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OVOMUCOID. 635
Conalbumin can ho removed from the filtrate, after the complete
crystallization of the ovalbumin, by removing the sulphate by means of
dialysis and coagulating by heat.
Gautier ’
found a fibrinogen-like substance in the white of egg, which was
changed into a fibrin-like body by the action of a ferment.
Ovomucoid. This substance, first observed by Neumeister and
considered by him as a pseudopeptone, and then later studied by Salkow-
ski, is, according to C. Th. Morner,2
a mucoid with 12.65 per cent
nitrogen and 2.20 per cent sulphur. Ovomucoid exists in hens’ eggs
to the extent of about 12 per cent of the total solids.
A solution of ovomucoid is not precipitated by mineral acids nor by
organic acids, with the exception of phosphotungstic acid and tannic
acid. It is not precipitated by metallic salts, but basic lead acetate and
ammonia render it insoluble. Ovomucoid is thrown down by alcohol,
but sodium chloride, sodium sulphate, and magnesium sulphate give
no precipitates cither at the ordinary temperature or when the salts are
added to saturation at 30° C. Its solutions are not precipitated by an
equal volume of a saturated solution of ammonium sulphate, but are
precipitated on adding more salt thereto. The substance is not pre-
cipitated on boiling, but the part which has become insoluble in cold
water and which has been dried, is dissolved by boiling water. Zanetti
has prepared glucosamine on splitting ovomucoid with concentrated
hydrochloric acid, and Seemann found that the quantity of glucosamine
in ovomucoid was 34.9 per cent.3
Ovomucoid may be prepared by removing all the proteins by boil-
ing with the addition of acetic acid, and then concentrating the filtrate
and precipitating with alcohol. The substance is purified by repeated
solution in water and precipitation with alcohol.
Paxormow believes that the eggs of other birds, such as the pigeon and duck,
contain a special protein in the egg-white, which is not identical with that of the
hen’s egg. Worms 4
has prepared a crystalline albumin from the white of the
turkey eggs which contained 15.37 per cent N, 1.6 per cent S and had a specific
rotation of (o;)d = —34.9°.
The mineral bodies of the white of egg have been analyzed by
Poleck and Weber.5 They found in 1000 parts of the ash: 276.6-
iCompt. Rend., 135.
2
R. Neumeister, Zeitschr. f. Biologic, 27; Salkowski. Centralbl. f. d. med. Wis-
senseh., 1893, 513 and 706; C. Morner, Zeitsch. f. physiol. Chem., 18 and 80. See
also Langstein, Hofmeister’s Beitrage, 3 (literature).
3
Zanetti, Chem. Centralbl., 1898, 1; Seemann, cited from Langstein, Ergebnisse
der Physiol., 1, Abt. 1, 86.
4
Panormow, see Bioch. Centralbl., 5; Worms, cited from Chem. Centralbl., 1906,
2, 1508.
5
Cited from Hoppe-Seyler, Physiol. Chem., 778.
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