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634 ORGANS OF GENERATION.
conalbumin is a mixture or not, and the question concerning the unity
of the crystallizable ovalbumin is also disputed. According to Bond-
zynski and Zoja, crystallizable ovalbumin is a mixture of several albumins
having somewhat different coagulation temperatures, solubilities, and
specific rotations, while Hofmeister and Langstein on the contrary
believe that crystallizable ovalbumin is a unit. The reports as to the
specific rotation of the different fractions unfortunately differ, and the
elementary analyses have also given no positive results, as a variation
of 1.2-1.7 per cent has been observed in the quantity of sulphur. Accord-
ing to the consistent analyses of Osborne and Campbell and of Lang-
stein, the conalbumin contains about 1.7 per cent sulphur and about
16 per cent nitrogen, while the ovalbumin contains on an average about
15.3 per cent nitrogen. Langstein 1
obtained 10-11 per cent glucosa-
mine from ovalbumin and about 9 per cent from conalbumin. The
ovalbumin, like the conalbumin, has the properties of the albumins in
general, but differs from seralbumin in that the specific rotation
is lower. It is quickly made insoluble by alcohol and is precipitated
by a sufficient quantity of HC1, but dissolves in an excess of acid with
greater difficulty than the seralbumin. The products isolated by
Abderhalden and Pregl 2
on the hydrolysis of ovalbumin do not show
anything of special interest.
As in the past certain doubts have existed as to the purity and chem-
ical unity of the ovalbumins, or also of the crystalline ovalbumin, so now
this doubt has become still stronger since ovalbumin has been pre-
pared partly free from phosphorus and partly with a variable phos-
phorus content of 0.1-3.06 per cent (Kaas, Willcock and Hardy 3
).
In preparing .crystalline ovalbumin, mix, according to Hofmeister,
the beaten white of egg free from foam with an equal volume of a saturated
ammonium-sulphate solution, filter off the globulin, and allow the nitrate
to evaporate slowly in thin layers at the temperature of the room. After
a time the masses which separate out are dissolved in water, treated
with ammonium sulphate-solution until they begin to get cloudy, and
are allowed to stand. After repeated recrystallization the mass is either
treated with alcohol, which makes the crystals insoluble, or they are
dissolved in water and purified by dialysis. From these solutions the
proteid does not crystallize again on spontaneous evaporation. (See also
page 633, footnote 2, for the Hopkins and Pinkus method.) Will-
cock 4
has recently found that* magnesium sulphate can also be used in
the crystallization of ovalbumin.
1
Zeitsrhr. f. physiol. Chem., 31.
-
Ibid., 4«.
3
Kaas, Monatsh. f. Chem., 27; Willcock and Hardy, cited from Chem. Centralbl.,
1907, 2, 821.
4
Journ. of Physiol., 37.
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