书城英文图书英国学生文学读本4册
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第21章 MATCHES

1.Before a substance can begin to burn it must be made hot.But all substances do not need the same amount of heat before they catch fire.Some need very little,others a great deal.In lighting a fire we use things that will begin to burn easily.

2.Heat can be produce.

3.The savages rubbing.When your hands feel cold,you rub them together to warm them.If you rub a flat metal button smartly on wood,you can make it hot enough to burn your hand.

4.In olden times in our own country a light was got by striking steel against flint.The force of the blow broke off little bits of steel and made them red-hot;and as these red-hot sparks fell,they were caught on a piece of half-burnt rag or tinder,which took fire very easily.

5.By the use of matches we can strike a light far more easily than our forefathers could do in the days of old,or than the savages of Africa can do now.This is because the head of the match contains a substance called phosphorus,which needs very little rubbing to make it hot enough to catch fire.

6.Phosphorus burns so easily that we cannot touch it with our fingers;the heat of the hand would make it take fire and burn us.Phosphorus is a very poisonous substance,and sometimes children have been poisoned by sucking the heads of matches.

7.You must have noticed that when a match begins to burn it bursts out into a large flame.To understand the cause of this,you must remember what was said in last lesson about "burning."When a substance burns,it is really joining with the oxygen of the air;and the more oxygen it gets,the faster it burns.For example,a splinter of wood with a red-hot tip when plunged into a bottle of oxygen gas bursts into flame and burns very rapidly.

8.But we can not very well carry about with us a bottle of oxygen to dip a match in as soon as it is lighted.So a substance which contains a great deal of oxygen is mixed with the phosphorus in the head of the match,and when this is heated by the burning phosphor us,it gives out its oxygen to make the phosphorus burn still faster.

9.This material and the phosphorus are made into a kind of paste,and the ends of the match splints are dipped into this paste,which dries and forms the head of the match.It is usually coloured blue or red.The splints are first dipped in paraffineasily.

10.Matches should always be used carefully,in case of their taking fire when we do not want them to do so.Very often a box has taken fire by being crushed,or dropped on the floor,or left too near the fire,or by children playing with it,and many fires have been caused in this way.

11.Many plans were tried to make matches less dangerous,and at last this one was found to work very well.No phosphorus is put on the match,but a little of it is mixed with other substances and put on the outside of the box.The head of the match is made of a substance which contains oxygen,and burns easily.When the match is rubbed on the phosphorus,it causes a spark,and the match takes fire.These matches are called safety matches,and they cannot be lighted by rubbing on anything but the box.

12.Matches were invented in 1829 by a teacher,afterwards Sir Isaac Holden,M.P.