This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Limon Pharm, Lond. Limonia mala Pharm, Edinb. Lemons: the fruit of the malus limonia fructu acido Pharm. Lond. malus limonia acida C. B. Citrus Limon Linn. a tree refembling the orange; from which it differs chiefly in the leaves having no appendages at the bottom; and in the fruit having a nipple-like production at the end: it is a native of Asia, and cultivated in the warmer parts of Europe, from. whence we are supplied with the fruit. There are many varieties of this tree in regard to the fruit: by Linnaeus, the feveral citrons, as well as lemons, are reckoned varieties of one species, which is distinguished from those of the orange kind, only by the pedicles of the leaves being naked. The terms citron and lemon have been often confounded together; what is commonly called citron by the French (a) and Germans(b) being our lemon, and their lemon our citron.
The yellow rind of lemons is a grateful aromatic, of common use in stomachic tinctures and infusions, and for rendering other medicines acceptable to the palate and stomach: its flavour is one of those which is best adapted for accompanying medicines of the bitter kind. It is less hot than orange peel, and yields in distillation a less quantity of essential oil: the oil is extremely light, almost colourless, in smell nearly as agreeable as the fresh peel, and frequently employed as a perfume: it is generally brought to us from the southern parts of Europe, under the name of essence of lemons. The flavour of the lemon peel is more perishable in keeping than that of orange peel, yet does not rife so easily in distillation with spirit of wine: for a spirituous extract, prepared from the rind of lemons, retains the aromatic taste and smell of the peel in a much greater degree than an extract prepared in the same manner from that of oranges. After digestion in the spirit, lemon peel proves tough, that of oranges crisp.
(a) Codex medicamentarius facultatis Parifienjis, p. xxxviii & Ixx.
(b) Hoffman, Dissert. de citriis, Opera omnia, supplement. ii. par. i. p. 720.
The juice of lemons differs from that of oranges only in being more acid. Six drams of it saturate about half a dram of sixt alkaline salt: this mixture, with the addition of a small quantity of some grateful aromatic water or tincture, as simple cinnamon water, is given in cases of nauseae and Teachings, and generally abates, in a little time, the severe vomitings that happen in fevers, when most other liquors and medicines are thrown up as soon as taken: it is used also as a saline aperient in icterical, hydropical, inflammatory and other disorders. A syrup made by dissolving fifty ounces of fine sugar in a quart † or two pounds and a half ‡ of the depurated juice, is mixed occasionally with draughts and juleps as a mild antiphlo-giftic, and sometimes used in gargarisms for inflammations of the mouth and tonsils. The London college also direct the infpiffated juice to be kept.