Scientific reasons which are self-convincing may be readily adduced for prescribing all our best known native herbal medicines. Among them the Elder, Parsley, Peppermint, and Watercress may be taken as familiar examples of this leading fact. Almost from time immemorial in England a "rob" made from the juice of Elderberries simmered and thickened with sugar, or mulled Elder wine concocted from the fruit, with raisins, sugar, and spices, has been a popular remedy in this country, if taken hot at bedtime, for a recent cold, or for a sore throat. But only of late has chemistry explained that Elderberries furnish "viburnic acid," which induces sweating, and is specially curative of inflammatory bronchial soreness. So likewise Parsley, besides being a favourite pot herb, and a garnish for cold meats, has been long popular in rural districts as a tea for catarrh of the bladder or kidneys; whilst the bruised leaves have been extolled as a poultice for swellings and open sores. At the same time, a saying about the herb has commonly prevailed that it "brings death to men, and salvation to women." Not, however, until recently has it been learnt that the sweet-smelling plant yields what chemists call "apiol," or Parsley-Camphor, which, when given in moderation, exercises a quieting influence on the main sensific centres of life--the head and the spine. Thereby any feverish irritability of the urinary organs inflicted by cold, or other nervous shock, would be subordinately allayed. Thus likewise the Parsley-Camphor (whilst serving, [4] when applied externally, to usefully stimulate indolent wounds) proves especially beneficial for female irregularities of the womb, as was first shown by certain French doctors in 1849. Again, with respect to Peppermint, its cordial water, or its lozenges taken as a confection, have been popular from the days of our grandmothers for the relief of colic in the bowels, or for the stomach-ache of flatulent indigestion. But this practice has obtained simply because the pungent herb was found to diffuse grateful aromatic warmth within the stomach and bowels, whilst promoting the expulsion of wind; whereas we now know that an active principle "menthol" contained in the plant, and which may be extracted from it as a camphoraceous oil, possesses in a marked degree antiseptic and sedative properties which are chemically hostile to putrescence, and preventive of dyspeptic fermentation.