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 When quite cold the candles are withdrawn. The plan of pulling them out one by one with the aid of a bodkin has been superseded at the factories above mentioned, by the ingenious device of blowing them out with compressed air.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.