“Gide. -vacuum He 100°, of ‘the alone Se oils: — Raw 
~ Rumania, ‘Balachana, Alaska and eae Vege 
| hydrocarbons could be isolated. 
“hence neither the cepa hemiterpene isoprene, she caliphate ¢ 
Vitealed ith 05: tort ec. pinene Sie digoih ene. This erect aude to a - tenpen 
of 0.05 to 0.1 percent. From this added terpene 0.6 or 1 s g. mercury | m1 
be obtained, according to amount of terpene added, “so ‘that the; limit } 
‘ 
7 Or this method lies near 0.008 per cent. — veer 
As B. J. Brooks!) remarks in a 2 ete that. the difficulties of Soblainine the | 
aliphatic hydrocarbons in a state of purity are very great. A good bibliography 
is wanting. Work-has been done in this pepe in Roeper: but it. has only: 
partially known. At og ae 
Although petroleum probably contains all normal parattin rydrocarbons: ip 
CysHes, and perhaps beyond, it has been impossible up to now to obtain pure cor 
pounds from this raw material; syntheses also of such higher hydrocarbons have not 
yet succeeded. Young. had to fractional- distil a mixture: of tie Kia pies L 
ee 
alleged i have eee isolated from petroleum : and obtained | pure, "then the 
were all wrong. : Sette 
Mes, In many text books on organic chemistry a series of tynieal reactions ge _methai 
and its homologues is given. These reactions are mostly valid for the lowe me embe 
of the series; but not for the higher. — The Grignard reaction is not ap lic: ible f 
alkylhalides with more than six carbon atoms. Bromohexane give. practical ; on 
_ dodecane, and hence reacts as follows: CsHisMgBr ++ CeHisBr = vi 
-.. Many known reactions fail with the higher paraffins on. account of - ! 
_ the alkylhalides. For which reason, the condensation of higher alky 
carbons by means of metallic. sodium occurs more. easily than 
s X 
a) Chiem. and See eneere 22 (1920), 933, : 
sag 
