Many, from a supposition that Tea was dried in India on copper, have
attributed its pernicious properties to this metal; but we have
already observed (Part I. § VIII.), that, if Tea were tinctured with
the least quantity of copper, it might easily be detected by chemical
experiments.
Some have attributed the injurious qualities of this fashionable
exotic upon the stomach to the sugar usually drank with the Tea; but
I have had sufficient opportunities of observing in the West Indies
the good effects of drinking freely the juice of the sugar-cane,
to obviate this objection. I have known feeble emaciated children,
afflicted with worms, tumefied abdomen, and a variety of diseases,
soon emerge from their complicated ailments, by drinking large
draughts of this sweet liquor, and become healthy and strong[84].
“While flows the juice mellifluent from the cane,
Grudge not, my friend, to let thy slaves, each morn,
But chief the sick and young, at setting day,
Themselves regale with oft-repeated draughts
Of tepid nectar, and make labour light[85].”
That there is something in the finer green Teas, that produces
effects peculiar to itself, and not to be equalled by any other
substance we know, is, I believe, admitted by all who have observed,
either what passes in themselves, or the accounts that others give
of their feelings, after a plentiful use of this liquor. Nor are
the finer kinds of bohea Teas incapable of the like influence. They
affect the nerves, produce tremblings, and such a state of body for
the time, as subjects it to be agitated by the most trifling causes,
such as shutting a door too hastily, the sudden entrance even of a
servant, and other the like causes.
I know people of both sexes, who are constantly seized with great
uneasiness, anxiety, and oppression, as often as they take a single
cup of Tea, who nevertheless, for the sake of company, drink several
cups of warm water, mixed with sugar and milk, without the same
inconvenience.
A physician, whose acquaintance I have long been favoured with, and
who, with some others, was present when the preceding experiments
were made at the college of Edinburgh, has a remarkable delicacy in
feeling the effects of a small quantity of fine Tea. If drank in the
forenoon, it affects his stomach with an uneasy sensation, which
continues for several hours, and entirely takes away his appetite
for food at dinner; though at other times, when he takes chocolate
for breakfast, he generally makes a very hearty meal at noon, and
enjoys the most perfect health. If he drink a single dish of tea in
the afternoon, it affects him in the same manner, and deprives him of
sleep for three or four hours through the succeeding night; yet he
can take a cup of warm water with sugar and milk, without the least
inconvenience.
It may be remarked that opium has nearly the same effect upon him as
Tea, but in a greater degree; for he informs me, that when he once
accidentally took a quantity of the solution of opium, it had not
the least tendency to induce sleep, but produced a very disagreeable
uneasiness at his stomach, approaching to nausea. The late celebrated
Professor Whytt[86], of Edinburgh, affords a striking example how
injurious the effects of Tea may be upon constitutions, which I shall
relate in his own words. “I once imagined Tea to be in a great
measure unjustly accused; and that it did not hurt the stomach more
than an equal quantity of warm water; but experience has since taught
me the contrary. Strong Tea drunk in any considerable quantity, in a
morning, especially if I eat little bread with it, generally makes
me fainter before dinner than if I had taken no breakfast at all; at
the same time it quickens my pulse, and often affects me with a kind
of giddiness. These bad effects of Tea are most remarkable when my
stomach is out of order.”