506 Eev. J. Barlow, [March 26, 



WEEKLY EVENING MEETING, 

 Friday, March 2<3. 



SiK Benjamin Collins Brodie, Bart. D.C.L. F.R.S. Vice- 

 President, in the Chair. 



Rev. John Barlow, M.A. F.R.S. Vice-Pres. & Sec. R.I. 



On Mineral Candles and other Products manufactured at 

 Belmont and Sherwood, 



The candles and the other products (liquid hydro-carbons), on 

 which Mr. Barlow discoursed, are manufactured by Price's Candle 

 Company, at Belmont and Sherwood, according to processes 

 patented jjy Mr. Warren De la Rue. The novelty of these sub- 

 stances consists — 1. In the material from which they are obtained. 

 2. In the method by which they are elaborated. 3. In their 

 chemical constitution. 



1. The raw material is a semifluid naphtha, drawn up from wells 

 sunk in the neighbourhood of the river Irrawaddy, in the Burmese 

 empire. The geological characteristics of the locality are sand- 

 stone 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 as a medicine. Being in part volatile, at common tem- 

 peratures, this naphtha is imported in hermetically-closed metallic 

 tanks, to prevent the loss of any constituent. Reichenbach, 

 Christison, Gregory, Reece,* Young,f 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 Rue, is, from first to last, 

 a simple separation, without chemical change. 



2. The processes adopted. — In the commercial processes, as 

 carried out by Mr. George Wilson, at the Sherwood and Belmont 

 Works, the crude naphtha is first distilled with steam at a tem- 

 perature of 212^^ Fahr. ; 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 diffus- 

 able, however different may be their boiling points. In practice, 



♦ See Proceedings of the Royal Institution, Vol. I., p. 4. f Ibid, p. 135, 



