686 CANDLE 



consists : 1. In the material from which they are obtained. 2. In the method by 

 which they are elaborated. 3. In their chemical constitution. 



The raw material is a semifluid naphtha, drawn up from wells sunk in the neigh- 

 bourhood of the river Irrawaddy, in the Burmese Empire. The geological charac- 

 teristics of the locality are sandstone and blue clay. In its raw condition the substance 

 is used by the natives as a lamp-fuel, as a preservative of timber against insects, and 

 ns a medicine. Being in part volatile at common temperatures, this naphtha is im- 

 ported in hermetically-closed metallic tanks, to prevent the loss of any constituent. 

 Reichenbach, Christison, Gregory, Reece, Young, Wiesman (of Bonn), and others 

 have obtained from peat, coal, and other organic minerals, solids and liquids bearing 

 some physical resemblance to those procured from the Burmese naphtha ; but the 

 first-named products have, in every instance, been formed by the decomposition of the 

 raw material. The process of De La Hue, is, from first to last, a simple separation, 

 without chemical change. 



In the commercial processes, as carried out at the Sherwood and Belmont Works, 

 the crude naphtha is first distilled with steam at a temperature of 212 F. ; about 

 one-fourth is separated by this operation. The distillate consists of a mixture of 

 many volatile hydro-carbons ; and it is extremely difficult to separate them from each 

 other on account of their vapours being mutually very diffusible, however different 

 may be their boiling points. In practice, recourse is had to a second or third distil- 

 lation, the products of which are classified according to their boiling points or their 

 specific gravities, which range from 0'627 to 0'860, the lightest coming over first. It is 

 worthy of notice, that though all these volatile liquids were distilled from the original 

 material with steam of the temperature of boiling water, their boiling points range 

 from 80 F. to upwards of 400 F. 



These liquids arc all colourless, and do not solidify at any temperature, however 

 low, to which they have been exposed. They are useful for many purposes. All are 

 solvents of caoutchouc. The vapour of the more volatile, Dr. Snow has found to be 

 highly anaesthetic. Those which are of lower specific gravity are called in commerce 

 Sherwoodole and Belmontine ; these have great detergent power, readily removing oily 

 stains fron silk, without impairing even delicate colours. The distillate of the higher 

 specific gravity is proposed to be used as lamp-fuel ; it burns with a brilliant white 

 flame ; and, as it cannot be ignited without a wick, even when heated to the tempera- 

 ture of boiling water, it is safe for domestic use. 



A small percentage of hydro-carbons, of the benzole series, comes over with the 

 distillates in this first operation. Messrs. De La Eue and Miiller have shown that it 

 may be advantageously eliminated by nitric acid. The resulting substances, nitro- 

 benzole, &c., are commercially valuable in perfumery, &c. 



After steam of 212 F. has been used in the distillation just described, there is left a 

 residue, amounting to about three-fourths of the original material. It is fused and 

 purified from extraneous ingredients (which Warren De La Eue and H. Miiller have 

 found to consist partly of the colophene series) by sulphuric acid. The foreign 

 substances are thus thrown down as a black precipitate, from which the supernatant 

 liquor is decanted. The black precipitate, when freed from acid by copious washing, 

 has all the characteristic properties of native asphaltum. The fluid is then transferred 

 to a still, and, by means of a current of steam made to pass through heated iron tubes, 

 is distilled to any required temperature. The distillates obtained by this process are 

 classed according to their distilling points, ranging from 300 to 600 F. The 

 distillations obtained, at 420 F. and upwards, contain a solid substance, resembling 

 in colour and in many physical and chemical properties, the paraffineof Eeichenbach ; 

 like it, it is electric, and its chemical affinity is very feeble ; but there are reasons for 

 believing that a difference exists in the atomic constitution of the two substances. 

 The commercial name of Belmontine is given to one of the fluids from the Burmese 

 pitch. Candles manufactured from the solid material (Paraffine) possess great illu- 

 minating power. It is stated that such a candle weighing th lb., will give as much 

 light as a candle weighing th lb. made of spermaceti or stearic acid. Its property of 

 fusing at a very low temperature into a transparent liquid, and not decomposing 

 below 600 F., recommends this substance as the material of a bath for chemical 

 purposes. As to the fluids obtained in the second distillation, already described, they 

 all possess great lubricating properties ; and, unlike the common fixed oils, not being 

 decomposable into an acid, they do not corrode the metals, especially the alloys of 

 copper, which are used as bearings of machinery. This aversion to chemical combi- 

 nation, which characterises all these substances, affords, not only a security against 

 the brass-work of lamps being injured by the hydro-carbon burnt in them, but also 

 renders these hydro-carbons the best detergents of common oil lamps. It is an 

 interesting physical fact, that some of the non-volatile liquid hydro-carbons possess the 

 fluorescent property which Stokes has found to reside in certain vegetable infusions. 



