132 Mr. Schorlemmer on a New Series of Hydrocarbons [May 3^ 



pounds. Pure amyl-compounds from fusel-oil were also prepared with the 

 greatest care, and their specific gravities and boiling-points compared, 

 under exactly the same circumstances, with the compounds prepared from 

 petroleum. The results of this investigation are contained in the follow- 

 ing Table.:— 



Amyl-Comjpounds. 

 From fusel' oil. From petroleum. 



Boiling-point. Specific gravity. Boiling-point. Specific gravity. 



CgH,,Cl 101° C. 0-8750 at 20° 

 c'h }^ 140° C* 0-8733 at 15° 

 an'o 132° C. 0-8148 at 14° 



34° C. 0-6263 at 17° 



101° C. 0-8777 at 20° 



140° C. 0-8752 at 15° 



132° C. 0-8199 at 14°. 



It appears from this Table that the boiKng-points of the same com- 

 pounds agree perfectly, and that the specific gravities show only very small 

 differences, those of the substances obtained from petroleum being a little 

 higher. This is easily accounted for by an admixture of higher boiling 

 compounds, which towards the end of the distillation raise the boiling- 

 points a little, and which cannot be removed completely, even by long- 

 continued rectifications. The amyl-compounds from petroleum and those 

 from fusel-oil are therefore identical. 



III. " On a New Series of Hydrocarbons derived from Coal-tar .^^ 

 By C. Schorlemmer. Communicated by Professor Roscoe. 

 Eeceived April 26, 1866. 

 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 un- 

 acted upon volatilize first, and a black tarry liquid, equal in bulk to 

 about half the crude oil, remains behind f . 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 con- 

 tinued 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 (S^n^2n-^2y the following analyses and deter- 

 minations of the vapour-densities show : — 



* The boiling-point of acetate of amyl is given very differently by different observers 

 (Cahours found 125°, Landolt 133-134° ; Pogg. Ann. vol. cxxii. p. 554). My ob- 

 servation agrees perfectly with that of Wanklyn (Chem. Soc, Journ. (2.) iii. p. 30). 



t Journ. Chem. See. vol.'xv. p. 420. 



