134 EXPLOITATION OF PLANTS 
country. In other countries, however, an important 
place is held by other varieties of tea, the chief being 
green teas, oolongs, brick teas, and the unique Leppet 
tea. In the space available the manufacture of these 
teas can be referred to but briefly. 
Green teas.—Black and green teas were known in this 
country long before any attempt was made to establish 
the relationship between them. Misled by informa- 
tion supplied with botanical specimens from China, the 
botanist Hill, in 1759, explained the two products as 
being derived from different varieties of the tea plant,1 
viz. Thea 1 Rohea, yielding black (‘‘ Bohea”’) tea; and 
T. viridis, yielding green tea (5). Hill’s explanation 
held place for nearly a century, until it was finally 
disposed of by another botanist, Fortune, who in 
1847 described the manufacture of the two teas, as 
witnessed by him in China, as from one and the same 
variety of plant. Curiously enough, the true explana- 
tion had been previously published by Bontius (1631) 
and Lettsom (1799), but their accounts had been 
overlooked. 
As is well known, the differences between black and 
green teas result solely from differences in methods of 
manufacture. Whereas in the case of black tea, every- 
thing is done to promote enzyme action (fermentation) 
up to a certain point, in the manufacture of green tea 
the essential feature is the prevention of fermentation 
by the destruction of the enzyme as soon as possible 
after plucking the leaf. In China and Japan (where 
most of the green tea is made) the method employed is 
1 The tea plant was originally described by Linnzus in 1737 under 
the name of Thea sinensis. 
