83 
When these oils are subjected to fractional distillation no 
product of constant boiling-point is obtained, the oils requiring 
for this purpose a preliminary purification with concentrated 
nitric acid. 
The greatest portion of the oils remains unattached, and 
the acid solution contains nitrobenzol (from which aniline was 
prepared), nitrotoluol and binitrotoluol, and small quantities of 
fatty acids produced from traces of olefines which are pro- 
bably contained in the crude oils. 
I tried to separate these olefines by adding bromine to the 
crude oil until the colour of the latter no longer disappeared; 
a few drops, however, are sufficient for a large quantity of 
the oil, and when the whole is subjected to distillation, a very 
few drops of bromine compounds of a high boiling point 
remained behind, the quantity of which was too small for 
further examination. 
The oil after this treatment was well washed, dried over 
potash, and rectified repeatedly over sodium. By fractional 
distillation, the following four hydrides were obtained, and 
.found to be identical with the hydrides from thecannel tar: — 
C 10 H 12 hydride of amyl, boiling point 34° C. 
C 12 H u hydride of hexyl, 68° C. 
C u H 16 hydride of heptyl, 98° C. 
Ci 6 His hydride of octyl, 119° C. 
In addition to these I obtained a small quantity (about one 
gramme) of a liquid boiling between 20° — 30° C, and hence 
we may infer that also hydride of butyl is present in small 
quantities. 
I stated in the paper above alluded to that hydride of 
amyl boils at 39° C. The same compound from petroleum 
boils at 34° C. I find, however, that the presence of traces 
of foreign substances alter the boiling point of this body very 
considerably. Thus, for instance, I obtained from the crude 
oil about one ounce of a liquid which boiled from 15° — 20° C; 
