The plant in cultivation about Canton, from which the Canton teas are made, is known to botanists as the _Thea bohea_; while the more northern variety, found in the green-tea country, has been called _Thea viridis_. The first appears to have been named upon the supposition, that all the black teas of the Bohea Mountains were obtained from this species; and the second was called _viridis_, because it furnished the green teas of commerce. These names seem to have misled the public; and hence many persons, until a few years ago, firmly believed that black tea could be made only from _Thea bohea_, and green tea only from _Thea viridis_. In his _Wanderings in China_, published in 1846, Mr Fortune had stated that both teas could be made from either plant, and that the difference in their appearance depended upon manipulation, and upon that only. But the objection was made, that although he had been in many of the tea-districts near the coast, he had not seen those greater ones inland which furnish the teas of commerce. Since that time, however, he has visited them, without seeing reason to alter his statements. The two kinds of tea, indeed, are rarely made in the same district; but this is a matter of convenience. Districts which formerly were famous for black teas, now produce nothing but green. At Canton, green and black teas are made from the _Thea bohea_ at the pleasure of the manufacturer, and according to demand. When the plants arrive from the farms fresh and cool, they dry of a bright-green colour; but if they are delayed in their transit, or remain in a confined state for too long a period, they become heated, from a species of spontaneous fermentation; and when loosened and spread open, emit vapours, and are sensibly warm to the hand. When such plants are dried, the whole of the green colour is found to have been destroyed, and a red-brown, and sometimes a blackish-brown result is obtained. 'I had also noticed,' says Mr Warrington, in a paper read by him before the Chemical Society, 'that a clear infusion of such leaves, evaporated carefully to dryness, was not all undissolved by water, but left a quantity of brown oxidised extractive matter, to which the denomination _apothem_ has been applied by some chemists; a similar result is obtained by the evaporation of an infusion of black tea. The same action takes place by the exposure of the infusions of many vegetable substances to the oxidising influence of the atmosphere; they become darkened on the surface, and this gradually spreads through the solution, and on evaporation, the same oxidised extractive matter will remain insoluble in water. Again, I had found that the green teas, when wetted and redried, with exposure to the air, were nearly as dark in colour as the ordinary black teas. From these observations, therefore, I was induced to believe, that the peculiar characters and chemical differences which distinguish black tea from green, were to be