the Petroleum of Rangoon. 121 
paper, and immediately subjected to strong pressure between 
folds of blotting paper. The yellow colouring matter, which all re- 
mained in solution in the ether after it cooled, was thus, ina great 
measure, imbibed by the paper; and the crystalline matter was 
procured in a state of purity by repeating this process twice. 
’ On first procuring this crystalline substance, I considered it 
as the same with the naphthaline procured not long ago from coal- 
tar by Mr Kipp, as related in his paper in the Philosophical 
Transactions for 1821. This opinion I was led to form from the 
appearance of the crystals, the nature of the substance which 
yields them, and the process of distillation by which they were 
procured. 
On a careful examination, however, I find that the crystal- 
line principle of petroleum differs materally from that of coal-tar, 
as well as from every other known body ; and I shall therefore 
beg leave to denominate it Petroline, according to the analogy 
suggested by the name of Mr Krpp’s crystalline principle. 
As procured by the process described above, petroline forms 
foliaceous masses of small crystals of snowy whiteness, and bright 
pearly lustre. It is somewhat unctuous, and has a naphthous 
odour, which becomes very faint on exposure for some time to 
the air, and is removed altogether by boiling in alcohol. It 
fuses at 135° into a transparent, limpid, colourless fluid; but 
softens ten degrees lower. From a state of fusion it concretes 
on cooling into a translucent brittle mass, like wax, the density 
of which is 909 at 60° Fahr. At a temperature intermediate 
between the boiling point of water and a low red heat, the fluid 
boils, and distillation takes place. The greater part of the petro- 
line condenses in the form of a fluid, which becomes on cooling 
a translucent waxy mass, with its original properties. But owing 
to the elevated temperature required for its distillation, a part 
is decomposed, a little charcoal is left behind, and a small quan- 
tity of inflammable gas passes over with the undecomposed sub- 
VOL. XIII. PART I. Q 
