III. On a new series of hydrocarbons derived from coal-tar

• Published in: Proceedings of the Royal Society of London
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1867
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1098/rspl.1866.0032; https://royalsocietypublishing.org/doi/pdf/10.1098/rspl.1866.0032

The light oils obtained by the destructive distillation of Cannel-coal at a low temperature, contain, besides the hydrocarbons of the marsh-gas and benzol series, other substances, which are attacked by concentrated sulphuric acid. If the oil, which has been repeatedly shaken with this acid, be subjected to distillation, the hydrocarbons which are unacted upon volatilize first, and a black tarry liquid, equal in bulk to about half the crude oil, remains behind. On heating this residue more strongly, a brown oil, having an unpleasant smell, comes over at about 200°C. the temperature rises gradually up to 300°C., and at last a black pitchy mass is left in the retort. Even after repeated rectifications the oil always leaves a solid black residue behind, and it was only by continued fractional distillations over solid caustic potash and metallic sodium, that I succeeded in isolating substances possessing nearly a constant boiling-point and volatilizing almost completely. The compounds which I thus obtained from Cannel-coal oil, boiling below 120°C., are hydrocarbons of the general formula (C n H 2 n -2 ) 2 , as the following analyses and determinations of the vapour-densities show:— (1) C 12 H 20 boiling-point 210°C. ( a ) 0·262 substance gave 0·840 carbonic acid and 0·290 water. ( b ) 0·1978 substance gave 0·635 carbonic acid and 0·2195 water.