254 Transactions.—Chemistry. 
respect from most rock oils, and is especially free from all traces of sulphuretted 
hydrogen gas. 
Minute flakes of a white substance float in the oil, and are gradually 
deposited when it is allowed to remain quiet at a low temperature, nearly the 
whole of this solid substance becoming dissolved when the oil is gently heated. 
The temperature at which the oil boils is 340? Fah., and it does not appear 
to evaporate at ordinary temperature, for when exposed to the air it remains 
unchanged, neither thickening nor acquiring a skin on the surface. 
Its temperature requires to be raised to 260? Fah. before its vapour inflames. 
This oil differs from petroleum oils generally in not containing paraffin. 
In this respect it resembles a so-called surface oil occurring in Santa Barbara 
County, California. These oils also agree in being of very similar density. 
Details of the results of the distillation of a small quantity of this oil have 
been given in a special report by Dr. Hector, but since then I have had the 
opportunity given me of operating upon larger samples, and I have thus 
obtained further results which could not well be observed otherwise. 
A large quantity of the oil was distilled very slowly until 82 per cent. of 
volume of the charge had passed over. The residual matter left in the retort 
set very hard on cooling to 60° Fah. It had the appearance of pitch, and 
would have yielded a further quantity of solid and liquid distillates if needed. 
The density of the several portions of the oil obtained was as follows :— 
No VoLUME OF DISTILLATE SPECIFIC 
UPON CHARGE, GRAVITY. 
1 2 per cent. T T :880 
2 DO- y MES "E .888 
3 BB. yj 900 
4 4 » :910 
5 8 j ‘917 
6 8 ү :926 
7 12 5 "9838 
8 12 5 :030 
9 13 j :898 
10 4 33 ‘908 
11 NU :938 
82 
The total amount of oil distilled over was therefore 82 per cent. upon the 
charge taken, and the amount of residual matter left, 18 per cent. This was 
a kind of pitch, intensely black, and solidifying to a very hard mass at common 
temperatures. By destructive distillation it would, of course, yield further 
oily and solid products. 
On an examination of the columns just given, it will be observed that the 
produets of the distillation of this oil do not constantly increase in density as 
the process of distillation goes on, but that, while they increase in density with 
