Tea

Although I am not a regular tea-drinker, having long found that it acted as an impediment to sleep, I recognise the importance of discussing the national beverage. It is well, however, that tea-drinkers should know something about the peculiar properties which make tea at once so agreeable and yet so deleterious to health. Tea is a stimulant - its action on the central nervous system and the heart being due to the presence of caffeine, which is present to an average extent of about 3 per cent. According to Hutchinson, who made numerous experiments to ascertain how much caffeine infused tea contains, it was found that a cup made with 8 grammes of the leaf infused for five minutes in 300 cubic centimetres of water, contained from 3/4 grain to 1 1/5 grains, according to the variety of tea employed. Thus, a person drinking three cups of such tea may consume over 3 1/2 grains, together with 6 to 8 grains of tannin, a styptic material which exerts a hardening action on the delicate mucous membrane of the stomach and intestines, and this materially contributes to the inhibition of normal digestion.

Tea assists, too, in the creation of flatulence, and when mixed with the digestive juices and the food in process of digestion in the stomach it retards their action. A little soda put into the pot with the boiling water sometimes prevents this.

Caffeine

Caffeine, according to the British Pharmacopoeia, not only acts as a stimulant to the heart, raising the pulse and pressure of the blood, but stimulates the kidneys, and influences that part of the brain which is connected with physical functions, inducing wakefulness and mental activity. With large doses a person may become restless and noisy, with a rise of temperature, and even followed by convulsions and paralysis. While its prolonged use tends to fatigue the heart, it is perfectly true that caffeine facilitates the performance of physical work.

When on one occasion, during a period of ill-health, I was confronted with a week of public work which entailed long and laborious hours, I was supplied with small doses of caffeine, which were of great value at the time; but I was urged by the accomplished physician, by whom I was advised, to abandon the dose at once owing to the dangerous influence to which I have referred. As a medical dose of caffeine varies from 1 to 5 grains, it will be readily seen how easy it is to take it in tea, and thus to damage the constitution.

Green Tea

Green Tea contains more tannin than Black Tea, and China Tea less than Indian Tea. Good tea should not be hard or astringent. It should be made immediately the water boils, and in a warm teapot or cup. The tea should be placed in an infuser, in which it should not remain more than five minutes, when it should be withdrawn from the pot, inasmuch as while the tannin increases with each minute the flavour diminishes. The process can be carried out in another way by infusing in one teapot, and pouring the infusion into another, which has also been warmed, and thus removing it from the leaves. The caffeine in tea is practically all dissolved from the leaves when the boiling water is poured upon them.

Milk

Milk should be added to tea, if only for the purpose of neutralising some of the tannin, for it possesses this property, while, like sugar, if diminishing the flavour, it adds to its nutritive value. Tea should contain no dust, nor produce an infusion which is black or dark red in colour.