120 Professor Curistrson on the Chemical Examination of 
lamp, and then by a third distillation from the vapour-bath, is 
limpid and colourless, like sulphuric ether, and its density is 779. 
From the trials I have made, I consider that the Rangoon pe- 
troleum, when distilled on the large scale, will yield nearly a 
third of its volume of this colourless naphtha. 
IT need scarcely observe, that, in eastern countries, where the 
fresh juice of the caoutchouc tree cannot be procured, the naph- 
tha from the Rangoon petroleum may prove a useful article. 
Like other kinds of naphtha it freely dissolves, or rather softens, 
caoutchouc ; which, after the evaporation of the solvent, is reco- 
vered with its original properties. When it is to be used for this 
purpose, however, it must be carefully separated by distillation 
from the crystalline matter I am presently to describe, which rises 
as the distillation advances, and gives the naphtha a yellow co- 
lour. For, if any material proportion of this impurity be pre- 
sent, the caoutchouc solution dries very slowly, and long retains a 
greasy surface. 
The yellowish, concrete, crystalline matter, like the petro- 
leum itself, is not acted on by the caustic alkalies, or by the 
strong acids. Alcohol dissolves it very sparingly; ether and the 
essential oils, freely and entirely. None of these solvents, there- 
fore, is of any use for separating the crystalline matter from the 
mass. But I have succeeded in procuring it in a state of purity 
by the following process : 
The mass being cooled down to about 40° Fahr. it was spread 
out on filtering paper, and then subjected to strong pressure be- 
tween many folds of common blotting paper. In this manner, an 
oily-like matter was taken up by the paper, and a pale yellowish- 
white crystalline substance was left, which was subsequently de- 
prived of its remaining colour by repeated solution in boiling 
ether and recrystallization. ther dissolved it largely, forming a 
pale yellow solution, which, on being cooled by immersing the 
vessel in very cold water, became a soft mass of interwoven crys- 
tals. This mass was then taken out, spread quickly on filtering 
