Page:Indian Medicinal Plants (Text Part 2).djvu/543
and scurvy. Externally as rubefacient, and, when roasted, as a poultice. Considered by natives hot and pungent, useful in flatulency. Said to prevent the approach of snakes and venomous reptiles. (Baden-Powell.)
They are also described as aphrodisiac. Eaten raw they are emmenagogue. The juice rubbed on insect-bites is said to allay irritation. The centre portion of a bulb, heated and put into the ear, is good for ear-ache. The warm juice of the fresh bulb is also used for this purpose.
The seeds yield a colourless clear oil used in medicine.
Onion tea will often relieve sleepless and irritable children when opium and other narcotics have failed. Let the opium go, and try onions first.— Family Doctor, June 19, 1886.
The expressed juice of the bulbs, with salt dropped in the eye, is said to be useful in night blindness. A poultice of bulb is also used. (B. D. B.).
" The bulb is crushed and the acrid smell is utilised emitted like smelling-salts for fainting and hysterical fits." (S. M. Robb, Ahmedabad). " Said to increase the peristaltic action of the intestines, and is prescribed in obstruction. Used in jaundice, hæmorrhoids, and prolapsus ani, also in hydrophobia. As an external application, onions are used in scorpion bites and to allay irritation in skin diseases. They have antiperiodic properties attributed to them, and are said to mitigate cough in phthisis, and mixed with vinegar, used in sore- throat." (Surg. J. McConaghey, Sbabjahanpore.) Used as a decoction in cough." (Surg. Ross, Delhi). Onion juice, mixed with mustard oil in proportion, is used as a liniment to allay rheumatic pains. (Watt's Dictionary).
Onions yield 0.005 per cent, of their weight of a dark-brown essential oil which does not contain oxygen, has a sp-gr. at 8"7°=1.041, and exhibits a rotation of 5° in a 100 mm. tube ; a small quantity of crystals separate on cooling it in a freezing mixture. As it decomposes when distilled at the ordinary pressure, it was fractionated under a pressure of 10 mm.
The main portion of the oil consists of a compound, C6H12S2, an oil of sp. gr. 1.0234 at 12°, which boils at 75-83° (10 mm.), and is converted into the compound C6H12S2 on treatment with potassium ; this new compound boils at 68-69° (10 mm.), and seems to be present in small quantity in the original oil. The compound C6H12S2 is converted by zinc-dust into a mono-sulphide, C6H12S2