1794. Linnaeus was induced to think that there were two species of tea-plant, one of which produced the black, and the other the green teas; but later observations do not confirm this. When the leaves of black and green tea are expanded by hot water, and examined by the botanist, though a difference of character is perceived, yet this is not sufficient to authorize considering them as distinct species. The tea-tree flourishes best in temperate regions; in China it is indigenous. The part of China where the best tea is cultivated, is called by us the "tea country." The cultivation of the plant requires great care. It is raised chiefly on the sides of hills; and, in order to increase the quantity and improve the quality of the leaves, the shrub is pruned, so as not to exceed the height of from two to three feet, much in the same manner as the vine is treated in France. They pluck the leaves, one selecting them according to the kinds of tea required; and, notwithstanding the tediousness of the operation, each labourer is able to gather from four to ten or fifteen pounds a day. When the trees attain to six or seven years of age, the produce becomes so inferior that they are removed to make room for a fresh succession, or they are cut down to allow of numerous young shoots. Teas of the finest flavour consist of the youngest leaves; and as these are gathered at four different periods of the year, the younger the leaves the higher flavoured the tea, and the scarcer, and consequently the dearer, the article.
1795. The various names by which teas are sold in the British market are corruptions of Chinese words. There are about a dozen different kinds; but the principal are Bohea, Congou, and Souchong, and signify, respectively, inferior, middling, and superior. Teas are often perfumed and flavoured with the leaves of different kinds of plants grown on purpose. Different tea-farms in China produce teas of various qualities, raised by skilful cultivation on various soils.
1796. Tea, when chemically analyzed, is found to contain woody fibre, mucilage, a considerable quantity of the astringent principle, or tannin, a narcotic principle, which is, perhaps, connected with a peculiar aroma. The tannin is shown by its striking a black colour with sulphate of iron, and is the cause of the dark stain which is always formed when tea is spilt upon buff-coloured cottons dyed with iron. A constituent called Theine has also been discovered in tea, supposed to be identical with Caffeine, one of the constituents of coffee. Liebig says, "Theine yields, in certain processes of decomposition, a series of most remarkable products, which have much analogy with those derived from uric acid in similar circumstances. The infusion of tea differs from that of coffee, by containing iron and manganese. We have in tea, of many kinds, a beverage which contains the active constituents of the most powerful mineral springs, and, however small the amount of iron may be which we daily take in this form, it cannot be destitute of influence on the vital processes."
1797. Chinese tea has frequently been adulterated in this country, by the admixture of the dried leaves of certain plants. The leaves of the sloe, white thorn, ash, elder, and some others, have been employed for this purpose; such as the leaves of the speedwell, wild germander, black currants, syringa, purple-spiked willow-herb, sweet-brier, and cherry-tree. Some of these are harmless, others are to a certain degree poisonous; as, for example, are the leaves of all the varieties of the plum and cherry tribe, to which the sloe belongs. Adulteration by means of these leaves is by no means a new species of fraud; and several acts of parliament, from the time of George II., have been passed, specifying severe penalties against those guilty of the offence, which, notwithstanding numerous convictions, continues to the present time.
1798. In the purchase of tea, that should be chosen which possesses an agreeable odour and is as whole as possible, in order that the leaf may be easily examined. The greatest care should be taken that it has not been exposed to the air, which destroys its flavour.
1799. It would be impossible, in the space at our command, to enumerate the various modes adopted in different countries for "making coffee;" that is, the phrase commonly understood to mean the complete preparation of this delicious beverage for drinking. For performing this operation, such recipes or methods as we have found most practical will be inserted in their proper place; but the following facts connected with coffee will be found highly interesting.
1800. The introduction of coffee into this country is comparatively of recent date. We are assured by Bruce that the coffee-tree is a native of Abyssinia, and it is said to have been cultivated in that country from time immemorial.
1801. It appears that coffee was first introduced into England by Daniel Edwards, a Turkey merchant, whose servant, Pasqua, a Greek, understood the manner of roasting it. This servant, under the patronage of Edwards, established the first coffee-house in London, in George Yard, Lombard Street. Coffee was then sold at four or five guineas a pound, and a duty was soon afterwards laid upon it of fourpence a gallon, when made into a beverage. In the course of two centuries, however, this berry, unknown originally as an article of food, except to some savage tribes on the confines of Abyssinia, has made its way through the whole of the civilized world. Mahommedans of all ranks drink coffee twice a day; it is in universal request in France; and the demand for it throughout the British isles is daily increasing, the more especially since so much attention has been given to mechanical contrivances for roasting and grinding the berry and preparing the beverage.
1802. Of the various kinds of coffee the Arabian is considered the best. It is grown chiefly in the districts of Aden and Mocha; whence the name of our Mocha coffee. Mocha coffee has a smaller and rounder bean than any other, and likewise a more agreeable smell and taste. The next in reputation and quality is the Java and Ceylon coffee, and then the coffees of Bourbon and Martinique, and that of Berbice, a district of the colony of British Guiana. The Jamaica and St. Domingo coffees are less esteemed.
1803. A considerable change takes place in the arrangement of the constituents of coffee by the application of heat in roasting it. Independently of one of the objects of roasting, namely, that of destroying its toughness and rendering it easily ground, its tannin and other principles are rendered partly soluble in water; and it is to the tannin that the brown colour of the decoction of coffee is owing. An aromatic flavour is likewise developed during torrefaction, which is not perceived in the raw berry, and which is not produced in the greatest perfection until the heat has arrived at a certain degree of temperature; but, if the heat be increased beyond this, the flavour is again dissipated, and little remains but a bitter and astringent matter with carbon.