英文科學(xué)讀本 第一冊·Lesson 26 Sugar

Lesson 26 Sugar

Sugar, like salt, is a substance we can dissolve in water, said Fred. "Salt is a mineral. It comes out of the ground. I want to tell you something about sugar tonight. But in the first place, sugar is not a mineral.

Take this cabbage leaf in your hand and squeeze it. What do you see?

My hand is wet, said Norah.

Yes, said Fred, "it is wet because you squeezed some juice out of the leaf. All plants are full of juice of some sort; we call it the sap."

Teacher showed us a picture of a great plant called the sugarcane. It grows in very hot lands far away. It has a very tall stem, but no branches; only some big broad leaves up the stem.

This sugar-cane, like all other plants, is full of sap. When it is full grown, the sap is very sweet.

Oh, I see, said Norah. "Then the sugar comes from this sweet juice."

Wait a minute, said Fred, "and you shall see."

When the men know that the canes are ready, they cut them down and saw them into short pieces. Then the pieces are crushed between heavy iron rollers.

That is to squeeze out the juice, of course, said his sister.

Right, said Fred.

Now, little sister, he added, "tell me what happens when we boil brine?"

Why, the water boils away, said Norah, "and leaves the salt behind."

Right again, said Fred. "You will see how they get the sugar into the sweet juice."

They boil the juice in large pans. The water in the juice boils away, and the sugar is left behind. As it cools the sugar forms into solid grains.

You must not forget, said Willie, "that this is only raw or moist sugar. It has to be made into white loaf sugar."

They leave this moist sugar to drain, added Fred, "and what do you think we call the part that drains away from it. It is the treacle we eat on our bread."

SUMMARY

Sugar comes from the sweet juice of the sugar-cane, a great plant which grows in hot lands far away. When the canes are ripe, they are cut down, and the sweet juice is squeezed out of them. Men boil the juice in great pans, and as the water of the juice boils away, the sugar is left behind. The thick, brown part of the juice is treacle.