Allium Cepa.

Botanical name: 

Related entry: Allium sativum

The fresh bulb of Allium Cepa, Linné (Nat. Ord. Liliaceae). Common in cultivation everywhere.
Common Name: Onion.

Principal Constituent.—A colorless oil, composed chiefly of a sulphur compound (C6H12S2).
Preparations.—1. Tincture of Red Onion. 5 to 60 drops.
2. Syrup of Onion. Dose, 1 to 2 fluidrachms.

Action and Therapy.—External. Onion is rubefacient. A poultice of onion with vinegar gives relief to inflamed corns and bunions. Roasted onion makes an efficient poultice for acute broncho-pulmonic inflammations, especially of young children, when local applications are desired. Onion poultices are objectionable only when made too heavy, carelessly applied, or when applied to open surfaces.

Internal. Onion is stimulant, expectorant, and diuretic. A syrup of onion, prepared by drawing the juice with sugar, is a very effectual expectorant cough medicine for infants, young children, and old persons. If given in moderate quantities it is very soothing; if too freely administered it may cause nausea and disorder digestion. It, together with the onion poultice, are among the good things inherited from domestic medication, and might well be considered in preference to less safe and less depressing pulmonic medication. A tincture of red onion is useful in gravel and other urinary disorders with passages of blood, pus, and mucus. The dose is from 5 to 10 drops in water. It is sometimes given with an equal quantity of tincture of Xanthium Strumarium.


The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.