microscopic examination of every pair of moths before their eggs may be considered sound. The exami nation may he made after the moths nre dead and dried, by grinding them into a paste with a little water.
This syateln of microscopic selection should he rigidly adhered to. Before removing the silk from the cocoon, it is necessary to kill the chryoalis inhabiting it. This may be done by placing it in an oven at a temperature not exceeding 93° (200° F.) ; but a much superior plan is to subject it for a fow minutes to dry steam, which has a cleansing action upon the silk, and does not at the same time make it brittle.
Tho silk of which the cocoon ia formed is one solid thread of great length (even 500 yd.), which has been wound from the outside towards the centre, and diminishes in size as it proceeds, till reduced to A or A. It is detached and prepared for use by a process termed " reeling." There is always a certain portion left which cannot be reeled ; this may be carded and spun. With this objeet, large quantities of " busks " or "knubs,'' as tho waste cocoons are called, are exported to Europa from the great silk-growing countries of the East, and the product thus obtained is known as silk " waste." Reeling is an operation requiring considerable practice and skill for its proper performance. There are several handy machines in the market for the purpose, and choice should be made of one of slow motion for beginners.
lt may he useful to state that Chinese silk, by far the most important commercially, is put up in hales of the following weights :—Fine raw silk, 80 catties (of lA lb.); raw wild silk, 1 picul (of 1:3:1A lb.); hydraulio-pressed waste silk, 2 piculs ; cocoons, piculs.