468 Mr. Schorlemmer on the Hydrocarbons [Nov. 16, 



Heptyl compounds derived from 



C. M. Warren has lately published * an investigation on the hydro- 

 carbons contained in the American petroleum, which he isolated according 

 to a new method of fractional condensation. He states that the petro- 

 leum contains two series of the hydrocarbons C m H 2n+2 , the isomeric pairs 

 of which show a difference in their boiling-points of 7-8. 



Some of the results which I have formerly obtained tend to confirm 

 this view. 



Frankland, Wurtz, Pelouze, and Cahours found 30 as the boiling-point 

 of hydride of amyl ; the hydrocarbons of the same composition, which I 

 isolated from the light oils obtained from Cannel coal, boils constantly 

 between 39 and 40. The hydride of heptyl obtained from the same 

 source boiled at 98-99, and the same hydrocarbon I found in American 

 petroleum, whilst Pelouze and Cahours give 92-94 as the boiling-point ; 

 and in my last communication I have quoted some experiments made by 

 Mr. Wright, who found that from that part of American petroleum which 

 boils between 95-100 a considerable quantity of a hydrocarbon, C 7 H 16 , 

 may be obtained which boils constantly at 90-92. These latter hydro- 

 carbons and their derivatives show, even after repeated rectification, higher 

 specific gravities than the isomeric alcohol -radicals and the hydrocarbons 

 from azelaic acid. 



Thus it appears that bodies showing a purely physical isomerism are as 

 numerous in the marsh-gas family as in the case of the terpines, C 10 H 16 . 



In order to complete this investigation, I intended to study in the same 

 manner the hydrocarbons C B H u , namely hydride of hexyl from suberic 

 acid, methyl-amyl, and, if possible, ethyl-butyl ; but this intention could 

 not be carried out, as I could not succeed in preparing methyl-amyl. This 

 hydrocarbon appears not to be formed by any of the methods which are 

 employed to prepare the so-called mixed alcohol-radicals. A mixture of 

 the iodides of methyl and amyl is exceedingly slowly attacked by sodium. 

 The boiling-point of the mixture is below the fusing-point of sodium, and 

 the metal soon becomes coated with a hard crust of iodide of sodium. I 

 * Mem. American Academy, New Series, vol. ix. p. 156. 



