Five Year Other
Periods. India. Ceylon. China. Countries.
1866-70 6·62 0·00 91·44 1·94
1871-75 10·50 0·08 85·62 3·80
1876-80 18·26 0·06 80·18 1·50
1881-85 26·73 0·86 70·71 1·71
1886-90 39·66 10·96 47·07 2·32
1891-95 47·10 29·30 21·04 2·56
1896-1900 50·25 36·30 10·52 2·93
1901-03 58·45 33·28 4·74 3·53
It appears that China which formerly supplied 90 per cent. in 1866, now
contributes less than 5 per cent. of our tea. During the same period
the Indian supply has gone up from 6 to 58 per cent., and Ceylon which
only commenced to send tea in 1875 now sends the substantial proportion
of 33 per cent. of the total importation.
From the above tables it will be seen that of the yearly average of
six pounds consumed in the United Kingdom, one third of a pound comes
from China, three and a half pounds from India, and two pounds from
Ceylon. The Dutch the next largest tea-drinkers to the British consume
a pound and a half each person per annum, half of this comes from Java
and the remaining half from the United Kingdom (principally of Chinese
origin). Most of the tea drunk in Russia comes from China. In Australia
two-thirds of the tea is imported from India and Ceylon, and the rest
comes from China. In the United States more than half the tea comes
from China and the bulk of the remainder from Japan.
I now proceed to deal briefly with the constituents of tea which are
generally believed to impart to the tea infusion its special characters.
_Alkaloid._ The alkaloid which is present in tea to the extent of 3
or 4 per cent. is thought to be identical with that found in Coffee,
viz: caffeine. It has the well-known stimulant and invigorating
qualities with which the taking of tea is associated. Thus the brain is
stimulated, the intellect becomes clear; there is removal of languor
and fatigue with increased wakefulness and alertness. The following is
by a Chinese writer, who lived over 1,000 years ago and he writes so
well, and so much to the point, that we must not quarrel with him if he
has omitted to give us the reverse aspect of the question.
It tempers the spirits, and harmonises the mind,
Dispels lassitude, and relieves fatigue,
Awakens thought, and prevents drowsiness,
Lightens or refreshes the body, and clears the perceptive faculties.
We shall also forgive Cowper’s strong prepossession in favour of tea
when we call to mind the cosy, comfortable picture which he describes:
And while the bubbling and loud hissing urn,
Throws up a steamy column, and the cups
That cheer but not inebriate, wait on each
So let us welcome peaceful evening in.
I suppose that this verse has been as much quoted as anything in our
language, and the homely picture of the evening meal has done much to
wean the English people from stronger drinks.
The following article from the _Lancet_ of 1863 presents all the
arguments, and very important arguments they are and very well stated
which can be placed to the credit of tea-drinking:--
“It has a strange influence over mood--a strange power of changing
the look of things, and changing it for the better: so that we can
believe and hope, and do under the influence of tea, what we should
otherwise give up in discouragement and despair,--feelings under the
influence of which tissues wear rapidly. In the language of the poor,
who in London we are told spend one-eight of their income in buying
tea, it produces a feeling of comfort. Neither the philosopher nor
the philanthropist will despise this property of tea, this power of
conferring comfort, or removing _ennui_, of promoting those happier
feelings of our nature under which we can do most and bear most. There
is no denying the considerable dependence of our moods and frames upon
substances; and as moods are as important as muscles, as they affect
as largely a man’s ability for the great ends of life, we cannot
regard the cheapening of such substances, when devoid of noxious
qualities, as other than a most important benefit to the poor.”
This feeling of comfort, this power of changing the aspect of affairs,
of appealing to the happier side of our nature, in other words of
putting us at our best, is undoubtedly due to the alkaloid of tea.
Since I have been interested in the subject I have conversed with a
number of friends, and many have told me that the best time of day
to do any writing or intellectual work is after a cup of tea in the
afternoon, and I must confess to feeling more myself at this time than
at any other; but, on the other hand if no afternoon tea is taken,
this period of the day is when most people feel fagged and tired and
incapable of mental exertion. This shews the great influence exercised
by tea over our moods and feelings; and if tea is taken in moderation
this property may be of great help and a mental stimulus to us in our
daily vocation.
_Tannin._--The other important constituent of tea, viz.: tannin is
present to the extent of 10 or 20 per cent. and it is this substance
to which most of the injurious effects of tea have been attributed.
In excess tannin tends to depress the action of the digestive fluids
and ferments. It interferes with the normal activity of secretion by
constricting the blood vessels and diminishing the circulation, and
lastly it tends to combine with the nitrogenous principles of the food
rendering them insoluble and incapable of digestion. The tendency
therefore of this substance is greatly to impair digestion and it
gives rise to palpitation of the heart, headache, flatulence, loss
of appetite, constipation and other symptoms so well-known at the
out-patient departments of our general hospitals; on inquiry it is
often found that the patient is accustomed to drink large quantities
of tea, which has stood for long periods and consequently extracted
excessive amounts of tannin.
In addition to the alkaloid and tannin the older writers asserted that
tea contained a volatile oil to the extent of 0·6 to 1 per cent.,
and many of the qualities and deleterious effects of tea have been
traced to the presence of this substance. The latest experiments,
however throw some doubts on these early results. Thus in the report
of Schimmel & Co. for April, 1897, it is stated (p. 39) that “in
former years we endeavoured on several occasions to distil various
kinds of tea in order to introduce tea oil ... we have, however, in no
case succeeded in obtaining more than mere traces of oil,” and they
conclude that in the hands of the early experimenters the oil found
on distillation was due to the artificial flavouring of tea which was
common at that time. Schimmel & Co. in their Report for April, 1898
(p. 50) refer to a report of the Botanical Gardens in Buitenzorg for
1896. It appears that experiments were made on a large scale, thus
2500 kilograms of freshly fermented tea leaves were submitted to steam
distillation and 130 cubic centimetres or 0·0052 per cent. of oil was
obtained.[10] It must be remembered that this oil was only found in
freshly fermented leaves and from the minute quantity I think we may
conclude that tea oil if present has little or no connection with the
qualities and attributes of tea, or the deleterious effects to which it
may give rise.
A word or two with reference to the adulteration of tea. In former
times a good many samples and especially of green tea were faced;
this consisted in the addition of some colouring matter as Prussian
blue, turmeric, or indigo; and sometimes black tea was faced with
graphite. Another practice formerly prevalent was the addition of
various leaves having a resemblance to tea leaves; and then there was
the use of exhausted or spent leaves. All these forms of adulteration
are now happily very seldom practiced. To shew the extreme rarity of
tea adulteration in this country, in the 17 years from 1887 to 1903,
7595 samples were purchased under the Food and Drugs Acts and of these
only 23 were found to be adulterated. These figures include 15 cases
in 1898, and according to the report of the Local Government Board for
this year many were of the description known as caper tea. This is one
of the China varieties and consists of small granular masses made up
by the aid of gum and starch, and this lends itself to the addition of
sand and stones as actually happened in the cases in question. I think
that with this exception of mineral matter, tea adulteration in this
country may now be said to be practically non-existant.
We have glanced through the general effects of the important
constituents of tea. I now propose to consider the amount of harm which
can be justly attributed to this popular article of daily consumption.
The opposition to tea on the ground of injury to health is almost as
old as the introduction of tea itself. One of the earliest objectors
was Dr. Simon Pauli,[11] the Physician to the King of Denmark, in
a commentary he wrote on the abuse of tobacco and tea. He objected
on the ground that “tea is moderately heating, bitter, drying and
astringent.” He felt it incumbent on him to warn Europeans against the
abuse of tea, especially as the herb he said by no means answered the
encomiums bestowed upon it by the Chinese and Japanese. “I wish all
persons especially such as are old would obstinately reject _tea_,
which so dries the bodies of the _Chinese_ that they can hardly spit.”
Pauli was also a strong opponent of Coffee and alleged that it produced
“sterility.”
Another powerful writer on the subject was Dr. Cohausen a learned and
ingenious German physician. The works of this author were numerous and
bore evidence of the vigour of his intellect and of his application
to letters. His work entitled “Neothea,” and published in 1716, was
written to shew the folly of sending to China for tea, when we had so
many herbs to hand, just as pleasant and far more healthy. His wit for
which he was justly celebrated was not sufficiently powerful to render
the use of tea unfashionable.
Boerhaave, the great Dutch physician, and follower of Hippocrates and
Sydenham had an objection to tea, but not so much to the herb itself
as to the practice of drinking of hot liquids. He refers to those
persons who “weaken their bodies with perpetual drinking of aqueous
liquors; such is the very bad custom which prevails amongst the Dutch,
who indulge themselves in a sedentary life, and all day long use those
Asiatic drinks made of the berries of coffee or leaves of tea.”[12]
He also attributed to these drinks certain nervous disorders. “I have
seen a great many, so enervated by drinking too freely of those liquors
(tea, coffee and the like) that they could hardly move their limbs, and
likewise several who were seized with the apoplexy and palsy from that
cause.”[13]
An early lay opponent of tea-drinking was John Wesley. He tells us that
when he first went to Oxford with an exceedingly good constitution “he
was somewhat surprised at certain symptoms of a paralytic disorder.”
His hand shook especially after breakfast, and he observed that if
he gave up tea-drinking for two or three days, the shaking ceased.
On inquiry he found that tea had the same effect on others, and
particularly on persons whose nerves were weak. This led him to lessen
the quantity and to drink weaker tea, but still for about 26 years he
was more or less subject to the same disorder. In 1746 he began to
observe that a number of people in London were similarly affected,
some suffering from the nerves with decay of bodily strength, and he
asked them if they were hard drinkers, and learnt in reply that they
drank nothing but a little tea, morning and evening. He came to the
conclusion that they suffered from the effects of tea like he had
himself. Wesley thought he should set an example and broke himself
of a practice which had lasted for 27 years. The first three days he
suffered from headache more or less all day long, and was half asleep
from morning to night; on the third day his memory failed but the
symptoms abated in the following day and his memory returned. He felt
great benefit from the abstinence, and found that his hand was as
steady at 45 as it had been at fifteen.
One of the most determined opponents of tea-drinking in the 18th
century was Jonas Hanway, the eminent philanthropist and “father”
of Sunday schools. His views may be gathered from the title of his
work.[14] Owing to the results of this beverage he said “men seem to
have lost their stature and comeliness; and women their beauty ... what
Shakespeare ascribes to the concealment of love, is _in this age_,
more frequently occasioned by the use of _tea_.... I am persuaded the
inhabitants of this island will never increase in number nor enjoy a
blooming health whilst they continue such an extravagant use of tea.”
Hanway’s exaggerations succeeded in drawing Dr. Johnson into the
controversy. The great man in a review of Hanway’s work said “he is to
expect little justice from the author of this extract, a hardened and
shameless tea-drinker who has for twenty years diluted his meals with
only the infusion of this facinating plant, whose kettle has scarcely
time to cool, who with tea amuses the evening, with tea solaces the
midnights, and with tea welcomes the morning.”[15]
We learn from Boswell that “no person ever enjoyed with more relish
the infusion of that fragrant leaf than Johnson. The quantities which
he drank of it at all hours were so great, that his nerves must have
been uncommonly strong, not to have been extremely relaxed by such an
intemperate use of it.” Boswell says that Johnson assured him he never
felt the least inconvenience from it. In a footnote to page 105 of
Boswell’s “Life” we are informed that a Mr. Parker of Henley was in
possession of a tea-pot which belonged to Dr. Johnson and held “above
two quarts.”
At the end of the eighteenth century Dr. Lettsom, a well-known
authority on the subject, published a work on the “Natural History
of the Tea Tree.” He found that amongst the less hardy and robust
complaints were ascribed to the drinking of tea “there are many who
cannot bear to drink a single dish of tea without being immediately
sick and disordered at the stomach, ... and that in irritable
constitutions it speedily excited the nerves to such a degree as to
give rise to uneasy sensations and bring on spasmodic affections.”
He also says “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.” For children he thought it decidedly harmful;
“children and very young persons in general, should as much as possible
be deterred from the use of this infusion. It weakens their stomach,
impairs the digestive powers and favours the generation of many
diseases.” On the whole however, he was not altogether opposed to the
practice in strong healthy vigorous adults, “to such it is undoubtedly
wholesome and equal at least if not preferable to any other kind of
regale now in use.” On another page we read that “if not drunk too
hot, nor in too great quantities it is perhaps preferable to any other
vegetable infusion we know.”
Quite at the end of the eighteenth century, Dr. Buchan, who was
something of a medical reformer, and had naturally observed the results
of tea-drinking thought that the ill-effects proceeded rather from the
imprudent use of it than from any bad qualities in the tea itself. In
his “Domestic Medicine” (p. 74) he says, “good tea, taken in moderate
quantity, not too strong, nor too hot, nor drank upon an empty stomach,
will seldom do harm, but if it be bad, which is often the case or
substituted in the room of solid food, it must have many ill effects.”
He observed that “females who live much on tea and other watery diet,
generally become weak, and unable to digest solid food; hence proceed
hysterics, and all their dreadful consequences.”
In the early part of the nineteenth century we have the opinion of
William Cobbett, a vigorous writer and acute observer of the habits
of the time in which he lived. In his “Advice to young men” Cobbett
remarks “Let me beseech you to resolve to free yourselves from the
slavery of the _tea_ and _coffee_ and other _slop kettle_, if unhappily
you have been bred up in such slavery. Experience has taught me that
those slops are _injurious to health_. Until I left them off (having
taken to them at the age of 26) even my habits of sobriety, moderate
eating, early rising, even these were not, until I left off the slops,
sufficient to give me that complete health which I have since had.”
The most complete but painful description I have come across of the
distressing symptoms occasionally associated with tea-drinking is
given by Dr. James Henry[16] who writes in 1830. He refers to the
case of a gentleman who commenced the use of tea of ordinary strength
at the age of 14. Shortly afterwards sleep became less sound, and he
became nervous and easily agitated about matters of small consequence.
Afterwards he suffered from uneasiness even while sleeping, also
from nightmare and palpitation of the heart. His sleep was disturbed
during the whole period of ten years; during this time he took three
cups of tea in the morning and three cups in the evening. At the age
of 24 or 25 he used tea more freely and his sleep became more and
more disturbed. He sometimes took tea twice in the same evening. The
suffering was very great; he did not fall asleep at night until two
o’clock and the agitation of mind and body was indescribable. The
pulsations of the heart were sometimes quick and faint, and sometimes
so violent that he could not lie on his left side. Sometimes the
pulsations became scarcely perceptible for several moments, at such
times the patient felt as if he were dying and if he fell asleep he
awoke with a violent start. He wished to sleep that he might avoid
the distressing sensations which he felt while awake, but feared to
do so lest his awakening should be accompanied by frightful agony.
After a time the distressing sensations were so marked especially just
before going to bed that “in the society of my family I felt myself
so agitated without any apparent cause that I was unable either to
speak or think deliberately, or even to remain in one position and
have been obliged that I might not be thought insane to rise abruptly,
hurry out of the house and take violent exercise in the open air.”
At 30 years of age he renounced tea and never suffered afterwards,
“the very first night I slept soundly and I have never had any return
either of sleeplessness or of starting or of the sensation of imminent
death, unless on the rare occasions when I have returned to the use
of tea.” Dr. Henry argued from the above case that “tea and coffee
act as a poison upon some persons” and on turning his attention to
the subject he found that such cases were far from uncommon, and
concluded that like alcohol tea may be indulged in for a series of
years without apparent ill consequences, but that sooner or later it
undermines the health, and renders life miserable. As with alcohol he
recognises two stages. The first stage was characterised by agreeable
sensations in the stomach, moderate perspiration, quickened pulse and
increased vivacity of mind and body. In the second stage there was
irregular pulse, sometimes rapid, sometimes slow and intermitting,
with palpitation and pains in the region of the heart--a vivacity
of thought and action which is quite uncontrollable by the will, a
painful insensibility to impressions of all kinds, twitchings of
the muscles, disturbed sleep, frightful startings especially in the
evening, irregular and sometimes cold perspiration, impaired appetite
and defective circulation in the extremities. He concluded “that the
immoderate use of tea and coffee produce a disease which bears a close
resemblance to the _delirium tremens_ of whisky drinkers, and which
is almost identical with the diseased state induced by the excessive
indulgence of opium.”
We now come to the opinion of the more recent authorities and a few
remarks are necessary concerning the symptoms liable to result from
excessive tea-drinking. In the _Boston Medical and Surgical Journal_
for September 10th, 1868, a writer Dr. Pratt explains the effects on
himself of 12 grains of the alkaloid of tea. After two hours there
was great physical restlessness, a very uneasy state of mind which
has been described by Lehmann as “mental anguish.” Soon after there
was marked tremulousness of the hands and arms; the hand trembled so
violently that it was impossible to write with any regularity. The
mind was excessively uncomfortable and anxious which admitted not of
the slightest rest; it was in a state of most active and persistent
thinking in spite of all attempts at forgetfulness. The severe symptoms
lasted about two hours. Dr. Pratt spoke to one of the most prominent
New England lady writers. She had tried green tea when pressed to do a
large amount of writing in a short time. Some time after taking a large
quantity of tea she felt as “if there was nothing left but her head
which furnished rapidly language or ideas of the best quality, and in
goodly quantity all night long.” The next day there was headache and
more or less prostration.
An important article on the “toxic effects of tea” was contributed by
Dr. Morton[17] in 1879. He said that the bad effects of tea tasting
were known and recognised by the tea tasters themselves and that few
could carry on the business for many years without breaking down. The
immediate effects of moderate doses were increased rapidity of pulse,
increased respiration, agreeable exhilaration of mind and body, a
feeling of contentment and placidity, and an increase of intellectual
and physical vigour with no noticeable reaction. The immediate effects
of an excessive dose, were a rapid elevation of the pulse and marked
increase of respiration; there was no period of exhilaration, but
immediate and severe headache, dimness of vision, ringing in the ears,
and dulness and confusion of ideas. Following this a severe reaction
with exhaustion of mind and body, tremulousness, nervousness and dread
of impending harm. The effects of continued doses were--continuance
of tremulousness, extreme susceptibility to outside impressions,
constipation and diminution of urine.
Dr. Morton concluded that tea--like other potent drugs--had its proper
and improper uses, in moderation it was a mild and pleasant stimulant
followed by no harmful reaction but that continued and immoderate use
led to serious symptoms including headache, giddiness, ringing in
the ears, tremulousness, nervousness, exhaustion of mind and body,
disinclination to mental and physical exertion, increased and irregular
action of the heart and also dyspepsia.
Dr. Bullard[18] of Boston made inquiry into the subject of poisoning
from excessive tea drinking and found that the prominent symptoms
were loss of appetite, dyspepsia, palpitation of the heart, headache,
nervousness and various forms of functional nervous symptoms of an
hysterical or neuralgic character; he found that usually speaking five
cups of tea a day on an average were required to produce symptoms of
tea poisoning.
A more recent investigator Dr. Wood[19] found in his practice at the
Brooklyn Central Dispensary that of 1000 consecutive cases applying
for general treatment, 100 or 10 per cent. were found to be “liberal
indulgers in tea,” and suffering from its deleterious effects; of those
100 patients:--
45 complained of headache.
20 ” persistent giddiness.
20 ” despondency.
19 ” indigestion.
19 ” palpitation of the heart.
15 ” sleeplessness.
Dr. Wood found that when tea had been used for a considerable period
in excess, the symptoms were giddiness, mental confusion, palpitation
of the heart, restlessness, sleeplessness, hallucinations, nightmare,
nausea, neuralgia, with prostration and anxiety. In three of Dr. Wood’s
cases there was a tendency to suicide.
Mr. Jonathan Hutchinson, a great authority thinks that it is only the
abuse of tea which is attended with serious consequences. “For my own
part I have not the least hesitation in recording the conviction that
the development of the tea trade has been in the past and will be in
the future a most important aid to the progress of civilisation. Nor
do I believe that it will be attended by any serious drawbracks.”[20]
But he sounds a note of caution when he says “there can be no doubt
whatever that the injudicious use of tea may produce not only alarming
attacks of disturbance of the heart, but seriously impair the
digestion, and enfeeble the nervous system.”
Sir Andrew Clark, who gave much consideration to the subject, in
a lecture delivered at the London Hospital said, “I may remark
incidentally that it has always been a matter of surprise to me how
it is that we English people do not suffer more than we do from our
indulgence in tea, especially tea prepared as it usually is, and taken
after a prolonged fast early in the morning. It is a great and powerful
disturber of the nervous system, and no one who has any regard for
his or her nervous system would take it in that way. Its immediate
effect may be all that can be desired. It relieves the _malaise_ which
is in itself a sign of warning, and it thus enables the consumer to
disregard it. Beware gentlemen, of thus sitting on a safety-valve.
Nature provides a warning in most cases of impending disaster, and if
you wilfully disregard or stifle them, you do so at your peril. This
pernicious habit of taking strong tea after a night’s fast, repeated
day after day, week after week, year after year, leaves its stamp on
the nervous organism of the individual, and this stamp is handed down,
in part at any rate, to the generation that follows.”[21]
Sir Lauder Brunton[22] who has also given much study to the question
made some remarks in his Lettsomian Lectures on the “Disorders of
Digestion.” He said that tea was very apt to cause a feeling of
acidity and flatulence. Sometimes the acidity comes on so soon after
the tea taken that it is difficult to assign any other cause for
it than an alteration in sensibility of the mucous membrane of the
stomach or œsophagus. The effect of tannin he said was to interfere
very considerably with the digestion of fresh meat, and there were
many people in whom tea taken along with fresh meat will upset the
digestion. It did not interfere with the digestion of dried meat such
as ham or tongue, the fibres of these have already become shrunk or
toughened in the process of curing. He thought that tea at breakfast
was not so apt to cause indigestion, but that tea in the afternoon two
or three hours after lunch would sometimes bring on acidity almost
immediately. A part of the mischief wrought by tea in the lower classes
was due to allowing it to infuse for a long time so that a large
quantity of tannin was extracted. Another reason was that the poor
were accustomed to drink tea very hot. Heat was a powerful stimulant
of the heart, and a cup of hot tea was therefore much more stimulating
and refreshing than a cold one. The practice, however, of sipping the
tea almost boiling was apt to bring on a condition of gastric catarrh.
Sir B. W. Richardson was probably more opposed to the practice of
tea-drinking than any of our leading modern physicians and as one of
the most distinguished medical reformers of recent times his opinion is
entitled to carry much weight.
“The common beverage tea,” he says, “is often a cause of serious
derangement of health, if not of actual disease. The symptoms of
disturbance occur when even the best kind of tea is taken in excess,
and almost inevitably from the mixture called ‘green tea’ when that
is taken even in moderate quantity.... Tea first quickens, and then
reduces the circulation which is the action of a stimulant. But tea
does more than this; it contains tannin, and is therefore styptic or
astringent in its action from which circumstance it is apt in many
persons to produce constipation, and interfere with the function of the
liver. In some persons this astringent effect of tea is very bad. It
gives rise to a continued indigestion, and what is called biliousness.
The most important agent in tea, however, is the organic alkaloid,
theine. The alkaloid exercises a special influence on the nervous
system, which, when carried to a considerable extent, is temporarily
at least if not permanently injurious. At first the alkaloid seems to
excite the nervous system, to produce a pleasant sensation and to keep
the mind agreeably enlivened and active. The effect is followed by
depression, sinking sensation at the stomach, flatulency, unsteadiness
with feebleness of muscular power, and not infrequently a lowness of
spirits, amounting almost to hypochondriacal despondency. Poor people
meet the craving for natural food by taking large quantities of tea.
A strong craving for it is engendered which leads to the taking of
tea at almost every meal, greatly to the injury of health. Poor women
in the factory and cotton districts become actual sufferers from this
cause. They are rendered anæmic, nervous, hysterical, and physically
feeble. In the better classes of society similar if not such severe
injury is effected by tea in those who indulge in it many times a
day, and especially in those who indulge in what is called afternoon
tea.... The afternoon tea or drum causes dyspepsia, flatulency, nervous
depression and low spirits, for relieving which not a few persons have
recourse to alcoholic stimulation.... Tea taken late in the evening,
except immediately after a moderate meal, interferes with the sleep
of most persons by causing indigestion, with flatulency, and sense of
oppression. Some are kept awake entirely by the action of the tea on
the nervous system; others get off to sleep, but are troubled with
dreams, restlessness, and muscular startings. In a few incubus or
nightmare is a painful symptom induced by tea.” In old people however,
Sir Benjamin Richardson had not noticed such serious results “as
persons advance in life the bad effects of tea sometimes pass away or
are greatly modified.” But for the generality of people Sir Benjamin
certainly felt very strongly about the matter for elsewhere he says “it
causes in a large number of persons a long and severe and even painful
sadness, there are many who never know a day of felicity owing to this
one destroying cause.”[23]
Having generally reviewed the question of injury to health I now come
to our own experiments. I first made inquiry into the strength of tea,
as commonly consumed, and found that the usual quantity of black tea
added was about eight grammes to the 600 cubic centimetres of boiling
water. I next approached two well-known firms who kindly supplied me
with samples of pure unmixed Indian, Ceylon and China teas.
Eight grammes of each sample were weighed out and were then infused
in a tea-pot for five minutes with 600 cubic centimetres of boiling
distilled water. At the end of five minutes the infusion was poured off
and analysed for the percentage of extract, alkaloid, and tannin, and
the following tables show figures for the Indian, Ceylon and China teas
respectively.