英文科學讀本 第五冊·Lesson 04 Tea

Lesson 04 Tea

We can see, from all we have learned hitherto, how greatly we are indebted to the vegetable world for our daily food, said Mr. Wilson. "Of course the greater part of all the articles that appear on our tables at meal-time are in the form of eatables. I have here, however, a most important article of daily consumption, although it is not for eating, but drinking. We take it as a beverage. It is tea. Tea is so common an article in every home that it will not be necessary for me to describe it to you now. We will rather confine our attention to its peculiar properties.

Take a few grains of tea in your mouth, and taste them. They have a pleasant aroma and flavor, and if you keep them long enough in your mouth you will notice a peculiar astringent taste. We will now put some of the tea into this cup, and pour on it some boiling water from the kettle. The water at once begins to assume a straw-colored tint, then becomes brown, and the more tea there is in the cup the darker the liquid will be. We say that we have made an infusion of tea. That is, the tea has not merely colored the water, but the water has actually drawn from the tea its peculiar properties.

Take the cup of tea in your hand, and smell it, and you will at once detect the peculiar odor or aroma which you noticed in the dry tea, except that it is stronger now as an infusion. You shall taste it as soon as it is sufficiently cool, and you will notice that the infusion has the flavor of the dry tea as well as its odor. Now that we no longer want the liquid infusion, we will pour it away, and see what we have left in the cup. We have a heap of brown leaves. Each little grain of tea has uncurled and opened out, and we now see that it was nothing but a leaf rolled up.

I will select two or three of the most perfect of the leaves, and spread them out carefully on this sheet of blotting-paper, so that we may examine them at our leisure. The leaves are lance-shaped—that is, long and somewhat oval, with sharp-pointed ends. They vary in length; some leaves are two, some three, and others four inches long. They have serrated or saw-like edges—that is, the edges of the leaves present something of the appearance of the edge of a saw. I have pointed out to you similar leaves in our earlier lessons, among them being those of the rosebush, basswood, appletree, and strawberry plant. These leaves are the product of an evergreen plant, commonly known as the tea-tree, although it is scarcely correct to call it a tree. It is rather a bush or a shrub. It is never allowed to grow more than three or four feet high. It bears long pointed leaves, of a bright, deep green color, with jagged saw-like edges, and being an evergreen, the leaves are the same color at all seasons of the year. It has beautiful white flowers, with yellow stamens, and these are succeeded by the fruit, a kind of dry pod, containing three seeds.

The tea-plant is supposed by some to be a native of Bengal, but it first came to the notice of Europeans in China and Japan, where it is not only extensively cultivated, but even grows wild among the hills. It will not grow except in a warm climate, and it flourishes best on the hilly slopes, provided the soil be rich and deep. The plants are usually placed in rows about five feet apart, so as to enable the pickers to walk between them when the leaves are ready to be gathered. In its general appearance a tea-plantation is said to bear some resemblance to a garden of gooseberry or currant bushes.

Let us now leave the plant itself, while we consider the value of tea as a beverage. We all know what a refreshing effect a cup of tea has upon us when we are tired and weary. Indeed, nothing seems to do us so much good, and yet no one has, hitherto, been able to prove satisfactorily the precise action of tea on the body. It contains a volatile oil, which is supposed to act upon the nerves with a soothing, quieting effect, while at the same time it stimulates their action and produces a feeling of exhilaration, and, in addition to this, by assisting the work of respiration and perspiration, it tends to cool the body. This, however, is only the case when tea is drunk in moderate quantities, for it produces the opposite effect of sleeplessness if taken in large quantities.

In making tea, it should never be boiled, because boiling carries off the volatile oil (its most valuable constituent). The proper way is to first warm the teapot with a little hot water, then put in the tea, the quantity depending upon the number of persons who require to take it, and then pour boiling water on it. A cosey, made of some non-conducting materials, such as wool or feathers, will, by keeping the heat in, help to draw the tea quickly. Even this may become injurious, however, if used carelessly. The tea should never be allowed to stand a long time, for after a while it draws from the leaves a peculiar substance called tannin, which is very injurious to the work of digestion. In these days of tea-drinking, people should know that tea taken in excess, or badly prepared, becomes in its way as great an evil as any other abused beverage."