straw is put, The camphor is volatilized, and attaches itself to the straw. It is a little impure, but is purified in Europe by a second sublimation. The camphor of commerce, from its mode of preparation, is in the form of large semi-spherical cakes: when broken, it appears in fragments of a texture somewhat striated, having a degree of ductility, in consequence of which it can be compressed, and is not easily reduced to powder; of a white colour, and semitransparent; a little unctuous to the feel; having a very strong, peculiar, and rather fragrant odour, and a taste which is pungent and bitter. It is also susceptible of crystallization when slowly sublimed, or when slowly precipitated from its solution in wa+ ter by the affusion of alcohol, it appears in the form of acicular prisms, Camphor, though a concrete substance, is even more volatile than the essential oils. It evaporates quickly at the common temperature of the atmosphere, losing in weight, and an angular fragment becoming spherical; and at a temperature between 100 and 150, it sublimes in close vessels unchanged. It is highly inflammable, kindles very readily, and burns with the emission of much light, and with a dense black smoke, which condenses into a smooth light charcoal. Carbonic acid gas is produced, and a portion of the peculiar acid which has been named camphoric acid. Camphor is very sparingly soluble in water. When triturated with it, it merely communicates its smell and taste to the water, which remains odorous, and somewhat pungent, even when filtrated; but no appreciable quantity is dissolved. A phenomenon which has excited some attention is presented, when pieces of camphor are placed on the surface of pure water. They soon begin to move with rapidity, and while moving dissolve, the solution taking place at the line where the water and the air are in contact; as is proved by immers ing a cylinder of camphor in water part of its length: it becomes excavated, and at length is cut through, exactly on a level with the surface of the water. Camphor is abundantly soluble in alcohol: the solution is immediately decomposed, and the camphor precipitated in the form of a white powder, by the affusion of water; but if the water be very slowly added, and merely in such a quantity as to weaken the affinity of the alcohol to the camphor, the latter, in separating, presents a deutritic crystallization. It is also soluble in expressed and essential oils. The alkalis do not dissolve camphor, or produce in it any sensible change. Of the earths, magnesia appears to exert some action on it, as, when they are triturated together, the camphor is reduced to a smooth impalpable powder, which is easily diffused in water. The action of the stronger acids on camphor is peculiar, and presents some singular results. By distilling nitric acid from camphor, it is more completely changed, and by this process is converted into an acid which has received the name of camphoric acid. The process consists in distilling from four ounces of camphor in a retort, 1 lb. of ni tric acid, so far diluted as to be of the specific gravity of 1.33, the heat being gra dually applied by the medium of a sandbath nitric oxide and carbonic acid gases are disengaged; part of the camphor rises in vapour, while the other part receives oxygen from the acid. Camphoric acid, thus produced, is different from all the known acids. It has a slightly acid bitter taste, and reddens infu. sion of litmus. Its crystals effloresce on exposure to the air; they are sparingly soluble in cold water, an ounce of water at 50° of Fahrenheit not dissolving more than 6 grains; at 212°, about 48 grains are dissolved. When the acid is placed on ig. nited fuel, it emits a dense aromatic vapour, and is entirely dissipated. By ap. plying heat to it in close vessels, it first melts and sublimes, but by a higher heat its properties are changed; it no longer reddens litmus, acquires an aromatic smell, its taste is less penetrating, and it is no longer soluble in water, or in sulphuric or muriatic acid. Nitric acid heated on it turns it yellow and dissolves it. acids: it is likewise soluble in alcohol, and Camphoric acid is soluble in the mineral in the volatile and fixed oils. It produces this acid, with the alkaline, earthy, and no change in sulphur. The salts formed by Their properties have been examined by metallic bases, are named Camphorates. Lagrange. Their taste is somewhat bitter: they are decomposed by heat, the acid beflame when heated before the blow-pipe, ing sublimed: and they all exhibit a blue The alkaline and earthy camphorates are formed by adding the camphoric acid to the alkali or earth, either pure, or in the state latter case, being disengaged. of carbonate; the carbonic acid, in the ર See the preceding article. CAMPHORATES, 1 P A 甘 camphor of the shops is prepared, being a species of laurel. See LAURUS. CAMPHORASMA, in botany, from camphora, a genus of the Tetrandria Monogynia class and order. Natural order of Holoracea. Atriplices, Jussieu. Essential character: calyx pitcher-form, two of the teeth opposite, and the alternate ones very small; corolla none; capsule one-seeded. There are five species, of which C. monspeliaca, hairy camphorosma, is an annual plant, with trailing branches, extending a foot or more in length; leaves linear; the flowers are produced from the joints, and are so small as to be scarcely perceptible. Native of France and Spain. The whole plant smells of camphor; it abounds in a volatile oily salt, and is warm and stimulating. CAMUS, (CHARLES STEPHEN LEWIS) in biography, a celebrated French mathematician, was born at Cressy en Brie, the 25th of August, 1699. His early ingenuity in mechanics and his own intreaties induced his parents to send him to study at a college in Paris, at 10 years of age; where in the space of two years his progress was so great that he was able to give lessons in mathematics, and thus to defray his own expenses at the college without any farther charge to his friends. By the assistance of the celebrated Varignon this youth soon ran through the course of the higher mathematics, and acquired a name among the learned. He made himself more particularly known to the Academy of Sciences in 1727, by his memoir upon the subject of the prize which they had proposed for that year, viz. "To determine the most advantageous way of masting ships;" in consequence of which he was named, that year, Adjoint-Mechanician to the Academy; and in 1730 he was appointed Professor of Architecture. In less than three years after he was honoured with the secretaryship of the same; and the 18th of April, 1733, he obtained the degree of Associate in the Academy, where he distinguished himself greatly by his memoirs upon living forces, or bodies in motion acted upon by forces, on the figure of the teeth of wheels and pinions, on pump work, and several other ingenious memoirs. In 1736 he was sent, in company with Messrs. Clairaut, Maupertuis, and Monnier, upon the celebrated expedition to measure a degree at the north polar circle; in which he rendered himself highly useful, not only as a mathematician, but also as a mechanician and an artist, branches for which he had a remarkable talent. In 1741, he invented a gauging rod and sliding rule, by which the contents of all kinds of casks might be immediately ascertained. He was employed in works of importance in his own country, and elected Geometrician in the French Academy. In 1765 he was chosen a Fellow of the Royal Society of London. On the 4th of May, 1768, he died in his 69th year, and was succeeded in his office of Geometrician to the Academy by D'Alembert. His works are numerous and of great reputation: the principal are "A Course of Mathematics," "Elements of Mechanics,” and “Elements of Arithmetic." CANAL, an aqueduct made for the purposes of inland navigation. This great improvement in the conveyance of commodities has arrived at a high degree of perfection, and enables us to transport them even over mountains where it would appear impossible to preserve a communication, or rather a continuity of water carriage with the subjacent plains. This is effected by the means of locks built of masonry, each of which serves as the conjunction of two different levels. The locks are made only large enough to admit the vessels employed in the business, and have two gates, one at each end. When a vessel should ascend to a superior level, the upper gate is shut, and the vessel being brought within the lock, the lower gate is also closed, and the upper one opened. By this means the water flows in, and the vessel is raised to the intended height. The upper gate is closed as soon as the vessel has passed, but the water in the lock is preserved for the purpose of letting a vessel down, which is done by shutting the upper gate after she is in the lock, and opening the lower one; so that she is lowered gradually to the next level. The water in all cases is let in or out by means of a small hatch, making its rise and fall very gradual; else the gates would be torn from their hinges by the rush of so large a body, and the vessel would be endanger. ed. We have instances of about twenty locks all in half a mile's distance; but there require very powerful springs to supply a due quantity of water. Sometimes canals are raised above the level of the country; and we have instances where one canal passes over another. The particular operations necessary for making artificial navigations, depend upon a number of circumstances. The situation of the ground; its vicinity or connection with rivers; the ease or difficulty with which a proper quantity of water can be obtained: these, and many other circumstances, necessarily produce great variety in the structure of artificial navigations, and augment or diminish the labour and expense of executing them. When the ground is naturally level, and unconnected with rivers, the execution is easy, and the navigation is not liable to be disturbed by floods; but when the ground rises and falls, and cannot be reduced to a level, artificial methods of raising and lowering vessels must be employed, which likewise vary according to circumstances. In Mr. Donaldson's "View of the Present State of Husbandry," it is observed, that the canals already completed or forming have had wonderful effects upon the agriculture, as well as upon the manufactures and general state of many parts of the kingdom; these, and the navigable rivers, render the carriage of bulky articles more easy and less expensive. The conveyance of manure, fuel, &c. into districts whither, without that medium, they could scarcely have been transmitted, has tended materially to the improvement of these particular districts; and the ease with which the inhabitants can export the produce of the country to otherwise almost inaccessible markets, while it tends to the same end, has also considerable effects on the general markets of the kingdom, and lessons the number of horses that would be requisite for transporting these articles from one place to another. Owing to some cause or other, inland navigations in many parts of the island have proved ruinous to the adjoining lands; while, in many others, the injury done to the soil in the districts through which these inland navigations are carried, by obstructing the free passage of the rivers to the sea, and by their frequently overflowing their banks, and destroying the crops in the low grounds, is infinitely greater than any commercial advantages that can possibly be derived from them, except by those who are more immediately interested. To render canals, or inland navigations of any sort, of general utility, says he, much circumspection is necessary in framing the acts of Parliament; so that while the commerce of the country is increased, its agriculture may not be injured. It might, he thinks, be a wise regulation, that in every instance without exception, all sorts of manure should be carried at one half or one third of lockage-dues made payable for articles of any other description. Were this point attended to, and minute investigation made as to the probable consequences that were likely to result from granting leave to form canals, and deepen the beds of rivers, for the purpose of inland navigations, these means of lessening the expense of carriage would not so often prove injurious to the best interest of the country,-its agricultural improvement. It has been well observed by Mr. Middleton, in his able Survey of Middlesex, that "canals calculated to navigate much smaller boats than any which have fallen under his observation, even down to ten tons, might be made at a very reduced expense; and after certain leading ones were executed, every man of considerable landed property would find it to be his interest to make a small canal through his estate, at least capable of floating boats of five tons, which would be equally convenient for bringing manure, and to carry away the produce. In all the marsh and fen districts, most of the present sewers would only want," he thinks, "a little cleansing to fit them for this purpose." And he adds, that "the extension of canals may become the most powerful means of promoting general cultivation. Good roads are certainly very essential, and he thinks canals are at least equally so, in an agricultural view. On the best roads, produce and manure can seldom be carried more than ten miles with profit, at the present price of horse-keep; but if canals were as numerous as roads, corn, hay, manure, &c. could be sent to every part of Britain, without using more road than the towing-paths, and to ten times the former distance without increasing the expense. A general canal-scheme would, says he, tend to equalize the price of every article in life more than all other things put together. It would afford the cheapest, the safest, and speediest conveyance of every article that might be too bulky and heavy for stage and mail coaches. The benefits would be universal in this island. The inhabitants of London and its environs would be infinitely more plentifully and cheaply supplied by canals than by any system of roads whatsoever. The remoter parts of this, and every other country, would be placed more on terms of equality with those that are near, and every other part of the island might reap advantages which may be foreseen, but which are much too great for calculation." And he concludes by remarking, that "canals and irrigation might be made the means of cultivating every inch of this island, except rocky ground and mountain tops, and these ought to be planted." He states, that "of two methods of raising the money for making canals, the one which seems to deserve the preference is, the mode by which turnpike roads are usually provided for, instead of entrusting it to the management of interested companies. The latter method is exceptionable, from its creating a perpetual charge on all goods sent by that conveyance, without regarding the money expended, or the interest it may ultimately produce, which is a very imprudent bargain for the public in this country, where population, trade, manufactures, and commerce are so much upon the increase." CANARINA, in botany, a genus of the Hexandria Monogynia class and order. Natural order of Campanacea. Campanula ceæ, Jussieu. Essential character: calyx six-leaved; corolla six-cleft, bell-form; stigmas six; capsule inferior, six-celled, many-seeded. There are two species, of which C. campanula, Canary bell flower, has a perennial root; stem three feet high; corolla resembling that of a crown imperial, with a yellow eye; style club-form. Native of the Canary Islands. CANARIUM, in botany, a genus of the Dioecia Pentandria class and order. Essential character: male, calyx two-leaved; corolla three-petalled: female, calyx twoleaved; corolla three-petalled ; stigma sessile; drupe with a three-cornered nut. There is but one species; viz. C. commune. This tree is a native of the Molucca islands, Banda, and New Guinea. The nuts are eaten both raw and dressed by the inhabitants; an oil is expressed from them, which is used at the table when fresh, and for lamps when stale: bread is also made from them, cakes, biscuits, &c. for the table. CANARY bird. See FRINGILLA. CANCER, in astronomy, one of the twelve signs of the zodiac, represented on the globe in the form of a crab, and thus marked () in books. See ASTRONOMY. CANCER, tropic of, in astronomy, a lesser circle of the sphere parallel to the equator, and passing through the beginning of the sign Cancer. CANCER, the crab, in natural history, a genus of insects of the order Aptera. The generic character: eight legs in general, sometimes six or ten, besides two chelated arms; two eyes, distant, in general footstalked, elongated, and moveable; tail un armed, and jointed. Animals of this genus at particular periods cast their shells, previously to which the limbs shrink, to facilitate their extrication. The loss of a limb, with other animals irreparable, is of little consequence to these, as a few weeks suffice to reproduce one: and in cases of bruise or mutilation, a consciousness of this eventual, and indeed speedy reproduction, induces them violently to rid themselves of the injured member, and to await in seclusion the formation of a complete substitute for it. Some species which are unprovided by nature with any shelly covering, uniformly have recourse to such shells as they find best accommodated to their purpose, and in which their bodies are immersed, while their claws are protruded and unprotected. The correspondence of parts in both sides of almost all other animals is far from being universably observable in these. The clas pers on one side are often of extraordinary size, and on the other slender and small; and in some instances the large arm is obliged to be supported by the back of the animal, both while walking and at rest, from its unwieldy and extravagant size. The genus comprehends an immense variety of species; but the chief division is into the Brachyouri and the Macrouri, or the shorttailed and the long-tailed: under the former of which the crab commonly used in this country for food is the principal. It is found chiefly on the rocky coasts. Among the Macrouri, the common lobster is the principal, and a well-known specimen. It inhabits in the clearest water, and at the base of rocks which project over the sea. It is extremely prolific, depositing about 12,000 eggs each time of laying. The warmth of summer is required for maturing them. The C. Norwegicus, or Norwegian crab, is naturally of a pale red colour, and variegated with yellow. It is longer, and more slender than the ordinary lobster. For a representation of it see Entomology, Plate II. fig. 1. C. grapsus, or the streaked crab, is an inhabitant of the American and Indian seas. Its -general pale yellow is finely interspersed with red streaks and spots. For a specimen see Entomology, Plate II. fig. 2. CANCROMA, the boat-bill, in natural history, a genus of birds of the order Grallæ. Generic character: bill gibbous, shaped like an inverted boat; nostrils placed in a furrow, and small; tongue small, and toes divided. Of these there seems to be only one species, though Gmelin speaks, somewhat doubtfully indeed, of a second. The C. cochlearia, or crested boat-bill, is principally found in places near the water. It is a native of South America, particularly abounding in the northern parts of it. Perching on trees which overhang the brooks and rivers, it darts down on the fish swimming underneath, which constitute its chief food. It is supposed, but not ascertained, that it feeds also upon crabs. CANDLE, a small taper of tallow, wax, or spermaceti; the wick of which is commonly of several threads of cotton, spun and twisted together. There are two sorts of tallow-candles; the one dipped, the other moulded: the former are the common candles. Tallow candles should be made of equal parts of bullock's and sheep's fat. The cot ton made use of in the manufacture of candles comes from Turkey. This is first wound into rather a fine thread, which is cut into proper lengths, and five, six, or more united, so as to make it of a fit size for the candle required. The machine for cutting the cotton is a smooth board fastened on the knees, and the upper surface is the blade of a razor, aad a round piece of cane, placed at a certain distance from one another, according to the length of the cotton wanted. The cotton is carried round the cane, and being brought to the razor, is instantly separated from the balls. The cotton is then made smooth by pulling, and spread at equal distances, on rods about half an inch in diameter, called broaches. The tallow is melted, and after it is well skimmed, it is brought to the mould, in which the cottons are dipped. The workman holds three of these broaches between his fingers, and immerses the cottons into the melted tallow; these he afterwards hangs up till they become cold and hard, during which others are dipped. When cold they are dipped a second and a third time, and so on till the candles are of the proper size. During the operation the tallow is kept to a proper temperature by means of a small charcoal fire. An invention of modern date has taken off much of the labour of the tallow-chandler: this consists of a beam with fixed pullies, round which ropes are made to pass, and on one end of the ropes can be suspended six or more broaches, the weight of which is balanced by weights in an opposing scale, and which may be increased, as the candles become larger. The workman by this means has only to guide the candles and not to support them between his fingers. Mould candles are so called from their being run or cast in moulds made of pewter. In these the cotton is introduced by means of a wire, and kept in a perpendicular position, till the tallow is poured in, and when cold the candles are easily drawn out. Wax candles are made of a cotton or flaxen wick, slightly twisted, and covered with white or yellow wax. Of these, there are several kinds; some of a conical figure, used to illumine churches, and in processions, funeral ceremonies, &c. Others of a cylindrical form, used on ordinary occasions. The first are either made with a ladle or the hand to make wax candles with the ladle. The wicks being prepared, a dozen of them are tied by the neck, at equal distances, round an iron circle, suspended directly over a large bason of copper tinned, and full of melted wax: a large ladle full of this wax is poured gently on the tops of the wicks one after another, and this operation continued till the candle arrive at its destined bigness, with this precaution, that the three first ladles be poured on at the top of the wick; the fourth at the height of; the fifth at ; and the sixth at ; in order to give the candle its pyramidal form. Then the candles are taken down, kept warm, and rolled and smoothed upon a walnut-tree table, with a long square instrument of box, smooth at the bottom. As to the manner of making wax-candles by the hand, they begin to soften the wax, by working it several times in hot water, contained in a narrow, but deep caldron. A piece of the wax is then taken out, and disposed, by little and little, around the wick, which is hung on a hook in the wall, by the extremity opposite to the neck; so that they begin with the big end, diminishing still as they descend towards the neck. In other respects, the method is nearly the same as in the former case. However it must be observed, that in the former case, water is always used to moisten the several instruments, to prevent the wax from sticking; and in the latter, oil of olives, or lard, for the hands, &c. The cylindrical wax-candles are either made, as the former, with a ladle, or drawn. Waxcandles drawn, are so called, because actually drawn in the manner of wire, by means of two large rollers of wood, turned by a handle, which turning backwards and forwards several times, pass the wick through melted wax contained in a brass ba→ son, and at the same time through the holes |