(Infusion of 8 grammes with 600 cc. of boiling distilled water for 5
min.)
Proportion
of Tannin
No. Description Retail Per cent. Per cent. Per cent. corresponding
and District. Price Extract. Alkaloid. Tannin. to 2·8
per lb. per cent.
Alkaloid.
1 “China” Tea 2/2 20·20 2·51 4·85 5·41
2 Ordinary Black 2/2 25·60 2·04 9·03 12·39
Tea
3 “China” Tea 2/0 20·06 2·15 3·02 3·93
4 Ordinary Black 2/0 27·90 2·69 9·74 10·13
Tea
5 “Russian” Tea 2/6 23·50 2·30 5·36 6·52
6 Ordinary Black 2/8 24·60 3·02 6·03 5·59
Tea
7 “China” Tea 2/4 24·50 2·22 5·85 7·37
8 Ordinary Black 2/2 28·31 2·72 8·44 8·69
Tea
It will be observed that the China teas exhibited a fairly low
proportion of tannin. The numbers for ordinary black tea in two of
the Companies’ samples were, however, considerable. This points to
the advisability of teas being analysed before being placed upon
the market, and this is a reform much needed in the interest of the
public. The tea should be examined for the amount of the alkaloid,
and also the tannin extracted by infusion, and the price based on the
proportion of the essential ingredient, viz: the alkaloid and if it
is desired to place the matter on any sort of scientific basis, the
public should in each case be informed of the weight of tea required
to be used with boiling water (this being regulated by the quantity
of the alkaloid), and at the same time an indication should be given
of the proportion of tannin liable to be extracted in a standard
infusion. My general recommendations from the foregoing experiments,
and also from the experience of the various authorities are that if tea
is to be no longer a source of injury to health we should drink much
less, and infuse for a briefer period. The dealers also should more
frequently submit samples for analysis as in the case of other foods
and drinks; thus when we _do_ drink tea we should be in a position to
avoid those varieties which are especially harmful; and there is no
doubt that if these recommendations are carried out we shall be saved
from a number of distressing complaints which, although very rarely
fatal, have in the past occasioned much ill health, and have been a
source of discomfort and misery both of mind and body to thousands who
might otherwise have enjoyed the comfort to be derived from a carefully
regulated use of the infusion of the leaves of the tea plant.