Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 3, 1802).djvu/349

Rh  to their roots, by means of the circulating fluids, it is believed to promote their growth; though, if it be absorbed too copiously, and rapidly, it is unfavourable to vegetation. On the contrary, a very large proportion is requisite to conduce to the growth, and to nourish the vitality of animals.—Lastly, oxygen is supposed to exist in all bodies, whether of the vegetable, animal, or mineral kingdoms, and particularly in certain metallic calces or oxydes; such as ruddle, calamine, and burnt clay; which, on accunt of the large quantity of the acidifying principle they contain, are conjectured to be of considerable utility as manures.  OXYMEL, in pharmacy, a mixture of honey and vinegar, which are boiled to the consistence of a syrup.

Oxymel of Garlic, is prepared by boiling, for a short time, half a pint of vinegar together with two drams of caraway, and a similar quantity of sweet fennel-seeds, in a glazed earthen vessel; when an ounce and a half of garlic, cut in slices, should be added, and the whole closely covered. As soon as the mixture becomes cold, the liquor must be expressed, and mixed with ten ounces of clarified honey, by the heat of a water-bath. This preparation is sometimes taken in the humid asthma, for promoting expectoration, and the fluid secretions; being a medicine of considerable efficacy, though it acquires an unpleasant flavour from the garlic.

Oxymel of Squills, consists of three parts of honey, and two parts of vinegar of squills, which are boiled in a glass vessel to the consistence of a syrup. It is an useful expectorant, and resolvent in asthmas, coughs, and similar complaints, when the patient is oppressed with viscid mucus: it is generally given in doses of two or three small tea-spoonfuls, together with a little cinnamon, or other aromatic water, to prevent the nausea which it frequently excites. In larger doses, it may be occasionally administered as an emetic.  OYSTER, or Ostrea, L. a genus of shell-fish, comprising thirty-one species, which are distinguished chiefly by the peculiar formation of their shells.—The principal of these is, the Common Oyster, taken at the mouth of rivers, in clear waters, on the eastern coast of Britain. Among the most esteemed for their delicious flavour, are the Malden and Colchester Oysters, caught in the Pent-Burnham, Malden, and Colne waters; or near the mouth of the Thames, which last are said to rival those of Colchester.

Oysters cast their spawn in the month of May, when they become subject to a periodical affection; the male-fish, having a black substance in the fin, is black-sick; and the female oyster, from a milky-juice in its fin, is said to be white-sick: in June and July they begin to recover; and are in August perfectly sound.—They are saltish in the pits, more saline in the beds or layers, and very salt in the sea.

These shell-fish should be fresh, tender, and moist; as the want of fresh water renders them hard, bitter, and unpalatable.—Epicures give the preference to such as are edged with a small brown fringe, or beard, and which they erroneously suppose to be females. It is Rh