Albumen, properly signifies the white of an egg, but has lately been used in chemistry, to denote likewise one of those elementary constituents of vegetable bodies. which, in its colour and properties, bears an exact resemblance to the animal substance known under this denomination.
The white of eggs, if taken warm from the hen, especially in lukewarm milk, is uncommonly nourishing to the weak and infirm; but, when boiled hard, its nutritive quality is in a great measure destroyed, and it then becomes very difficult of digestion.
If the white of a fresh egg be applied to burns, immediately after the accident, it generally prevents them from rising in blisters : it also tends to abate recent inflammation of the eyes, when spread upon soft linen, and placed over the parts affected. Used as a lotion on the face, it preserves it from sun-burning or freckles, in the heat of summer. On the contrary, a very small portion of the white of an egg, if swallowed in a putrid state, is attended with dreadful effects; such as nausea, horror, fainting, vomiting, diarrhoea, and gripes, accom panied by heat, thirst and fever, while it inflames, or violently stimulates the bile, and, not unlike the plague, promotes a speedy dissolution of the humours.
It is remarkable that, according to Boerhaave, the white of eggs was employed by the reputed Paracelsus, as a menstruum of extraordinary properties; and which greatly contributed to his fame. When boiled hard in the shell, and then suspended in the air by a thread, it dissolves and drops down into a flavourless liquor; which, though destitute of acrid, oily, or saponaceous ingredients, makes a more perfect solution of myrrh than either water, oil, spirits, or even lire itself can effect.
In domestic economy, the white of eggs is usefully employed for clarifying ale, wine, etc. for which purpose it should be mixed with the liquor, and the whole boiled together: thus all the gross particles of the latter will subside, or be carried off with the former, which, by this process, is reduced to a concrete state, and is either precipitated, or combined with, the feculent ingredients of the liquid.
The vegetable albumen is one of those primary constituents of plants, which may be separated by chemical aid, without undergoing any change of their native or inherent qualities. It is found principally in cresses, scurvy-grass, hemlock, and most abundantly in the antiscorbutic and narcotic plants, where it generally resides in the leaves. Its existence may be easily discovered, by mixing the freshly expressed juice of these plants with spirits of wine, or by macerating them with hot water, nearly to the boiling point: in both cases, the albumen will be coagulated and separated from the other fluids in the form of cheesy matter. It is, perhaps, superfluous to observe, that this vegeto-animal production may in times of scarcity serve as a proper substitute for the white of eggs; it being possessed of similar proper-ties. —See the article Eggs.