Part 91
=Powder of Mudar.= (_Pulvis Calotropis._) Take of the roots of mudar, collected in the months of April and May from sandy soils, a sufficiency; carefully remove, by washing, all particles of sand and dirt, and dry in the open air, without exposure to the sun, until the milky juice contained in it becomes so far inspissated that it ceases to flow on incisions being made in it. The bark is then to be carefully removed, dried, and reduced to powder. Preserve in well-corked bottles.--_Dose._ As an alterative tonic, 3 grains, gradually increased to 10 grains or more, thrice daily. As an emetic, from 1/2 to 1 drachm.
=CAL'OTYPE.= See PHOTOGRAPHY.
=CALUM'BA.= _Syn._ CALUMBÆ RADIX, B. P. CALUM'BA-ROOT; KALUMB, Hind. The root of a plant of Eastern Africa, extensively used in _medicine_ as a stomachic and mild tonic. _Dose_, 10 to 20 grains, three or four times a day. The botanical name of this plant is _Jateorhiza palmata_, or _Cocculus palmatus_. See CALUMBINE (_below_); also INFUSIONS and TINCTURES.
=CALUM'BA WOOD.= This wood, which is used as a tonic by the Cingalese, is not the produce of the true calumba plant, but of _Menispermum fenestratum_. It contains the alkaloid BERBERINE (which _see_).
=CALUM'BINE.= _Syn._ CALOM'BINE, _Calum'bina_. A bitter substance discovered by Wittstock in calumba root.
_Prep._ 1. Digest calumba root (in coarse powder) in water acidulated with acetic acid; express, filter, boil to one half, again filter, add carbonate of calcium, in slight excess, and evaporate to dryness in a water bath; reduce the residuum to powder, and digest it in boiling alcohol; the latter will deposit crystals of CALUMBINE on cooling.
2. (Wittstock.) Evaporate tincture of calumba root (made with rectified spirit) to dryness; dissolve the residuum in water, and agitate the solution with an equal bulk of ether; after repose for a short time, decant the ethereal portion, distil off most of the ether, and set the liquid aside to crystallise.
_Prop., &c._ Impure calumbine occurs as a yellow-brown mass; when pure, it forms rhombic prismatic crystals or delicate white needles; it is only slightly soluble in alcohol, ether, and water; 40 parts of boiling rectified spirit take up only 1 part of calumbine. Its best solvent is acetic acid; it is also soluble in acidulated and alkalised water. Neither nut-galls nor metallic salts affect its solution. Concentrated sulphuric acid dissolves it, and assumes first a yellow, and then a red colour. Its properties indicate that weak vinegar or sour wine would be the best menstruum for extracting the medicinal virtues of calumba root. _Dose_, 1 to 3 gr. twice a day as a tonic and stomachic, in dyspepsia, debilitated stomach, bilious vomiting, &c.; and in the later periods of dysentery and diarrh[oe]a.
=CALX.= This term was formerly applied to the residuum of the combustion of any substance; or to any substance which had been exposed to a strong heat. See CALCINATION, LIME, &c.
=CAMBOGE'.= See GAMBOGE.
=CAM'ERA LU'CIDA.= [L. and Eng.] When a ray of light (_r_) falls upon a quadrangular glass prism (_a_), it is bent by two reflections (at _c_ and _d_), and thrown upwards where it may be received by the eye, to which it will appear described on the table or sheet of paper (_f_) placed to receive it. The point of a pencil used to trace any object on the paper can also be seen, and by its means the picture can be easily copied. When the prism is mounted on a stand, and a thin brass plate with a small hole through it for the eyepiece adjusted thereto, it forms the CAMERA LUCIDA of the opticians. The image may be magnified or lessened by placing a lens so as either to intercept the rays before they strike the prism, or before they reach the eye. An ingenious person will readily be able to set up this instrument, than which a more useful one cannot exist.
=CAM'ERA OBSCU''RA.= [L. and Eng.] An optical instrument for producing upon a screen the image of a field of view more or less extensive. It was invented by Baptista Porta in the 16th century. The principles and construction of the camera obscura may be thus described:--A convex lens (_B_) is placed in a hole admitting the light into a darkened box or chamber (_A_), which, falling on a white ground (_D_), produces an inverted picture of every object within its range. The image thus formed may be restored to its natural position, by allowing the rays of light to pass through two lenses instead of one, or by receiving the rays on a mirror placed at an angle of 45°, when the image will be thrown on the floor in its original position. The picture may be viewed through an oblong aperture cut in the box, or the experiment may be performed in a darkened room, by placing the lens in a hole in the shutter, and allowing the image to fall on the wall, or on a sheet of white paper stretched to receive it.
In the simplest form, when intended for taking views or portraits, the image is thrown upon a mirror placed at an angle of 45°, and resting on the bottom of the box, by which means it is thrown upwards against a plate of glass, also placed at a similar angle. On this is laid a piece of semi-transparent tracing paper, on which the object is distinctly seen painted, and may be traced out with a pencil. When the camera is used in photography, slides are provided to retain the sensitive paper in the proper position in the box or dark chamber to receive the image, and the whole apparatus is adjusted with screws, and slides of the most delicate description. Achromatic glasses are also employed. See PHOTOGRAPHY.
=CAM'PHINE.= The name given by the trade to rectified oil of turpentine when sold for burning in lamps, in order that purchasers may not be aware of the inflammable character of the liquid. Since the introduction of the hydro-carbon oils from coal, shale, and petroleum, camphine has been little used for burning. To rectify the turpentine, it is passed in vapour through a solution of caustic potash, soda, or lime; or through sulphuric acid.
=CAM'PHOR.= C_{10}H_{16}O. _Syn._ CAM'PHIRE, LAU'REL CAM'PHOR; CAMPHO'RA, B. P. A crystalline substance found in many plants; though only obtained in large quantities from two, namely, _Camphora officinarum_ and _Dryobalanops aromatica_. The first, commonly known as the laurel camphor tree of China and Japan, yields the camphor of commerce; the latter, the Sumatra or Borneo camphor, and the peculiar fluid known as liquid camphor.
It is found that several of the essential oils, by carefully distilling off about one third their volume, yield a species of camphor. By collecting this, and redistilling the remainder of the oil 2 or 3 times, a farther quantity of camphor may be obtained. Oil of rosemary, treated in this way, yields about 10% of camphor; oil of sweet marjoram the same; oil of sage yields 13%; oil of lavender, 25%. By keeping the oils loosely corked, and in a cool place, they produce a larger portion of this camphor. Aniseed camphor is the congealable portion of oil of aniseed, separated from the liquid oil, which it resembles in odour and flavour.
=Camphor, Am'ber.= See PYRETINE (Crystallised).
=Camphor, Com'mercial (Crude).= The produce of the laurel camphor tree, brought to Europe chiefly from China and the island of Formosa, in the form of greyish grains, aggregated into crumbling cakes.--_Prep._ The Chinese and Japanese extract the camphor by cutting the wood into small pieces, and boiling it with water in iron vessels, which are covered with large earthen capitals or domes, lined with rice straw. As the water boils, the camphor is volatilised along with the steam, and condenses on the straw.
=Cam'phor, Commercial (Refined).= _Syn._ WHITE CAMPHOR; CAMPHO'RA, B. P. _Prep._ 100 parts of crude camphor are mixed with 2 parts each of quick-lime and animal charcoal, both in powder, and the mixture is placed in a thin, globular, glass vessel, sunk in a sand bath. The heat is then cautiously applied, and the vessel gradually and carefully raised out of the sand as the sublimation goes on. When the process is complete, the subliming vessel is removed and allowed to cool.
_Obs._ The whole process of refining camphor requires great care and experience to ensure its success. If conducted too slowly, or at a heat under 375° Fahr., the product is found to be flaky, and consequently unsaleable, without remelting or subliming. An improvement on the common method is simply to sublime the above mixture in any convenient vessel furnished with a large and well-cooled receiver, and to remelt the product in close vessels under pressure, and to cool the liquid mass as rapidly as possible.
_Prop., &c._ A white, semi-crystalline solid, very volatile at common temperatures; freely soluble in alcohol, ether, bisulphuret of carbon, benzol, oils, and acetic acid, and sufficiently so in water (about 1-1/4 gr. to 1 oz.), to impart its characteristic smell and taste; 100 parts of alcohol (sp. gr. ·806) dissolve 120 parts of camphor; concentrated acetic acid dissolves twice its weight of camphor; average sp. gr. ·990. It fuses at 347°, boils at 400° Fahr., and when set fire to, burns with a bright flame. It evaporates slowly at ordinary temperatures, and crystallises on the inside of bottles. While floating on water it undergoes a curious rotatory movement.
_Uses, &c._ Camphor is sedative, narcotic, anodyne, diaphoretic, and anaphrodisiac. _Dose_, 2 to 10 gr. in the form of pill or bolus, or made into an emulsion with yolk of egg, mucilage, or almonds. In overdoses it is poisonous. The best antidote is opium or wine, preceded by an emetic. It is also used externally in ointments, liniments, and embrocations.
Camphor is frequently put into wardrobes and clothes-trunks, to keep away insects; it is used to make the white stars and fire of the pyrotechnist; and by the varnish-maker to increase the solubility of copal and other gums. Mixed with six times its weight of clay, and distilled, it suffers decomposition, and yields a yellow, aromatic, volatile oil, smelling strongly of thyme and rosemary, which is much used by the wholesale druggists and perfumers to adulterate some of the more costly essential oils, and by the fancy soap-makers to scent their soaps.
Camphor may be beaten in a mortar for some time, without being reduced to powder, but if it be first broken with the pestle, and then sprinkled with a few drops of rectified spirit of wine, it may be readily pulverised. By adding water to an alcoholic or ethereal solution of camphor, this drug is precipitated under the form of an impalpable powder of exquisite whiteness.
_Tests._ Pure camphor is entirely soluble in rectified spirit, oils, and strong acetic acid; a fragment placed on a heated spoon or in a warm situation will wholly disappear, and the evolved fumes will be highly fragrant (camphoraceous), and be free from an acid or terebinthinate odour. In an alcoholic solution of natural camphor ammonia gives but a slight precipitate, which is dissolved on shaking the mixture; a similar solution of artificial camphor under the like treatment gives a flocculent precipitate, which remains undissolved. See CAMPHOR, FACTITIOUS (_below_).
=Camphor, Facti''tious.= _Syn._ HYDROCHLORATE OF TUR'PENTINE, HYDROCHLORATE OF CAMPHENE, ARTIFICIAL CAMPHOR. Prepared by passing dry hydrochloric acid gas into pure oil of turpentine, cooled by a freezing mixture or pounded ice. After a time a white, crystalline mass is formed, which must be drained, and dried by pressure between folds of bibulous paper. It may be purified by solution in alcohol.
_Prop., &c._ It has a camphoraceous taste and odour; burns with a greenish, sooty flame, and when blown out evolves a terebinthinate odour; heated a little above the boiling-point of water, slight fumes of hydrochloric acid gas are perceptible.
=Camphor, Hydrochlo''rate of.= _Syn._ MU''RIATE OF CAMPHOR; CAMPHO'RÆ HYDROCHLO''RAS, L. By passing hydrochloric acid gas over camphor, in small fragments, until it ceases to be absorbed.
=Camphor, Liq'uid.= _Syn._ CAMPHOR OIL; O'LEUM CAMPHO'RÆ, L. A pale yellowish, limpid fluid, which exudes from _Dryobalanops aromatica_, a tree growing in Sumatra and Borneo, when deep incisions are made in the trunk. It is supposed that the crystalline SUMATRA CAMPHOR (see _below_) is deposited from this fluid. The liquid camphor has somewhat the odour of CAJEPUT OIL, and might, no doubt, be beneficially employed for the same purpose. It is sometimes imported into Europe.
=Camphor, Monobromated.= C_{10}H_{15}O_{1}Br. Coarsely powdered camphor is introduced into a flask of about ten times the capacity of the amount it is intended to prepare. A fine stream of bromine is then allowed to fall upon the powder with continual agitation; the addition of bromine ceases when the camphor is liquefied. A large long abductor tube is then fitted to the flask, and the other end plunged into an alkaline solution, which will absorb the vapour that would otherwise incommode the operator. The flask is placed in a water bath that is raised to ebullition, when the reaction soon commences. This is at first rather active, there being an abundant evolution of hydrobromic gas, and some vapour of bromine and undecomposed camphor. The liquid, which is at first dark brown in colour, acquires an amber colour and the evolution of gas suddenly slackens. The operation should be carried out at a temperature between 80° and 90° C. The amber-coloured liquid that remains in the flask solidifies upon cooling, and appears then as a slightly citrine-coloured friable mass. It is purified by treating it several times with boiling 90° to 95° alcohol, filtering the liquor, and leaving it to crystallise. The crystals are to be dried in the air upon unsized paper.
Dr Bourneville advises monobromated camphor to be administered either in the form of pills, made up with conserve of roses, or of a mixture rubbed up with mucilage of gum arabic and syrup. He gives it in doses varying from twelve to thirty centigrams daily. Where it cannot be taken by the mouth he injects the following solution subcutaneously:--Monobromated camphor 3 gr., alcohol 35 gr., glycerin 22 gr.
=Camphor, Nitrate of.= _Syn._ CAMPHOR OIL; O'LEUM CAMPHO'RÆ FACTI''TIUM, L. Prepared by dissolving camphor in nitric acid, in the cold.
=Camphor, Sul'phite of.= From camphor and sulphurous acid gas, as hydrochlorate of camphor.
=Camphor, Suma'tra.= _Syn._ BOR'NEO CAMPHOR, HARD C., DRAGON'S BRAIN PERFUME. Obtained from _Dryobalanops aromatica_, being found in natural fissures or crevices of the wood. It resembles ordinary camphor in most properties, but its odour is not of so diffusible a nature. This kind is not seen in European commerce.
=CAMPHOR CAKES.= See BALLS (Camphor).
=CAMPHOR'IC ACID.= H_{2}C_{10}H_{14}O_{4}. _Syn._ ACIDUM CAMPHOR'ICUM, L. _Prep._ From camphor, 1 part; and nitric acid (sp. gr. 1·33), 4 parts; distilled together in a glass retort, with a gradually increasing heat, until vapours cease to be evolved; the camphor that has volatilised is then added to that in the retort, along with 4 or 5 parts more of nitric acid, and the process repeated again and again, until 20 parts of acid have been consumed, when crude camphoric acid crystallises out of the remaining liquor on cooling. The crystals are purified by washing with cold distilled water, solution in boiling water, and evaporating the solution until a pellicle forms; crystals of pure camphoric acid are formed as the liquid cools.
_Prop., &c._ Small, colourless, lamellar or acicular crystals; acid; bitter; fusible at 158° Fahr.; sparingly soluble in water; soluble in alcohol; alcoholic solution not precipitated by water, which distinguishes camphoric acid from benzoic acid. Its salts are called CAMPHORATES. The soluble camphorates may be made by digesting the carbonate or hydrate of the metal in a hot solution of the acid, and the insoluble camphorates by double decomposition. By distillation, camphoric acid yields a colourless, crystalline, neutral substance, which has been improperly called anhydrous camphoric acid.
=CAM'WOOD.= This dye-stuff resembles Brazil wood in its properties, and is used in a similar manner.
=CAN'ADA BALSAM.= _Syn._ BAL'SAMUM CANADEN'SE, TEREBINTH'INA CANADEN'SIS, L. A thick, viscid oleo-resin obtained from the _Abies balsamea_ (Lindley), a tree of common growth in Canada and the State of Maine. It is much employed as a medium for mounting microscopic objects. When pure it is perfectly transparent, has an agreeable odour (not terebinthinate), and is wholly soluble in rectified oil of turpentine, with which it forms a beautiful glassy and colourless varnish, much used for preparing a semi-transparent copying paper.
A mixture of 3 parts of Canada balsam and one of wax, if added to pile masses, is said to have the effect of binding together the component parts of the mass, and of keeping the piles made from it soft and in good shape.
=Canada Balsam, Facti''tious.= _Syn._ BALSAMUM CANADENSE FACTI''TIUM, L. _Prep._ 1. Yellow resin, 3 lbs.; oil of turpentine, 1 gall.; dissolve, and add essence of lemon, 2 dr.; oil of rosemary, 1-1/4 dr.
2. To the last add of nut oil, 1 pint. Both are sold in the shops for Canada balsam.
=CAN'DIES.= See CANDYING.
=CAN'DLES.= Candle-making, once a rude and noisome trade, has, since the researches of Chevreul and Branconnot into the nature of the fats, developed into one of the most important branches of scientific industry, the progressive improvements in which, accompanied by a corresponding cheapening and immensely increased efficiency in one of our chief means of artificial illumination, have added greatly to the comfort and enjoyment of every civilised community. Candles are either dipped, moulded, or rolled. The cheaper sorts of tallow candles are formed by the first process, and wax candles by the last; all the other kinds are moulded. The moulds are tubes of pewter, well polished on the inside, eight or more being fitted into a frame, the upper part of which forms a trough to receive the melted candle material. When in the moulds the candles are inverted; in other words, the bottom of each mould corresponds to the top of the candle. The wick passes through a small hole at the lower extremity of the tube, and is held in the axis by a little bar placed across the top. At the factories of Price's Patent Candle Company the frames of moulds are ranged close together in long benches, and are filled with hot candle material from cars running along little railways above them. When quite cold the candles are withdrawn. The plan of pulling them out one by one with the aid of a bodkin has been superseded at the factories above mentioned, by the ingenious device of blowing them out with compressed air.
The wicks of ordinary tallow candles are made of the rovings of Turkey skein-cotton, 4 or more of which, according to the intended thickness of the wick, are wound on a reel, from which they are again run off, and cut into the proper lengths. Of late years the wicks of the best candles have been made in such a way that they do not require snuffing. This object is effected by causing the wick to bend over, and its end to fall outside the flame, where it is exposed to the oxygen of the air. This bending over is variously brought about.--1. By twisting the wick with one strand shorter than the rest, which, being slightly stretched during the moulding of the candle, contracts again and bends the wick when the fat melts. 2. By plaiting the cotton into a flat wick, which naturally takes the required curve. Such a wick is generally dipped in a solution of borax, which preserves it from being acted upon by the flame except at its extreme point at the edge of the flame. A very fine wire is sometimes included in the plaited wick. 3. In Palmer's patent two-wicked candles, which were formerly much used in lamps, the wicks are saturated with subnitrate of bismuth ground up with oil; they are then twisted tightly round a wire, which is withdrawn after the candle is moulded. In burning, the ends gradually untwist and stand out of the flame on either side. Other devices are said to be employed.
The wicks of candles should be free from knots and inequalities, as well as from adhering particles of cotton, the presence of all of which are the cause of the "guttering" one frequently sees in a burning candle. The finer the thread of which the wick is composed the more complete will be the combustion of the melted fatty material. Unless the above precautions are attended to, in selecting the wick, it will not be so entirely consumed as it ought to be.
=Candles, Com'posite.= Mould candles formed of a mixture of the hard fatty acid obtained from palm oil and the stearine of cocoa-nut oil. They were introduced in 1840. Other compositions are occasionally used, such as a mixture of spermaceti and hard white tallow, to which a little bleached resin is added.
=Candles, Med'icated.= These have been proposed as a convenient means of diffusing the active principles of certain volatile substances through the atmosphere, and for complete and partial fumigations. They are seldom employed in England.
=Candles, Mercu''rial.= From the red sulphide or the grey oxide of mercury mixed with wax, and a wick of cotton inserted therein. Recommended by Mr Colles for partial mercurial fumigation. They are burnt under a glass funnel with a curved neck, the upper orifice of which is directed to the diseased part.
=Candles, Par'affin.= From the beautiful translucent substance paraffin (which _see_). These candles surpass all others in elegance, and are entirely free from odour and greasiness. The light produced by 98 lbs. of paraffin candles is equal to that of 120 lbs. of spermaceti, or 138 lbs. of wax, or 144 lbs. of stearic, or 155 lbs. of the best composite candles (Letheby). They are sometimes delicately tinted with red, mauve, violet, crimson, and rose colour. Aniline colours will not dissolve in paraffin. Stearic acid, however, is a solvent for them, and accordingly when the candles are tinted with the coal-tar colours these are previously dissolved in the stearic acid, always mixed with the paraffin. This insolubility of the aniline colours in paraffin has been suggested as a test for the purity of this hydrocarbon, and of its freedom from stearic or other fatty acids. For colouring paraffin candles black the paraffin is heated nearly to the boiling point with anacardium shells or nuts, which dissolve readily in the heated paraffin. The Belmontine Candles of Price's Patent Candle Company are formed of the paraffin of Rangoon tar.