94 



UNDULATOUY FORCES. LIGHT. 



[FATTY MATTERS. 



hatnl, in consequence of tlieir sticking so tight to the 

 ides of the mould, that they cannot be drawn out of it. 

 The operation for wax candles is conducted as follows : 

 The wicks are first wanned in a stove, and then sus- 

 pended to a hoop over the vessel of melted wax. The 

 Utter is then poured f mm a ladle over each wick in suc- 

 cession ; and to prevent the wax from accumulating more 

 on one side of the wick than the other, the wick is 

 sharply rotated between the finger and thumb. \\1ien 

 the candles are thus coated to about one-third their pro- 

 per size, they arc allowed to cool for a short time, and 

 the operation is then repeated until they are half-made. 

 This being accomplished, they are removed from the 

 hoop, and rolled between two marble slabs until they are 

 of one uniform thickness. The upper end of each candle 

 is now formed by cutting it down to a metal tag, which 

 coven one end of the wick. The candles are then again 

 suspended to the hoops, but in a reversed position ; and 

 the operations of basting and rolling are repeated as often 

 as necessary. Finally, the lower ends of the candles are 

 cut square, so as to make them of the desired length. 



The large wax candles used in churches are formed by 

 rolling the wick in a thin layer of wax, and then, after 

 adding layer after layer, it is finished off in the way just 

 described. 



Long wax tapers are made by winding the wick on a 

 drum, and then leading it, by means of a guide-roller, into 

 a trough of melted wax, from which it passes through a 

 series of holes progressively smaller and smaller, on to a 

 second drum, where it is wound up the operation being 

 somewhat like that of wire-drawing. A little turpentine 

 is added to the wax to render it pliable, so that it may 

 not crack as it bends over the drum. 



We proceed now to speak of the different kinds of fats, 

 and of the candles made from them. 



Tallow is obtained from animals ; it is the fat which is 

 located under the skin, about the intestines, in the bones 

 and muscles, and around the kidneys. It is extracted 

 by cutting the tissue into small pieces, then submitting 

 it to heat, and finally to pressure. The tallow or fat of 

 bones and the dressings of skins is obtained by boiling 

 them in a large caldron, and skimming off the fat as it 

 rises to the surface. A large quantity of tallow is ob- 

 tained from meat during the ordinary operations of cook- 

 ing ; and this is known in commerce by the name of 

 kitchen-stuff. Tallow, when first obtained, has a very 

 disagreeable smell ; indeed, it contains a great number 

 of impurities, as blood, animal tissue, water, &c. ; and 

 in this condition it is not suited for the manufacture of 

 candles. To render it pure, it is submitted to various 

 operations, which are called rendering. One of these is 

 as follows : The tallow is melted in a large copper set 

 upon an open fire, and the water contained in the impure 

 fat is boiled away ; during this stage of the operation the 

 animal tissues and bloody matters coagulate and rise to 

 the surface. These are strained off and pressed, the 

 residue is sold under the name of greaves or cracklings, 

 and is used for feeding dogs. Another mode of render- 

 ing, ia to submit the melted tallow to the action of steam, 

 which is blown into it from a pipe pierced with a number 

 of holes. But the most effective process of all is that 

 recommended by M. D'Arcet: the tallow is molted by 

 team-heat, and then treated with very dilnto sulphuric 

 acid ; this destroys the colouring matter, and separates 

 the animal tissue in the form of black flakes, which 

 speedily settle to the bottom of the vessel. After drawing 

 off the tallow, and washing it well with warm water, it is 

 allowed to stand until it rises to the surface and is cold. 

 In this state it is nearly five from colour and smell. 

 Some years ago Mr. Watt obtained a patent for purify- 

 ing tallow by a mixture of acids, as sulphuric, oxalic, 

 nitric, and chromic ; the two latter of which give out 

 oxv.'cn gat, and thus bleach the fat. 



Tallow consists of several fats ; one of which (olcine) 

 is liquid at ordinary temperatures ; and the others (mar- 

 garine and stearine) are solid. Occasionally, also, when 

 it has been obtained from particular animals, it contains 

 a few other fats, as hircino, butyrine, <tc. The relative 

 proportions of those fats give to tallow its different con- 



sistence; for example, beef-marrow, or bone-fat, which 



is r.ithcr hanl, contains 7C of stearine to 24 of oluine; 



mutton fat, 62 to 38 ; beef fat, 54 to 46 ; butter, 40 to (50 ; 



hog's-lard, 38 to 62 ; goose fat, 32 to 68 ; .and turkey 



fat, 26 to 14. Again, the melting-point of different 



tallows varies with the proportions of these constituents ; 



! for, while common tallow melts at from 94 to 104 Fah. , 



' marrow fat requires a temperature of 115 to liquefy it, 



and hog's-lard is fluid at 81. 



Three sorts of candles are made out of ordinary tallow ; 

 namely, rushlights, dips, and moulds. The former are 

 not much employed in towns, except for watch-lights ; 

 but they are still the favourite candle with the poor in 

 country villages ; and it is very probable that they are 

 chosen because of their not guttering so much as the 

 common dip when they are exposed to currents of air : 

 besides which, they burn longer, and are, therefore, more 

 economical. In many cases these candles are made by 

 the peasants themselves. Mr. Gilbert White has given 

 an account, in his Xiiiurnl History of SeUtourne, of the 

 manner in which they are produced by the cottagers of 

 Hampshire. They take a quantity of rushes, whirii h;ivo 

 been previously peeled, and dip them into the melted 

 tallow, so that six pounds of tallow shall serve for 1,600 

 rushes. In this way they produce caudles which require 

 228 to make a pound. The rushes are peeled on three 

 sides for the best lights, and on two only for watch-lights, 

 and which, says Mr. Gilbert White, only shed a dismal 

 light darkness visible. Of the other kind, a good oae, 

 which measured 2 feet 4J inches in length, burned 

 57 minutes ; and he was assured by an experienced old 

 housekeeper, that l^lb. of rushes, after having been 

 coated with tallow, completely supplied her family for a 

 year. The cost of lighting with rushes he estimated at 

 one farthing for 5J hours ; whilst a halfpenny candle, in 

 the blowing, open rooms of the poorer classes, only lasted 

 two hours. The rushlights that are sold in London 

 vary from ten to eighteen in the pound. A specimen of 

 ten to the pound, which measured 11 5 inches in length, 

 burnt at the rate of lj inches in the hour, equal to a 

 consumption of 74 grains ; and it took five of them to 

 give the light of one sperm of 120 grains per hour. 



Ordinary dips burn with great irregularity even the 

 same candle will vary from 120 to 180 grains per hour ; 

 and, when consumed at the standard rate, they give a 

 light which is just one-third that of sperm. Dips are 

 made of all sizes, from six to sixteen in the pound ; and 

 they are sold at from 5d. , and upwards, per pound, 

 according to the price of tallow. 



Mould candles, of tallow, are generally made of the 

 better description of fat ; they are, therefore, whiter than 

 dips, and melt at a little higher temperature. A mould 

 candle, of six to the pound, burns at the rate of about 

 143 grains per hour, and its illuminating power is rather 

 more than half that of a sperm of 120 grains ; so that, 

 weight for weight, its power is about half that of sperm. 



The disadvantages attending the use of tallow candles 

 are, that they melt at a very low temperature, and are, 

 therefore, not suited for warm climates or hot rooms ; 

 they gutter when they are exposed to draughts ; they 

 require constant snuffing ; they give out an unpleasant 

 smell, both before burning and after; they soil the 

 hands, and grease everything with which they come into 

 contact ; and, in warm weather, they are very apt to 

 break. Some of these disadvantages have been overcome 

 by the chandlers of Dublin, many of whom have acquired 

 a high reputation for the superior quality of their mould 

 candles ; and it has been found, that by waxing the wicks 

 before they are used for making the candles, the disposi- 

 tion to gutter, which is so objectionable, is in a great 

 degree prevented. Candles of this description generally 

 fetch from a halfpenny to three-farthings a pound more 

 than the commoner sort. 



Palm oil is the produce of the Elais Guiniensis, or 

 Atirira elais, a palm that grows very abundantly in the 

 tropical parts of Africa, Most of the palm oil that we 

 ve into this country comes from the western coasts 

 of that continent chiefly from Guinea. It is obtained 

 by crushing the fruit, then submitting it to the heat of. 



