THE TECHNOLOGIST. [Dec. 1, 1864. 



zUO ON CHEMISTRY APPLIED TO TEE ARTS. 



the greatest improvements in the manufacture of these candles is that 

 carried out by Price's Candle Company ; but before describing to you 

 this beautiful process, as adopted by Mr. G. F. "Wilson, at this company's 

 works, allow me to state a few facts. Up to 1840 the best kind of 

 candles were those made of spermaceti, or of animal fatty matters, which 

 were cold and hot pressed. In that year Mr. "Wilson, whilst experi- 

 menting with the view of making candles which would not require 

 snuffing for the illumination on the occasion of Her Majesty's marriage, 

 discovered that a combination of cocoa-nut stearine with stearic acid 

 would make candles giving a beautiful light, and free from the necessity 

 of snuffing. These he called "composite," and they were soon largely 

 sold. In 1838 Mr. Fremy published his interesting discoveries, showing 

 that when oils or fatty matters were mixed with 20 or 30 per cent, of 

 concentrated sulphuric acid, the fatty matters were split, or, as he calls 

 it, saponified, and that sulpho-margaric, sulpho-stearic, sulpho-oleic, and 

 sulpho-glyceric acids were formed. He further observed that boiling 

 water decomposed the sulpho-stearic and margaric acids, and only par- 

 tially the sulpho-oleic, into stearic, margaric, oleic, and sulphuric acids, 

 which last acid remains in the water together with the sulpho-glyceric 

 acid and that portion of the sulpho-oleic acid not decomposed, the other 

 acids remaining insoluble and floating on the surface. In 1842 Messrs. 

 G. Price and Jones secured a patent to carry out on a practical scale the 

 scientific discoveries of Mr. Fremy. In that patent tw r o or three im- 

 portant facts are brought out ; first, that if instead of operating at a 

 low temperature, as recommended by Fremy, heat was employed, the 

 action of the sulphuric acid on the organic compounds would give rise 

 to sulphurous acid, which they discovered had the remarkable property 

 of converting the liquid oleic acid into a solid acid called " elaidic," 

 thus largely increasing the yield of solid fatty acids. Their mode of 

 operating was this — 10 or 12 per cent, of concentrated sulphuric acid 

 was added to the fai.ty matters which had been previously liquified by 

 heat, and the whole was kept at a temperature of 200° for 24 hours. 

 During that time the fatty matters were split into their primitive ele- 

 ments, and the oleic acid was converted into elaidic acid. The whole 

 was then repeatedly treated with boiling water, to dissolve the sulpho- 

 glyceric acid and other impurities, leaving the solid fats ready for 

 distillation. Mr. G. F. Wilson has since then greatly improved this 

 part of his manufacture, as the beautiful candles, everywhere to be seen, 

 will amply prove. The most important improvement in a chemical 

 point of view is the following : — He has found, for example, that fatty 

 matters are split up into their component parts, by decreasing quantities 

 of vitriol, as the temperature used is increased. Thus, at a temperature 

 of 200°, 15 parts of vitriol are required ; at 350°, 6 parts ; at 500°, 1 

 part. Further, by employing this small proportion of sulphuric acid, 

 not only is the expense of washing the fatty matters after their saponi- 

 fication by the acid avoided, but the distillation may be proceeded with 



