书城外语英国学生科学读本
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第86章 物质与感觉(1)

1.All the things that make up the world on which we live are composed①of some kind of stuff,or substance,or material.The name which is given to every kind of this stuff is matter,and wesay that our world is a great ball of matter.The stones on which we walk are pieces of matter;the water of the ocean is another kind of matter;and the air or atmosphere which wraps round②the whole world is yet another kind.

2.Are there any pieces of matter in this room?Yes,there are many.The walls,the windows,the desks,the tables,the chairs,the maps,and the pictures,are all pieces of matter.

3.How do you know that these pieces of matter are in the room?It is because you possess the sense of sight.This sense is confined to two small parts of the surface of your body-your eyes-and by using your eyes you can find out a great deal about matter,such as its shape,its size,and its colour.

4.But do not blind children know about matter ?Yes,indeed;for,though they cannot see,they have still the sense of touch.

①Composed,made up of.

②Wraps round,encircles;covers.

This sense is spread over all the surface of the body,but the tips of the fingers have the keenest sense of touch.Blind children can feel their way among the pieces of matter which surround them,and can tell a great deal about each piece of matter which they touch,although they cannot see it.

5.The other day I went into a room,and the moment I opened the door I knew that there had been an escape of gas from the pipe which leads to the gas-burner.I could not see the coal-gas,and I could not feel it,but I could smell it,and I knew by my sense of smell that there was some of the matter called coal-gasmixed with the air of the room.The sense of smell is confined①tothe inside of the nose.If you pinch your nose hard,you will findthat you can smell nothing.

6.If you have a money-box,can you find out whether there are any of those pieces of matter which we call coins inside it,without opening the box?Yes;you can do this easily by shaking the box:you will then hear the coins rattle,if there are any in it.The sense of hearing is confined to the two parts or organs of the body which are called the ears.

7.Here are two white powders which look and feel exactlyalike,and neither of which has any smell.How can you find out whether they are both made of the same kind of matter or not?Suppose you put a little of each powder on your tongue,so that you may taste it.Now you can tell at once that the one powder is sugar,and that the other is salt.

8.We possess the five senses called seeing,feeling,smelling,hearing,and tasting.By using these five senses we are able to find out a great deal about the stuff or matter of which this world is made.Anything that affects one or more of our five senses is called matter.Matter is anything that we can see,or feel,or smell,or hear,or taste.

①Confined,limited;kept within the bounds of.

9.Matter is not all alike.If it were,what a dreary world this would be!Different pieces of matter have different forms,colours,tastes,and smells.Some kinds of matter are soft,while others are hard;some kinds are heavy,while others are light.