Onion

Onion (Fr. oignon, from Lat. unio, 'a pearl,' but in Columella signifying a kind of onion), the name given to a few species of the genus Allium (q.v.), and particularly to A. cepa (Lat. cepa), a biennial bulbous-rooted plant. The bulb is simple, and in the common variety is solitary, showing little tendency to produce lateral bulbs. The native country of the onion is shrouded in obscurity. It is supposed to be indigenous to India, whence it passed into Egypt, where it was cultivated 2000 years before the Christian era. Thence probably it was transmitted to Greece and Italy, and gradually spread over Europe, in most countries of which it has been cultivated from time immemorial. The onion contains a white acrid volatile oil, holding sulphur in solution, albumen, uncrystallisable sugar and mucilage, phosphoric acid, both free and combined with lime, acetic acid, citrate of lime, and lignin. The acrid qualities, while present in every part of the plant, are most concentrated in the bulb. When it is cultivated in warm countries the acridity decreases, while the saccharine qualities increase; hence the comparative mildness of Spanish and Portuguese onions. So mild and sweet are these that the peasantry of Spain and Portugal eat them raw with bread. Indeed, the onion forms a very important article of food with the poor of those countries. It is very nutritious and easily digested, yet does not agree with all stomachs when cooked otherwise than boiled. In boiling, the essential oil is dissipated and the onion thereby rendered more agreeable to delicate stomachs. The onion is stimulant, diuretic, expectorant, and rubefacient. The acid of the juice has the reputation of dissolving calculus in the bladder. The pulp of the bulb by fermentation is converted into vinegar, and with the addition of dregs of beer yields by distillation an alcoholic liquor. The pulp of roasted onion with olive-oil forms an excellent anodyne and emollient poultice to suppurating tumours. There are many varieties of the onion in cultivation in Britain, which have been obtained by natural seminal variation and by careful selection. In recent years great progress has been made by these means in the direction of increasing the size of the bulb, and there are now varieties which under good cultivation surpass even the large Spanish onion of the shops in size, but they lack the delicate flavour of the latter. There is great diversity in the keeping qualities of the bulbs of the different varieties. Those having small, compact bulbs keep best and for the longest time. By a proper selection of sorts home-grown onions may be had either green or matured all the year round. The Tripoli Trebon and White Lisbon are sown in August to supply green onions in spring; and if transplanted from the seed-bed to rich ground at that season they grow to very large size by September, when they reach maturity. James's Keeping, Strasburg, and Brown Globe are varieties which keep long and are sown in February and March for the main crop. The onion delights in rich, moist soil deeply trenched; when very large bulbs are desired it is hardly possible to overdo the ground with manure. When the crop ripens, which is known by the central leaves ceasing to grow and the lower ones going to decay, the bulbs are taken up and spread out thinly on a dry surface in the open air till they are quite dry; they are then stored in a loft where, in mild weather, they may have plenty of air but be protected from frost and damp.—The Potato-onion, so called because it reproduces itself underground by division of the bulb, is a perennial variety of the onion which also bears the names Egyptian and Ground Onion. It is much favoured by cottagers, in Scotland particularly. A legend that it was first brought to Britain by the British army from Egypt in 1805 is without foundation, as it was cultivated long before that time in the country. Pickling onions are usually obtained by sowing the small silver-skinned variety on poor soil in spring. The Tree-onion, so named because, instead of producing seeds after flowering, the ovaries develop viviparous bulbs by which the plant is propagated, is rarely cultivated except as a curiosity. The Welsh Onion, or Cibol (A. fistulosum), produces no bulb, but merely a fleshy stem like the leek. It is a native of Siberia, and being very hardy was formerly grown in gardens to supply green onion tops in spring for salads and the flavouring of soups and sauces. Being rather coarse in flavour, however, it has been superseded by the milder flavoured kinds, which are sown in August. It is the true syboe of the Scotch, although the term has come to be applied to green or young onions of whatsoever kind.