Transactions of the Royal Society, 349 



tion of the liquid which is deposited during the compression of 

 oil-gas, as practised by the portable oil-gas company. 



It is a thin, light fluid ; sometimes transparent and colourless, 

 at others opalescent, being yellow or brown by transmitted, and 

 green by reflected light. It has the odour of oil-gas. When the 

 bottle containing it is opened, evaporation takes place from the 

 surface of the liquid ; and it may be seen by the striae in the air 

 that vapour is passing off from it. Sometimes in such circum- 

 stances it will boil, if the bottle and its contents have had their 

 temperature raised a few degrees. After a short time this abun- 

 dant evolution of vapour ceases, and the remaining portion is 

 comparatively fixed. 



The specific gravity of this substance is 0.821. It does not 

 solidify at a temperature of 0° F. It is insoluble, or nearly so, in 

 water; very soluble in alcohol, ether, and volatile and fixed oils. 

 It is neutral to test colours. It is not more soluble in alkaline 

 solutions than in water; and only a small portion is acted upon 

 by them. Muriatic acid has no action upon it. Nitric acid 

 gradually acts upon it, producing nitrous acid, nitric oxide 

 gas, carbonic, and sometimes hydrocyanic acid, fyc, but the ac- 

 tion is not violent. Sulphuric acid acts upon it in a peculiar 

 manner. 



This fluid is a mixture of various bodies, which may, by their 

 difference of volatility, be separated in part from each other. 

 Some of it drawn from the condenser, after the pressure had been 

 repeatedly raised to 30 atmospheres, and at a time when it was at 

 28 atmospheres, then introduced rapidly into a stoppered bottle 

 and closed up, was, when brought home, put into a flask and dis- 

 tilled, its temperature being raised by the hand. The vapour 

 which came off, and which caused the appearance of boiling, was 

 passed through a glass tube at 0°, and then conducted to the 

 mercurial trough ; but little uncondensed vapour came over, not 

 more than thrice the bulk of the liquid ; a portion of fluid col- 

 lected in the cold tube, which boiled and evaporated when the 

 temperature was allowed to rise ; and the great bulk of the liquid 

 which remained might now be raised to a comparatively high point, 

 before it entered into ebullition. 



A thermometer being introduced into another portion of the 

 fluid, heat was applied, so as to keep the temperature just at the 

 boiling point. When the vessel containing it was opened, it 

 began to boil at 00° F. As the more volatile portions were 

 dissipated, the temperature rose : before a tenth part had been 

 thrown off, the temperature was above 100°. The heat con- 

 tinued gradually to rise, and before the substance was all vo- 

 latilized, it had attained 250°. 



With the hope of separating some distinct substances from this 

 evident mixture, a quantity of it was distilled, and the vapours 



Vol. XX. 2 B 



