Citrus limonum. Lemon. Citrus acida. Lime.
Citrus limonum: The Outer Rind and Juice.
Citrus acida: The Juice.
Nat. Ord. — Aurantiaceae. Sex. Syst. — Polyadelphia Icosandria.
Description. — The Lemon tree is an evergreen, about twenty feet in hight, with flexible branches. The leaves are firm, alternate, ovate-oblong, crenate or serrulate, smooth, shining, pale-green, with a winged petiole. The flowers are large, white, with a tinge of pink on the outside, and arise from the smaller branches. The calyx and petals resemble those of the orange, which see. The stamens are from twenty-five to thirty. The ovary is ovate. The fruit is ovate-oblong, uneven, and terminated by a more or less elongated knob, or nipple-like protuberance ; the rind is of a straw-yellow color, and consists, similar to the orange, of two coats, an outer thin and yellow, abounding in a fragrant oil, and an internal thick, whitish and coriaceous. Cysts in the rind concave. Pulp juicy, very acid.
The Lime, Citrus Acida, (or Citrus Limetta, Risso,) is a tree about eight feet in hight, with a crooked trunk and diffuse branches with prickles. The leaves are ovate, obovate, oblong and serrate, being placed upon petioles not winged as in the orange and lemon. The flowers are small and white. Stamens thirty. Fruit ovate or roundish, pale-yellow, with a boss at the point, and about an inch and half in diameter. Cysts in the rind concave. Pulp subacid, flat, slightly bitter.
History. — These plants are of Asiatic origin, and cultivated in the West Indies, and some other tropical countries ; this market is supplied chiefly from the West Indies and the Mediterranean. The exterior rind of the lemon, and the juice of its pulp, are officinal. The rind or lemon peel has a fragrant odor, and a warm, bitter, aromatic taste, which depend upon a volatile oil contained in the minute vesicles with which it is filled, and which, when obtained by distillation with water, or expression, forms the oil of lemon, of commerce. (See Oil of Lemon.) Lemon peel yields its virtues to water, wine, and alcohol.
Lemon juice has an intense, grateful, acid taste, and a slight odor of the rind. It is often kept in a separate state by adding a tenth of strong brandy, or a tenth of alcohol, and then filtering off the mucilage which separates ; it becomes slightly bitterish after a time, but retains its strong acidity undiminished. Lemon syrup is another form in which the juice is preferred. However, it is very liable to spontaneous decomposition, becoming unfit for medical use, hence, citric acid in solution, is its best medicinal substitute ; nine drachms and a half of this acid dissolved in a pint of water, form a solution of the average strength of lemon juice, to which a few drops of oil or essence of lemon may be added. Lemon juice contains 2.5 per cent, of solid matter, of which 1.77 is citric acid, and the rest chiefly mucilage and malic acid. The finest lemons are those which are smoothest and thinnest in the skin.
The lime is smaller than the lemon, with a smoother and thinner rind, oval, rounded at the extremities, of a pale or greenish-yellow color, and abounding in an acid juice, which is chiefly used in the manufacture of citric acid. A variety of the lime tree, C. Limetta, furnishes a fruit from the rind of which is obtained the Oil of Bergamot.
Properties and Uses. — Lemon peel is used in cookery and confectionary, and also in medicine to qualify the taste and increase the power of bitter infusions and tinctures, its virtues are similar to that of the orange peel. The juice of lemon is tonic, refrigerant and antiscorbutic, forming a refreshing and agreeable drink, possessing some medicinal influence, called Lemonade, and which, as with orange juice, may be used freely and advantageously in the febrile and inflammatory diseases, for which this last has been recommended. It may also be added to the nutritive drinks of the sick, as gum water, gruel, barley-water, etc. Its power of preventing and arresting scurvy is unequaled by any other remedy, except a liberal supply of fresh vegetables of the Cruciform family. In scurvy, an ounce or an ounce and a half of the juice per day, is a preventive dose, and when the disease manifests itself, four or six ounces per day will arrest it. Occasionally, but rarely, it fails to effect any benefit in this disease. Ships destined for long voyages should always be provided with a supply of lemon syrup, or citric acid with oil of lemon. Lemon juice has been used as an external application in pruritus of the scrotum, and in uterine hemorrhage after delivery.
Off. Prep. — Acidum Citricum ; Liquor Potassae Citratis; Syrupus Limonis.