May 2, 1892.] 
THE TROPICAL AGRICULTURIST. 
849 
This was written in Febrnary, 1886. We are 
now in February, 1892, and yet the general public 
seem as ignorant as ever, to judge by the current 
newspaper gup. It seems perhaps too much to ex- 
pect that even a dozen readers will change their 
opinion and their practice concerning tea and coffee. 
Let us hope for the best, however. Many people 
are of the opinion that tea and coffee, though nice, 
are naughty, and liave a vague idea that drinking 
such beverage is against the natural harbits of natural 
man. Others again swear by tea and scoff at the 
idea of any harm accruing to its votaries in what- 
ever wav and whatever quantity they drink it. Hut, 
as Sir \V. Uoberts remarks, man is now a very com. 
plox feeder; ho has departed, in the course of his 
civilisation, very widely from the monotonous uni- 
formity of diet observed in animals, in tho wild 
state. These generalised food customs of mankind 
aro not to be viewed as random ; racticos adopted to 
please tho palate or to gratify our idle or vicious 
appetites. These cnstonis must bo regarded as the 
outcome of profound instincts, which correspond 
to important wants of the human economy. 
They are the fruit of colossal experience, ac- 
cumulated by countless millions of men 
through successive generation. They have tho 
same weight and significance as other kindred facts 
of natural history, and are fitted to yield to observa- 
tion and study lessous of tho highest scientific and 
practical value. It is unnecessary to describe here 
Sir W Roberts' methods of investigation ; tliey are 
fully set forth in his volume and they are alike 
adinirablo for tho iugeuuity of tlieir conception and 
tho laborious accui-acy of their prosooution. 1 sliall 
concern myself at present only with that part of his 
researclios'^ which deals with tea, coffee and cocoa, 
merely nientioniiig that ho deals at length with wines 
and all alcoholic beverages, giving too ardent Tem- 
poranoe-wallalis many a sharp rap over the knuckles, 
none the less effective if indirect. 
Tea exerts a powerful retarding influence on salivary 
digestion, coffee and cocoa a comparatively feeble one. 
Sir W. Roberts estimates tho medimii strength of tea 
usually drunk at four to five per cent; strong tea may 
contain as mucli as seven per cent; weak tea as little 
as two per cent. Medium coffee has a strength of about 
seven per cent, and strong coffee twelve to fifteen per 
cent; cocoa, on tho other hand, is goncrally weaker, 
not more than about two per cent.; and this, ho 
thinks, may bo one reason why it is more suitable to 
persons with feeble digestions than tea or coffee. Tea 
exercises a powerful inhibitory effect on salivary diges- 
tion, and this appears to bo entirely due to tho largo 
quantity of tannin it contains. It appears that tannin 
exists in two conditions in tho tea leaf. One, the 
larger portion, is in the free state and is easily 
extracted by hot water ; but about one-fourth is 
fixed and remains undissolved in the fully exhaused 
tea leaves. Some persons have supposed tliat by 
infusing tea fora very short time— only two or three 
minutes — tlie passing of tannin into tho infusion would 
00 avoided. This is a delusion ; yon can no more have 
tea without tannin than you can have wine without 
alcohol. Tannin, in the free state, is one of tho most 
solulile substances known. If you pour hot water on 
ulittlo heap of tannin itdissolves like so mncli pounded 
sugar. Tea infused for two minutes was not found 
sensibly inferior in its retarding power on sali- 
vary digestion to tea infused for thirty minutes. One 
goutloman of my acquaintance (says Kir W. Roberta) 
ill ilia liorror of tannin, was in the habit of preparing 
his tea by placing tho dry loaves on a paper filter and 
simply pouring on tho boiling water. In this way he 
thought to avoid tho presence of tannin in his tea. 
Rut if you try tho experiment, and allow the proiluot, 
as it runs tiirough tlie filter, to fall into a solution 
pf per-cliloride of iron, you will find that an intense 
inky black coloration is produced, showing that 
tannin has come through in abundance. 
. In order to diiiiiiiish as far as possible tho retard- 
ing influence of tea on salivary digestion, it should 
ho made weak, and used sparingly, audit should uot 
he taken with but afUr^ the meal. There is another 
moans, mentioned by Sir W. Roberts of obviating 
Wu lelotdiug effect oI tea ou digostieu, aud com. 
meiiced by him to tho dyspeptic; it is to add a 
'pinch of bicarbonate of soda to the toa when it is 
being infused in the tea-pot. He found that ten 
grains of “oda added to an ounce of dry tea 
almost entirely removes this retarding influence. The 
infusion thus made is darker than usual, but tho fla- 
vour is not sensibly altered, nor is the infusion ren- 
dered akialine, for tea influsion is naturally slightly 
acid, and tho soda, in the proportion inontionod, only 
just neutralises this acidity. It is a very general 
practice, I believe, at- home, to add a pinch of soda to 
the tea, but not on account of neutralising the acidity, 
I am afraid, but to “ soften " hard water. In other 
words, to precipitate excess of lime held in solution 
by the “hard” water, I make it a rule now to add the 
pinch of soda required, and I cannot perceive the 
slightest difference in the flavour of the tea. Taking 
my tea without milk or sugar, as I am in tho habit of 
doing, I stand a better chance of detecting any un- 
usual flavour than if 1 drank it in tho usual way. My 
readers, however can readily judge for thomsolves. 
tloffeo, unless taken in a very large quantity, has very 
little retarding effect on salivary digestion ; this is 
explained by the fact that tho tannin of tea is replaced 
ill coffee by a substance called caffeo-tannic acid, 
tiocoa resembles coffee, and has but little or no effect 
on salivary digestion ; tho use of coffee or cocoa is 
thoreforo preft^rable to that of tea. foi* poriiona of feeble 
uigoHtioQ. Thrtri far on .salivary digestion ; wo now turn 
to !^fom'ich digostiou, which is a vorj diherent thiiiK 
Tea and coffee both exorcise a remarkable retard- 
ing effect on stomacli digestion. There was no 
appreciable difference in tho two beverages if they 
wore of equal strength, but as coffee is usually 
made of greater poreontago strength than toa, its 
effect must ordinarily bo greater. Cocoa, also, had 
much the same effect if used of the same strength 
as ton or coffee, but when of the strength as ordi- 
narily employed, its effect was inconsiderable. Strong 
coffee— nei'r— hud a very powerful retarding 
effect, and persons of weak digestion should avoid the 
customary cup of black coffee after dinner. A good 
dual has been said and is being said of the injurious 
effects on gastric digestion of tannin contained in 
tea. It has boon alleged that meat fibre is hardened 
by toa, and that tho coats of the stomach aro liable 
to be injured by ,this beverage. Those views aro 
entirely theoretical. For people of strong digestion, 
the use of toa as a beverage is, when taken in modera- 
tion, of great benefit, at least so argues Sir \V. Roberts. 
This also applies to coffee and cocoa. They serve ho 
maintains, the purpose of wholesomely slowing' the 
otherwise too rapid digestion and absorptioii of 
copious meals. 
One thing to be borne in mind, especially by 
ladies, is that tea, if taken at the same time as 
farinaceous food (such as bread, toast, porridge, 
cakes and biscuits), is much more likely to retard 
its digestion and cause dyspepsia than if taken a 
little time after eating. It is bettor to take one’s 
five o’clock tea without the customary broad and 
butter or cake, than with it. Indeed, while there 
is little that can bo said against a cup of hot tea 
as a stimulant and restorative, when taken about 
midway between lunch and dinner, and without solid 
food, it may, on the other hand, be a fruitful cause 
of dyspepsia when accompanied at that time with 
solid food. It is also a curious fact that many 
persona with whom tea, under ordinary circum- 
stances, will agree exceedingly well, will become 
tho subjects of a tea dyspepsia if they drink this 
beverage at a time when they may be suffer- 
ing from luontal worry or emoti-'iial disturbance. 
Moreover, it is a well recognised fact that persons 
who are prone to nervous excitement of tlie circula- 
tion and palpitations of the heart, have these 
symptoms greatly aggravated if they persist in the 
use of tea or coffee as beverages. The excessive 
consiun ption of tea amongst tho women of the poorer 
classes is tho cause of much of tho so called “heart 
complaints'' among them ; tho food of these noor 
women consists largely of starchy substances (bread 
and butter chiefly) together with tea, i.e., a food no 
cessary which is one of the greatest of all retarders 
of tho digeatiou of ateroby foo^, Thu offoot " 
