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 approximately the same thing
as ozokerite.
This, however, is not sufficient to establish the pyrogenic origin of
all crystallized paraffine, as crystals can be obtained from the
amorphous residues by distillation at normal or reduced pressure or in
a current of steam. To explain these facts two assumptions are
possible. Either the chemical and physical properties of all or some
of the solid constituents are changed by the distillation, and the
paraffine is changed from the amorphous into the crystalline variety,
or the change produced by the distillation takes place in the medium
(i.
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