TERNSTRQ@MIACE. 189 
practice in the use of tea, though the infusion is then made 
stronger than it is generally drunk. 
RP er ee ae eaearne 
To obtain some idea of the extent to which the constituents 
of tea are extracted under these ordinary conditions we have 
made analyses of the infusion thus prepared, and have ascer- 
tained as a general result that the 20 per cent. of extract taken 
out by the infusion will contain about one-half of the theine 
present in the tea used. An ordinary breakfast cup of equally- 
strong tea infusion measuring about eight ounces would 
therefore contain two grains of theine or thereabouts. The 
rest of the theine is leftin the spent leaves, and it requires 
_ repeated treatment with boiling water to extract the whole 
quantity. This is no doubt one of the reasons why the. 
amount of theine in tea has been under-estimated in so many | 
instances, since experimenters have operated upon a water 
extract for its determination. In one instance we found that. 
the residual leaves of tea which had been used in the cus- 
tomary manner contained as much as 1°7 per cent. of theine, 
and in another case leaves exhausted as far as practicable by 
percolating with boiling water still contained as much as 0°13 
_ per cent. calculated on the original tea.” 
; 
2 
Commerce.—The great tea-producing country is China, 
where it is said four millions of acres of ground are devoted to 
its cultivation, and the produce annually is estimated at nearly 
_ three thousand millions of pounds. Teais also largely produced 
in Japan, Java, Assamand Ceylon. (Bentl. and Trim.) Indian 
tea, which includes that of Assam, has now become an important 
article of commerce, but is objected to by many of the natives 
_ of India on account of its being more astrigent than China tea; 
it is chiefly exported to Europe through Calcutta. The exports — 
during the last three years have been :—In 1885-6, 688 
millions of pounds; in 1886-7, 78°7 millions ; in 1887-8, 875 
millions, valued at 517 lakhs of rupees. ; 
_ The following figures shane the percentage propo rtion 0 
imported into Great Britain in 1886 and in 1887 from, iffe 
