Tea

Tea, one of the most important of food-adjuncts, now in daily use probably by half the human race, is an infusion of the leaves of the camelliaceous evergreen shrub Thea assamica and its Chinese cultivated form T. sinensis, of which there are two distinct races, T. Bohea and, T. Viridis. T. assamica reaches twenty feet in height in the shade of the moist jungles of Assam, where it is indigenous; and has smooth, thick, leathery leaves, sometimes over nine inches long, dotted with translucent oil-glands, and having in their mesophyll, or inner cellular tissue, sphaeraphides and large branching thick-walled cells or idloblasts. Thea differs from Camellia in having its solitary white flowers directed slightly downwards, each having five persistent sepals with bracts below them, five to nine petals, as many inner or free stamens, and only three carpels, each forming a one-seeded chamber to the ovary, with a distinct style. The cultivated Chinese shrubs are only three to five feet high, much branched, with numerous leaves, not exceeding four inches in length. When young the leaves are densely hairy beneath. T. viridis, the more northern variety, has larger, brighter-green leaves, and is hardier than T. Bohea.

Tea (Chinese cha, pwnounced tay at Amoy) was certainly used in China in the 6th century A.D., having traditionally been introduced from India by a missionary. From China its cultivation spread in the 13th century to Japan; but the substance was unknown in Europe previous to 1517, and the habit of tea-drinking was not brought westward till the Dutch established themselves at Bantam early in the 17th century. Until 1677 England was entirely supplied from Java, the price ranging from £10 to 15s. per lb. Thomas Garway, founder of Garraway's Coffee-house, in 1660 offered it for sale at prices ranging from 50s. to 15s. In 1660 a duty of 8d. per gallon was imposed on the sale of the infusion, and in 1689 one of 5s. per lb. and 5 per cent. of the value on leaf-tea. The East India Company bought tea first in Madras and Surat and afterwards at Amoy, and the high duties, coupled with their monopoly, led to much smuggling, adulteration, and manufacture of imitation tea. At the close of the 17th century about 20,000 lbs. were imported annually, the price averaging 16s. per lb., and the amount of duty-paid tea consumed in this country rose, in spite of heavy taxation, from less than 1-1/2 million lbs. in 1728 to over 10 million in 1784, over 20 million in 1795, and over 30 million in 1833. The consumption of tea in the United Kingdom in 1840 exceeded 1 lb. per head of the population; in 1860 it exceeded 2-1/2 lbs.; in 1880, 4 lbs.; and at the present time it exceeds 5 lbs. per head, the same proportion as in China, where the total annual consumption has been estimated at 2,000 million lbs. Our total import was nearly 207 million lbs. in 1880 and nearly 270 million lbs. in 1897, 231 million of the latter being for home consumption. The United States consume 1-1/2 lb. per head; Holland, less than a lb.; Russia, less than 1/2 lb.; but the Australian colonies nearly 10 lbs. per head. More than half our supply is now derived from India and Ceylon, though the cultivation of tea in Assam practically dates from 1840, and in Ceylon from 1876, Tea-planting has also been successfully established in Natal.

The tea-plant requires a deep, friable, moist, but well-drained soil, and a warm, equable, moist olimate; and cheap labour is an essential to success in the industry. The leaves are picked so as not to injure their axillary buds, and the younger the leaves on the "flush" or shoot the better the quality. A tree will yield 1/5 lb. per annum, which will amount to from 300 to 350 lbs. per acre. In making black tea, the picked leaves are withered until limp; rolled, generally by hand; fermented; exposed, if possible, to the sun for an hour; and immediately fired, or dried by hot air or charcoal fumes. Green tea is made in other districts, but from the same varieties, by sweating, softening, and rolling fresh unwithered leaves, repeating this rolling, and heating considerably. Chinese gteen tea is artificially coloured; but that from India is not. Indigo, Prussian blue, French chalk, and turmeric are the chief materials used for facing green tea, the most spurious concoctions being known to the Chinese as lie tea. the chief commercial varieties of tea are pekoe, souchong, congou, and bohea among b1ack teas, and gunpowder, hyson, and caper among green teas, "pekoe" denoting the white hairs of the youngest leaves, Brick tea, a coarse compressed variety, is used almost exclusively in Central Asia, where it is often eaten as a vegetable with milk and fat. Tea contains from .4 to 1 per cent of a fragrant, narcotic essential oil; from 1 to 3 per cent. of the white, crystalline alkaloid theine (C₈H₁₀N₄O₂), identical with caffeine and allied to theobromine, and from 12 to 18 per cent. of tannin. Chinese teas being richer in theine and poorer in tannin than those of India. Unless infused in boiling water, neither the theine nor the tannin is properly extracted. Ten minutes' infusion extracts all the theine and essential oil, upon which the tea depends for its stimulating effect upon the brain and the respiratory system. More prolonged stewing only extracts more of the indigestible tannin. Tea has little nutritive value, apart from the sugar and milk often taken with it: in excess it induces nervous irritability and insomnia; but, in ihe words of Lo Yu, who wrote before 900 A.D., "it tempers the spirits and harmonises the mind, dispels lassitude and relieves fatigue, awakens thought and prevents drowsiness, lightens or refreshes the body, and clears the perceptive faculties."