Domestic Encyclopædia (1802)/Egg
EGG, a body formed in certain female animals, and which contains an embryo or fetus, beneath a cortical surface, or shell. This shell is lined throughout with a thin, but tough membrane, which, dividing at or near the obtuse end of the egg, forms a small bag, and contains what is called the albumen, or white, and the vitellus, or yolk.
The chick in the egg is first nourished by the white, and when that is consumed, by the yolk.—A short time before the exclusion of the animal, the whole of the yolk is taken into its abdomen, and the shell, at the obtuse end, frequently appears cracked, winch is occasioned by the instinctive operation of the beak.
Eggs vary much in their colour, size, and form, according to the birds that deposit them, and the different modes of dressing them. Those chiefly used for culinary purposes are the new laid eggs of hens, being without exception the most wholesome.
Eggs are an agreeable and nourishing food; but they ought to be perfectly fresh, and gradually coagulated in hot water, from 5 to 10 minutes, instead of being boiled. To ascertain whether they have been well preserved, it is only necessary to examine their transparency by a candle, and to reject all such as appear of a turbid colour: fresh eggs also, on being exposed to the fire, will exhale a perceptible moisture.
Among the various methods contrived, of preserving eggs for the winter-season, the chief requisite is to exclude every access to the air. For this purpose, solutions of lime, with the addition of alkalis, have been employed; but these, as well as the varnishing of eggs with wax, are too expensive for general use. The greasing of eggs with unctuous substances, such as mutton fat, oil, &c. has also been practised; but it is neither cleanly, nor calculated to effect the object intended. One of the best methods, seems to be that of covering the eggs with a cheap varnish, by which the air will be prevented from penetrating the pores; or of suspending them in running water, by means of a net.
The shells of eggs serve for various purposes, but chiefly as a colour: when finely levigated, they are preferred to flake-white. They are prepared by peeling off the inner skin, and after being finely pulverized, the powder is carefully washed.—See Colour-making, vol. ii. p. 36.
The yolks of eggs are employed in different medicinal ways, but most frequently in emulsions. One yolk, if gradually beaten up with three ounces of pure water, and reduced to the utmost degree of thinness, has been found of great utility in removing contractions of the limbs. The whites are chiefly applied externally, in the preparation of eye-waters, on account of their cooling, agglutinating, and astringent qualities. They have also been used with advantage, in burns, and are recommended as a specific for the jaundice, of which we have had no experience.