286

CAMBOGE-CAMBRIC-CAMEL-CAMLET-CAMPHOR.

CAMLET, or CAMBLET, a plain stuff, of which there are several varieties. Some are made of goats'hair; in others, the warp is of hair, and the woof half hair and half silk; others, again, are entirely of wool; and in some, the warp is of wool and the woof of thread. There are striped, watered and figured camlets.

entitled, “Traité théorique et pratique de l'Impression | A ship drawing 15 feet water could by this means des Tissus," 4 vols. Svo. Paris. 1846, with a quarto be made to draw only 11 feet; and the largest manatlas of plates. The work itself contains 165 wood of-war in the Dutch service could be made to pass engravings and 429 actual specimens of printed the sand-banks of the Zuyder Zee. The length of calico in its various stages and styles, neatly pasted one of these camels was 127 feet; the breadth at one in among the type, producing a very pleasing effect. end 22 feet, and the other 13 feet: the hollow part These specimens were furnished to the author by was divided into several compartments. some of the principal calico-printers of Alsace, Switzerland, Normandy, the environs of Paris, England, and Scotland. Each house sent a sufficient quantity of print for the whole impression of the work, accompanied by a written description of the process adopted for producing each specimen. This highly useful method of illustration was first adopted in 1835, by Dr. Thomas Thomson, who published in the "Records of General Science," a valuable series of papers on this Art. It has also been adopted by Mr. Parnell in his Treatise on Calico-Printing, contained in his excellent work on "Chemistry applied to Manufactures," 8vo. London. 1843. CALOMEL, the protochloride of mercury. [See limes, and condenses upon the straw. In China, the MERCURY.]

CAMPHINE. [See TURPENTINE.]

CAMPHOR is the produce of the Laurus camphora, or camphor laurel, of Japan and China. The roots and wood of the tree are chopped up, and boiled with water in an iron vessel, to which an earthen head containing straw is adapted; and the camphor sub

chopped branches are boiled in water till the camphor begins to adhere to the stirrer: the liquor is then strained, and the camphor concretes on standing: it is afterwards mixed with a finely powdered earth, and sublimed from one metallic vessel into another. Two kinds of unrefined or crude camphor are known in

tub-camphor, from the circumstance of its being brought from Batavia (and reported to be the produce of Japan) in tubs, covered by matting, each surrounded by a second tub, secured on the outside by hoops of twisted Each tub contains from 1 cwt. to 14 cwt., or

cane.

CALORIMETER. [See HEAT-THERMOMETER.] CAMBOGE or GAMBOGE, a gum resin, forming a well-known yellow water-colour. The best gamboge is from Siam and the kingdom of Camboja, (whence its name,) and is said to be the produce of Garcinia Cochinchinensis, the broken leaves and branch-commerce: 1. Dutch or Japan camphor, also called lets of which form a yellow milky juice, which is run into bamboos, so as to form cylindrical sticks. Another kind, which is suffered to harden in masses, which are covered with leaves, is said to be derived from Cambogia gutta. Dr. Wight, however, states that the tears of cambogia gutta are a substance altogether distinct from true gamboge. The best gamboge is brittle and inodorous, of conchoidal fracture, orangecoloured, or reddish yellow, smooth, and somewhat glistening. Its powder is bright yellow. It may be resolved into resin and gum by the successive action of ether and water. The finest gamboge contains about 70 per cent. of resin, sometimes termed gam-taining from 14 to 14 cwt. It is chiefly produced in bodic acid, which forms numerous salts. Gamboge is used as a pigment, and in miniature-painting; also to tinge gold varnish. In medicine it is used as a drastic purge. It is sometimes improperly used by confectioners to colour liqueurs. An artificial gamboge, of very little value, is manufactured with turmeric and other materials.

CAMBRIC, a species of very fine white linen, first made at Cambray, in French Flanders, whence the name.

CAMEL, a machine invented in Holland, about 1688, for raising ships by the buoyant power of water. It consists of two similar hollow water-tight vessels, so constructed that they can be applied on each side of the hull of a ship. On the deck of each vessel windlasses are attached, which work the ropes passed under the keel of the vessel to be raised. When the camel is employed to raise a ship, the water is allowed to fill each half of it; and when the ship is firmly attached to the camel, the water is pumped out, and the buoyancy of the hollow vessels raises up the ship.

more. It consists of pinkish grains, which by their mutual adhesion form lumps. It is of larger grain, clearer, and sublimes at a lower temperature than the second variety, which is known in commerce as ordinary crude camphor, China camphor, and Formosa camphor. This is imported from Singapore, Bombay, &c., in square chests, lined with lead foil, and con

the island of Formosa, and is conveyed in junks to Canton, whence the foreign markets are supplied. It consists of dirty greyish grains. It varies in quality, but is sometimes as fine as the Dutch kind.

C

Crude camphor very much resembles moist sugar before it is cleaned. It is refined, and converted into the beautiful well-known article sold in the shops, by sublimation. This process is carried on in spheroidal vessels, called bomboloes (Fig. 418). They are made of thin flint glass, and weigh about 1 lb. each, and measure about 12 inches across. Each vessel has a short neck. When filled with crude camphor, they are imbedded in a sand-bath, and Fig. 418. heated to a temperature of from 250° to 280°, which is afterwards raised to between 300° and 400°. About 2 per cent of quick-lime, and 2 parts bone-black, in fine powder, are added to the melted camphor, and the heat raised,

so as to boil the liquid. The vapour condenses in | sometimes for several hours together; but if, while the upper part of the vessel. As the sublimation the camphor is rotating, the surface of the water be proceeds, the height of the sand around the vessel is touched with any greasy substance, (a glass rod dipped diminished. The process is completed in about 48 in turpentine answers best,) all the floating particles hours. This operation requires considerable attention quickly dart back, and are instantly deprived of all and experience. Dr. Ure says:-" If the temperature motion.' The motions of the camphor are accelerated be raised too slowly, the neck of the bottle might be by placing the glass in vacuo. Camphor fuses at filled with camphor, before the heat had acquired the 347°, and boils at 400°, when it may be distilled proper subliming pitch; and if too quickly, the whole without decomposition. The density of camphorcontents might be exploded. If the operation be vapour is 5.27. Camphor is sparingly soluble in carried on languidly, and the heat of the upper part water; 1 part of camphor requiring about 1,000 parts of the bottle be somewhat under the melting point of of water for solution. This aqueous solution is named camphor, that is to say, a little under 350°, the con- camphor julep. It is very soluble in alcohol, ether, densed camphor would be snowy, and not sufficiently acetic acid, sulphuret of carbon, and some other subcompact and transparent to be saleable. Occasionally, stances. 100 parts of spirits of wine (specific gravity sudden alternations of temperature cause little jets 0.806) dissolve 120 of camphor, forming the camphorto be thrown up out of the liquid camphor at the ated spirit of the Pharmacopoeia. On adding water bottom upon the cake formed above, which soil it, to this, nearly all the camphor is thrown down, in a and render its re-sublimation necessary." minutely divided state. Considerable use is made of camphor in medicine, both as an internal and an external remedy; but it ought never to be taken internally without medical advice. A dose of two scruples appears to be sufficient to cause death.

The vessels being removed from the sand-bath, the mouth is closed with tow, and in this hot state, water is sprinkled over them, and they crack. When quite cold, the cake of camphor, weighing about 11 lbs., is removed, and trimmed, by paring and scraping into the form of large hemispherical cakes, perforated in the middle. In this process the lime retains the impurities and a portion of the camphor: the latter is recovered by heating the mixture in an iron pot, with a head to it, and the product is refined by a second sublimation.

In a large chemical factory near Birmingham, which the Editor was allowed to visit, the camphor-refining room contained about a dozen sand-baths, standing parallel to each other across the room, each containing about ten bomboloes. The temperature of the room was about 150°, very dry, and highly charged with vapour of camphor. This being inflammable, means are taken to obtain heat and light, without the introduction of fire into the room. Accordingly, the sandbaths are heated from baths of fusible metal, kept at the proper temperature by a furnace outside; and, to diminish the escape of the camphor vapour, each bombolo was covered with a glass shade. Another use of this shade was stated to be, to exclude the air, which, if admitted, would cause the sublimed camphor to be opaque instead of clear. It was also stated that the essential oil is driven off from the crude camphor, before subliming.

Camphoric acid (C10 H7 O3 + HO) is obtained by the action of nitric acid upon camphor.

CAMWOOD, a red dye-wood, obtained from the vicinity of Sierra Leone. Its colouring matter differs but little from that of Nicaragua wood.

CANAL. [See NAVIGATION, INLAND.]

CANDLE, a cylinder or slightly conical rod formed of solid fat, in the axis of which a bundle of parallel, twisted or woven fibres is enclosed.

It is necessary to the due comprehension of some of the details of candle-making to enter briefly into the chemistry of fats and oils, substances of firstrate importance to the welfare of a country, the large proportion of carbon contained in them rendering them valuable sources of food and artificial light. Most fats and fixed oils, vegetable and animal, are mixtures of two, and generally three distinct compounds, each of which taken singly has all the properties of fats. The first of these substances, called stearine, (from σréap, tallow or suet,) is solid at common temperatures; it constitutes the solid fatty ingredient in mutton-tallow; the second is oleine, (from λatov, oleum, oil,) and is liquid at ordinary temperatures, and down to the temperature of freezing

pápуapov, a pearl,) on account of its mother-of-pearl lustre it is solid at ordinary temperatures. All fats may therefore be regarded as mixtures of the fluid oleine with the solid stearine or margarine. If the solid be in larger proportion than the fluid, as in various kinds of tallow, it requires a greater degree of heat to melt it. If the fluid portion prevails, as in the oils, the melting point is lowered.

Camphor (C10 H, O) is a white and semi-trans-water; the third substance is named margarine, (from parent solid, (sp. gr. 0.987,) of a crystalline fracture, a peculiarly fragrant odour, and a warm, pungent, and somewhat bitterish taste, accompanied by a sense of coldness on the tongue. It is soft and tough, but can be readily pulverised if moistened with a few drops of spirits of wine. It evaporates in the air at ordinary temperatures, and gradually sublimes in close vessels, and attaches itself to the surfaces most exposed to the light. If a vessel exhausted of air, and containing a piece of camphor, be exposed to the direct rays of the sun, these crystals will be formed phor upon the surface of water," in which the opinions of many speedily. When small pieces of perfectly clean camphor are allowed to fall upon the surface of pure water, they rotate and move about with great rapidity,

(1) In the year 1837, the Editor contributed a paper to the "Magazine of Popular Science" on "The rotatory motion of cam

eminent philosophers on this subject are brought together. Raspings of cork, steeped in sulphuric ether, sublimated benzoic acid,

potassium, and some other substances, also rotate and move about on the surface of water.

Larger pans are required than those used t England to do the same amount of work; but the operations are performed more quickly. From li of fatty matter 85 lbs. of tallow are produced by th method, whilst the more dangerous one now practised gives only 82 lbs., so that the manufacturer gen three per cent. more tallow by the above process. which amply repays him for the 5 lbs. of sera which are in a great measure lost. But the a matters remaining in the pan can be used as ma or, by mixing them with saw-dust, as fuel. T would bear the same relation to glycerine as ether does to alcohol. method renders tallow-melting safe, and gets rai f

(1) The oxide of glyceryl, at the moment of its liberation, unites with water. This acid has not been insulated. If it were so, it

that most disagreeable odour which characterises the | between each dipping for the tallow to consolidate ; neighbourhood of tallow-melting establishments.

The wicks used for the best candles are cotton rovings imported from Turkey. Four or more skeins, according to the thickness of the wick, are wound off at one time into bottoms or clues, and afterwards cut to the proper lengths, being first doubled and twisted so as to leave a loop at one end. Wicks for dip candles are also cut very expeditiously by machinery. Balls of cotton previously made into a loose roving or cord, consisting of a dozen or more threads each, and differing in thickness according to the size of the candles, are put into a box or drawer. The ends are then attached to a rod or broach, and equal lengths of cotton are cut off by drawing a knife along a whole range of them at once, a slight twist being given to the whole of them by the action of the machine. When the wicks are cut to the proper length they are dipped into melted tallow and rubbed between the palms of the hands; and on being left to harden they are arranged upon smooth sticks or broaches about half an inch in diameter and three feet long, for the purpose of dipping. The dipping-room contains a boiler for melting the tallow, a dippingmould or cistern, and a large wheel for supporting the broaches. A long balance-shaped beam is suspended from the ceiling, to one end of which is attached a wooden frame for holding the broaches with the wicks properly arranged. The opposite end of the beam has a scale-pan with weights to counterbalance the wooden frame, and to enable the workman to determine the size of the candles. The end of the lever which supports the frame is situated just above the dipping-cistern, so that by gently pressing down the balanced beam, the wicks descend into the melted tallow, Fig. 419, which is kept in a

hence the dipping-room requires to be kept cool; for which purpose the business of candle-making is confined to the cooler months of the year; but if carried on in summer, the cooler part of the night is the time preferred.

Dr. Ure describes a machine for dipping candles, which has long been used at Edinburgh. For the details of this machine we must refer to his Dictionary, article CANDLE. It consists essentially of a strong upright post, turning upon pivots, and supporting a wheel with 12 horizontal arms, from the end of each of which is a frame or post containing 6 rods, on each of which are 18 wicks, making altogether 1,296 wicks. On turning the wheel round, each post is brought in succession over the dipping-mould, and the wicks receive a fresh coating. The constant motion through the air tends to consolidate the tallow, and it is stated that in moderately cold weather, a wheel of common-sized candles can be finished in two hours.

The moulds used in making mould candles are of pewter, and consist of two parts; namely, a hollow cylinder of the length of the candle open at both ends, and nicely polished on the inside; and a small metallic conical cap with a hole in the centre for the wick. Glass moulds have also been lately introduced. 8 or 12 of these moulds are fixed in a wooden frame, the upper part of which is a trough, into which the open extremities of the moulds are inserted on a level with its surface, so that the tops of the moulds point downwards. In order to insert the wicks the frame is placed on its side, and the man introduces a hooked wire into the mould, and passing it out through the point at the top attaches to it the loop of a wick, a number of which he holds in his left hand; he then draws back the wire, and brings the wick along with it. All the moulds being thus provided, another man passes a small wire through the loop of each wick, for the purpose of keeping it stretched in the centre, or along the axis of the cylinder. The moulds are filled by running tallow into the trough from a boiler kept at the proper temperature, and furnished with a cock or tap. When the moulds are almost half filled the supply of tallow is cut off, and the workman laying hold of the portion of each wick that projects from the point pulls it tight. This prevents the wick from curling, and secures it in its proper position. The filling is then completed, and the frame put aside to cool. The candles ought to remain in the moulds until the next day, but it is known when they are properly set by a snapping noise produced by pressing the thumb against the bottom of the moulds. When this occurs the wires are pulled out, the superfluous tallow is scraped off with a small wooden spade; a bodkin is introduced into the loop of the wicks, and the candles are withdrawn in succession. They are then removed to the storehouse, where in the course of a few months they become sufficiently white for sale. No duty is now paid on candles.

The tallow used in moulding is sometimes melted over a solution of alum, the sulphuric acid of which

U

appears to act as a purifier. The proper consistence | bottom that may support the pith: but this, like for moulding is judged of by the appearance of a scum other feats, soon becomes familiar even to children; on the surface, which forms in hot weather between and we have seen an old woman, stone blind, per111° and 119° Fahr.; in mild weather at 108°, and forming this business with great despatch, and seldom in cold at about 104°. failing to strip them with the nicest regularity. When these junci are thus far prepared, they must lie out on the grass to be bleached and take the dew for some nights, and afterwards be dried in the sun.

"Some address is required in dipping these rushes in the scalding fat or grease; but this knack also is to be attained by practice. The careful wife of an industrious Hampshire labourer obtains all her fat for nothing; for she saves the scummings of her baconpot for this use: and if the grease abounds with salt, she causes the salt to precipitate to the bottom, by setting the scummings in a warm oven. Where hogs are not much in use, and especially by the seaside, the coarser animal oils will come very chey, A pound of common grease may be procured for four-pence; and about 6lbs. of grease will dip a

Wax is not adapted for moulding, in consequence of the contraction which it undergoes in cooling, and the tenacity with which it adheres to the sides of the moulds. Wax candles are made in the following manner :-A set of wicks properly cut and twisted, and warmed at a stove, are attached to a ring of wood or metal, and suspended over a basin of melted wax, which is taken up by a large ladle and poured on the tops of the wicks, each wick being kept constantly twisted round its axis by the fingers; the wax in running down adheres to the wicks, and completely covers them. This process is repeated at intervals until a sufficient thickness is attained. The candles are then rolled while hot with a flat surface of box-wood upon a smooth table of walnut-wood kept constantly wet; this makes them truly cylin-pound of rushes; and one pound of rushes may be drical. This basting, twisting of the wicks and rolling is sometimes repeated two or three times before the candles are finished, but a skilful workman will cover the wicks with the proper quantity of wax without taking them down. If a wax candle be broken across, the annular layers, like the yearly rings in wood, can be easily counted, and their number indicates the number of times the wax has been poured over the wick.

The large wax candles used in Roman Catholic churches are made by placing a wick upon a slab of wax, bending this together and then rolling it.

The long, thin, coiled wax tapers are made in the following manner :-the wick, which must be uniform, is wound round a drum, from which it is passed into the wax pan, at the bottom of which is fixed a guiding roller, and from thence through a drawing plate to a second drum. The drawing plate is of metal, and is similar to that used in wire-drawing the holes in it correspond in size to the diameter of the taper, and the wick is passed through smaller and smaller holes until it is of the proper thickness.

Rush-lights are made in the same manner as dip candles. The Rev. Gilbert White, in his "Natural History of Selborne," describes the method of making them by the cottagers of Hampshire. He says:-"The proper species of rush for this purpose seems to be the juncus effusus, or common soft rush, which is to be found in most moist pastures, by the sides of streams and under hedges. These rushes are in best condition in the height of summer; but may be gathered, so as to serve the purpose well, quite on to autumn. It would be needless to add, that the largest and longest are best. Decayed labourers, women, and children, make it their business to procure and prepare them. As soon as they are cut they must be flung into water, and kept there; for otherwise they will dry and shrink, and the pcel will not run. At first a person would find it no easy matter to divest a rush of its peel or rind, so as to leave one regular, narrow, even rib from top to

bought for one shilling; so that a pound of rushes, medicated and ready for use, will cost three shillings. If men that keep bees will mix a little wax with the grease, it will give it a consistency and render it more cleanly, and make the rushes burn longer: mutton suet would have the same effect. A good rush, which measured in length 2 feet 4 inches, being minuted, burnt only 3 minutes short of a hour. These rushes give a good clear light. Watch lights (coated with tallow) it is true shed a disal one, darkness visible;' but then the wicks of these have two ribs of the rind or peel to support the pih, while the wick of the dipped rush has but one. The two ribs are intended to impede the progress of the flame and make the candle last.

"In a pound of dry rushes, avoirdupois, which I caused to be weighed and numbered, we found upwards of 1,600 individuals. Now suppose e of these burns, one with another, only half an hour, then a poor man will purchase 800 hours of lizt, a time exceeding 33 entire days, for three shillin According to this account, each rush before dip costs d of a farthing, and th afterwards. T a poor family will enjoy 5 hours of comforts. light for a farthing. An experienced old housekeeper assures me that 1lb. of rushes completely supes his family the year round, since working people no candle in the long days, because they rise and to bed by day-light. Little farmers use rushes t in the short days, both morning and evening, in t dairy and kitchen; but the very poor, who are always the worst economists, and therefore must contin very poor, buy a halfpenny candle every eve which in their blowing open rooms does not b much more than 2 hours. Thus have they 2 hours' light for their money, instead of 11.”1

(1) It will be remembered that these observations were wr in the year 1775. Since that time tallow has become murt, et.. and the trade of candle-making has risen to the di "mity of a “w facture, which, together with the repeal of the duty on ca has had the effect of considerably lowering the price.