ever, not resisting the humidity, a kind called water.. bird-lime is used. It is prepared by washing, drying, and mixing the common kind with capon or goose grease, adding a little vinegar, oil, and turpentine, and boiling them slightly, after which it is used warm for snipes and other birds that frequent wet situations. The Damascus bird-lime can neither bear wet nor frost; the Spanish is good, but has an offensive smell; and that from Italy is chiefly made from the mistletoe. It may also be prepared from several worms and caterpil lars, according to the experiments of La Grange and others. (Tilloch's Philosoph. Magaz) Bird-lime is of a greenish colour, sour flavor, gluey, stringy, tenacious, elastic, and smells like linseed oil. It becomes dry and brown when exposed to the air, but not brittle, and consists of resin, mucilage, extractive mat. ter, and acetic acid, with very little, if any thing, of gluten, or animal matter. Natural Birdlime is found on the bark of the robinia viscosa.

All

CHARCOAL being calcined wood, and of vegetable origin, naturally follows the description of timber trees. The uses of charcoal for making powerful fires to melt metals, in the manufacture of gunpowder, polishing copper or brass, &c. are well known. charcoal is black and sonorous; by the microscope it is discovered to be very porous, and to this cause must be ascribed its colour, as the rays of light striking the charcoal are absorbed instead of being reflected: blackness in a body being occasioned by its want of reflective powers. Both the gravity and colour, however, of charcoal vary according to the species of timber, and the delicacy of the process of charring, some of it being lighter or heavier, brighter and more sparkling, or duller, than others. Charcoal, which is now ascertained to be nothing but wood deprived of all its volatile particles, is prepared in two ways; the first and most general is by cutting branches of trees or split stems into lengths of four feet, placing them either on a kind of kiln, or piling them up in a pyramidal form to carry on a slow combustion, by covering these piles with turf or moss, to prevent the imme diate consumption of the wood by the fire, which is introduced into a cavity in their centre, and supported

by air-holes, at different heights, with a chimney or vent at top for the ascent of the smoke. This slow burning is continued five or six days, and should the wood appear to be consuming at any point, the fire is there extinguished; or if the fire is too feeble, additional air-holes are made in the covering turf, till the whole Las ceased to emit smoke, after which the fire is extinguished by close covering, and the pile is allowed to cool very gradually. Good charcoal, retains the original shape of the wood, but is light and brittle: those pieces which are not sufficiently charred are called brands, and are used for setting fire to another pile. The second process is that of destructive distillation in an iron vessel, made red hot over a strong fire, by which means the gaseous or volatile contents of the Wood may be preserved, while the charcoal is esteemed more pure, and fitter for gunpowder. According to the experiments of the ingenious Mushet, related in the work quoted above, the following woods afforded from 16 to 26 parts in 100 of charcoal; thus, Scotch pine 16, birch, ash, sallow, Norway pine, elm, sycamore, American maple, holly, beech, walnut, Amer. ican black beech, oak, chesnut, laburnum, mahogany, (each increasing about 1) to lignum vitæ, which yielded 26.7

COKE being a mineral charcoal, prepared in the same way, and used for similar purposes, as the vege table, it is properly noticed here. The suffocating effects of charcoal or coke fires in factories, are rather to be attributed to the intense heat which they afford, than to the disengagement of carbonic acid gas, and to their want of a flame to carry off the soot which is generated, and produce a regular current of fresh air. If, indeed, regular currents of air were introduced, charcoal fires would not only be inoffensive, but more wholesome than those of coal, as they do not so suddenly transport so much soot and carbonaceous matter to the lungs. Charcoal and coke when perfectly pure, are called in chemical language, CARBON, and are virtually the same. Mr. Davy, by means of his immense Voltaic pile, has (June 1810) converted charcoal into permanent vapour or gas. Charcoal and soot are used

for blacks by painters and varnishers, and charcoal of willow' makes the best drawing crayons. It is also remarkable for resisting corruption, purifying water, cleaning the teeth, &c. &c.

CORAL AND SPONGE FISHERY.

CORAL is by some termed a marine plant, but it is really an animal. Kercher supposed that there are entire forests of it at the bottom of the sea; and Tour nefort maintained that it multiplied by sced, though neither its flowers nor seed were known. Count de Marfigli said he had discovered some parts which seemed to serve the purpose of seeds and flowers. The roots of the coral are covered with a bark, beset with starry pores. The tree part of the plant is divided into branches. Linnæus has classed coral among the zoophytes, which are a kind of intermediate bodies, supposed to partake both of the nature of the animal and vegetable kingdom. The genus isis, or coral, in the order of zoophytes, or composite animals, efflorescing like vegetables, is an animal in, the form of a plant, with a stony stem, jointed, and the joints longitudinally channelled, united by spongy or horny junctures, covered by a soft porous cellular flesh or bark, and having a mouth beset with oviparous polypes. In Cook's Voyages are described the immense and dangerous rocks built by the swarms of coral insects in the southern ocean, which rise perpendicularly like walls. The ancients erroneously believed that coral was soft while it continued at the bottom of the water, and that it became hard and solid by the impression of the air. There are three kinds; red, white, and black. The white is the rarest and most esteemed. The red is ordinarily used in medicine. It must be chosen thick, smooth, and shining, and of a beautiful red. It has been used as a medicine in various diseases, but the chief use of coral is in chaplets, beads, and other toys.

The places for fishing coral, are in the Persian Gulf, Red Sea, coast of Africa, the isles of Corsica and Ma jorca, and some parts of the Spanish coast. The time

for fishing, is from April to July. The method used under the direction of the company, at Marseilles, in France, is as follows. Seven or eight men go in a boat, commanded by the patron or proprietor; the caster throws his net, or machine, and the other six manage the boat. The net is composed of two beams tied across, with a leaden weight to press them down: to the beams is fastened a great quantity of hemp loosely twisted round, among which they mix some strong nets. In this condition the machine is let down into the sea, and when the coral is strongly embarrassed in the hemp and the nets they draw it out by a rope. It sometimes requires half a dozen boats to draw it up, and if the rope happen to break, the fishermen are in danger of drowning.

Artificial coral is made of cinnabar well beaten, a layer whereof is applied on a piece of wood, moistened with size, dried and polished, and lastly, rubbed over with the white of an egg.

SPONGE is a kind of marine animal, fixed, flexible, torpid, elastic, of various forms, composed either of reticulate fibres, or masses of small spines interwoven together, and clothed with a gelatinous flesh full of small mouths on its surface, by which it absorbs and rejects water. It is found adhering to rocks, shells, &c, under cover of sea water, and it is distinguished into coarse and fine. Naturalists were embarrassed whether to range sponge in the animal, mineral, or vegetable family. But it is now decidedly allowed to belong to the first, and to be a particular genus in the order of zoophytes. M. de Peysonnel has discovered and described the worms that form four different species of sponges he thinks the sponge is formed from the juice or slaver which is deposited by the worms that inhabit them. The greatest part of our sponges are brought from the Mediterranean, especially from Mica. ria, an island near the coast of Asia. Diving or fishing for sponge is there reckoned the chief qualification for youth. The fine or small sponges are most esteemed; and usually come to us from Constantinople. Their goodness consists in their being white, light, and the holes small and close; the larger and coarser come from

the coast of Barbary, particularly Tunis and Algiers. Sponge taken inwardly choaks, and certainly kills, by swelling, and preventing the passage of the food into the intestines. Sponge burnt and powdered has. been used as a remedy for scrofula. Corals, sponges, and all the numerous tribe of zoophytes, consist of gelatinous or albuminous matter hardened by different proportions of carbonat, or phosphat of lime.

CLOTH MANUFACTURES.

THE artificer must not here expect to find the exact weight or quantity of each ingredient, and the whole process most minutely described, from which he may 'make experiments. This work is compiled, not so much for the artificer or mechanic, as for the young scholar; and consequently it is intended to convey only general ideas, not particular and minute directions.

WOOL is the hair or covering of sheep, or other animals, which after being washed, shorn, dressed, combed, and spun, is woven into various kinds of stuffs and cloths, &c. for apparel and furniture. While the wool remains in the state it was first shorn off the sheep's back, and not sorted into its different kinds, it is called fleece. Each fleece consists of wool of different qualities and degrees of fineness. The finest grows on the pole of the sheep, the coarsest about the tail, the shortest on the head and on some parts of the belly, the longest on the flanks. Wool is either shorn, or pulled off the skin after the sheep are dead: this last sort is short and finer; if it be short it is used for hats, and not in the manufacture of cloth, unless mixed in fleeces. The French and English usually separate each fleece into three sorts, viz. 1st. Mother wool, which is that of the back and neck. 2d. The wool of the tail and legs. 3d. That of the breast and under the belly. The Spaniards call these three sorts, prime, second, thirds. Among the Spaniards, about one hundred and twenty-five shearmen are employed to shear a flock of ten thousand sheep. When shorn, the first thing is to weigh the wool; they next divide it into three sorts,