Tea-Tree, or Thea, L. a genus of shrubs consisting of two species ; namely, 1. the Bohea, or Black Tea; and, 2. the viridis, or Green Tea; both of which are natives of China and Japan, where they attain the height of 5 or 6 feet.
The Tea-tree produces flowers similar to those of the Dog-rosE, and which are succeeded by fruits of the size of sloes, two or three growing together : - it may be propagated in the temperate climates of Europe, as well as in the Indies, by setting the seeds in holes, about five inches deep, and at regular distances from each other. No particular care is requisite in its culture; but the ground must be cleared of weeds: at the expiration of three years, the leaves are fit to be gathered. Great pains are taken in collecting them singly, at three different times; namely, about the middle of February; in the beginning of March; and in April. Although some writers assert, that they are first exposed to the steam of boiling water, and then dried on copper plates; yet we understand from indubitable authority, that such leaves are simply dried on iron plates, suspended over a fire, till they become dry and shrivelled : when cool, they are packed in tin boxes, to exclude the air, and in that state exported to Europe. It is, however, remarkable that the fresh leaves of this shrub, when used for tea, occasion giddiness, and stupefaction; which noxious properties are dissipated, by roasting them over a moderate fire. Nor is it advisable to drink infusions of this narcotic vegetable, till it be kept at least for 12 months.
Since the commencement of the 17th century, the consumption of tea-leaves has become so general, that, according to the most accurate calculations, there are at present 30 millions of pounds weight annually imported into Europe; three-fifths (or, during war, three-fourths) of which are brought to London, in British vessels. Thus, we are every year drained of a sum of money which, if it were applied to the improvement of national agriculture, would support many thousand industrious families ; by whose labour, during six weeks in the year, all the British empire might be provided with native teas. Nay, it is still more surprizing, that, though every intelligent mind will attest the truth of this remark, yet no landed proprietor, who is in any manner connected with commercial speculations, or who has the least interest in the affairs of India, will rise in a legislative capacity, with a view to remedy, or at least to check, this serious evil; an evil which, like a slow cancer, consumes the vital principle, and exhausts the best sources of a country. As the Tea-tree grows principally between the 30th and 40th degrees of latitude, it might be easily raised in Europe : indeed, from success with which plantations of this shrub have lately been estab-lished by a society of nuns in Franconia, near Wurzburg, there is great reason to believe, that it would also prosper in the southern counties of Britain, if proper attention were paid, till it become habituated to our climate. There are, besides, many indigenous vegetables that may be advantageously substituted ; such are Sage, Balm, Peppermint, and similar spicy plants; the flowers of the Sweet Woodroof ; those of the Burnet, or Pimpernel Rose ; the leaves of Peach and Almond-trees ; the young and tender leaves of Bilberry, and Common Raspberry; and, lastly, the blossoms of the Black-thorn, or Sloe-trEe ; most of which, when carefully gathered, and dried in the shade (especially if they be managed like Indian tea-leaves), can with difficulty be distinguished from the foreign teas, and are at the same time of superior flavour and salubrity.
Teas are divided, in Britain, into three kinds of green, and five of Bohea. The former class includes, 1. Imperial, or Bloom TV a, having a large leaf, a faint smell, and being of a light-green colour : 2. Hyson, which has small curled leaves, of a green shade, inclining to blue: and, 3. Singlo Tea, thus termed from the place where it is cultivated. - The Boheas comprehend : 1. Souchong, which, on in-fusion, imparts a yellowish-green colour. 2. Camho 10, a fine tea, emitting a fragrant violet smell, and yielding a pale shade: it receives its name from the province where it is reared. 3. Pekoe Tea, is known by the small white flowers that are mixed with it. 4. Con-go, has a larger leaf than the preceding variety, and yields a deeper tint to water : and, 5. Common Bohea, the leaves of which are of an uniform, green colour. There are, besides, other kinds of tea, sold under the names of Gunpow der-Tea, etc. which differ from the preceding, only in the minute-ness of their leaves, and being dried with additional care.
Much has been said and written on the medicinal properties of tea : in its natural state, it is doubtless a narcotic, or stupefying plant; on which account, even the Chinese refrain from its use, till it has been divested of this property by the processes above described. If however, good tea be drunk in moderate quantities, with sufficient milk and sugar, it invigorates the system, and produces a temporary exhilaration ; but, when taken too copiously, it is apt to occasion weakness, tremor, palsies, and various other symptoms, similar to those arising from narcotic plants ; while it doubtless contributes to aggravate the hysteric and hypochondriacal complaints, which now-very generally prevail in both sexes. This drug has, farther, been supposed to possess considerable diuretic and sudorific virtues ; which, however, depend more on the quantity of warm water employed as a vehicle, than the quality of the tea itself. Lastly, as infusions of these leaves are the safest refreshment after undergoing great bodily fatigue, or mental exertion, they afford an agreeable beverage to those who are exposed to cold weather ; at the same time tending to support and promote that per spiration which is otherwise liable to be impeded.
Immense quantities of tea-leaves are annually imported by the East India Company, paying a duty of 5l. per cent, according to the value ; and, when taken out for home-consumption, they are subject to the farther charge of 15l. per cent.; if they be under the price of 2s. 6d. per lb. at the Company's sales ; but in case the tea exceed that sum, it is chargeable with the duty of 301. per cent.