ulterate spirits of turpentine without detection. I give the figures
for a few imitations or adulterations:

Sp. gr. B.P.
No. 1 0.821 137 deg. C.
No. 2 0.884 165 deg. C.
No. 3 0.815 150 deg. C.
No. 4 0.895 156 deg. C.

There is a considerable difference in the flashing point, no doubt due
to the longer or shorter exposure of the crude turpentine, by which
more or less of the volatile portion escapes.

* * * * *

ON THE OCCURRENCE OF PARAFFINE IN CRUDE PETROLEUM.[1]

[Footnote 1: An abstract of thesis by E.A. Partridge, class of
'89, Univ. of Pa. Read before the Chemical Section of the
Franklin Institute by Prof. S.P. Sadtler.]

It is well known that the paraffine obtained by the distillation of
petroleum residues is crystalline, while that obtained directly (as in
the filtration of residuum) is amorphous. Ozokerite or ceresine
differs but slightly from paraffine, the principal distinction being
want of crystalline structure in it as found. Other characteristics,
such as the melting point, specific gravity, etc., vary in both, and
so are not of importance in a comparison. Hence it has been asked, Is
the paraffine occurring in petroleum and ozokerite identical with that
which is produced by their distillation? As crystalline paraffine
could be obtained from ozokerite by distillation alone, many persons
have supposed that it was engendered in the process. Recently,
however, crystalline paraffine has been obtained from ozokerite by
dissolving the latter in warm amyl alcohol; on cooling the greater
part separates out in crystals having the luster of mother-of-pearl.
By repetition of this process, a substance is obtained that is
scarcely to be distinguished from the paraffine obtained by
distillation. Apparently there exists then in ozokerite, together with
paraffine, other substances not capable of crystallization which keep
the paraffine from crystallizing. These colloids appear to be
separated by amyl alcohol in virtue of their greater solubility in
that menstruum. It is also reasonable to suppose that they undergo
change or decomposition by distillation.

So as petroleum residues are amorphous, and the crystalline paraffine
is first produced by distillation, it has been argued that the
paraffine present in crude petroleum is approxi