书城外语英国学生科学读本
46382900000028

第28章 一块盐

1.Every day we eat some of the white powder which we call salt.Salt does our bodies good,and keeps them healthy.We eat it at dinner along with our meat.We eat it,too,with eggs,and watercress,and with many other kinds of food.The baker also puts salt in our bread.

2.But where does our white table-salt come from?In the county called Cheshire there are beds of salt far down below the ground.

3.This salt is like a reddish rock or stone,and it is called rock-salt.The red colour is caused by a little rust of iron being mixed with the salt.

4.When it rains,the rain-water soaks into the ground and dissolves some of the salt.Then the men pump up this salt water,which is called brine.

5.When this brine is boiled in big iron pans,the water goes away in steam,and leaves the salt behind in little white crystals.We can see for ourselves how this is done.

6.Let us shake up some salt in a glass of water.See how soon the salt is lost sight of.We cannot see it because it is now mixed with the water,but we can taste it.

7.Now we will boil the water in a little sauce-pan.After atime all the water changes into steam,and the bottom of the sauce-pan is covered with crystals of salt.We have got our salt back again.

8.Sea-water is salty,and people who live near the sea can get salt by filling shallow ponds with sea-water in summer,when the sun is strong.Soon the heat of the sun dries up the water,and the solid salt is left at the bottom of the pond.

9.In some places rock-salt is dug in mines,just as we dig our coal.These mines are called salt-mines.The rock-salt is first dissolved in water,and then this water is boiled,and the crystals of salt are left behind.This is to make the salt clean and white.

10.Salt is rubbed over meat and fish to keep them from going bad or rotting.Fresh meat goes bad because very tiny living things,called germs,feed on it.But these tiny germs cannot bear the salt-they cannot live in it.Meat soaked in brine or well rubbed with salt will keep good for a long time.

11.Horses and cattle like salt,and thrive best when they get plenty of it.Farmers often mix salt with their hay when they are piling it up in stacks for the winter.Sometimes they put a lump of rock-salt in their horse‘s manger,that he may lick it whenever he likes.

12.Salt springs and pools are often found in the plains of America and other countries,and wild animals will go many miles to these pools,to drink the salt water,or even to lick the ground,if the spring has run dry.

SUMMARY

Salt is got below the ground in the form of a reddish rock or stone called rock-salt.Rain dissolves some of this,and the salt water or brine is pumped up and boiled.The water goes away in steam,and the salt is left in little white crystals.Salt can also be got from sea-water.Salt taken along with food is very good for people and animals.It is also good for keeping meat and fish fresh.

【中文阅读】

1.每天,我们都会吃掉一种叫做“盐”的白色粉末。盐对身体有好处,能保持身体健康。我们在吃饭的时候,把盐跟肉一块儿吃下去,也跟鸡蛋、豆瓣菜和其他很多种食物,一块儿吃下去。面包师傅也会往我们的面包里放盐。①2.但是,我们吃的白色精盐是从哪儿来的呢?在英格兰有一个郡,叫“柴郡”(Cheshire);在柴郡,地下很深的地方,有很多盐的矿床。②3.这种盐的样子,像一种红色的石头,叫“岩盐”(rock-salt)。红色是跟盐混在一起的少量铁锈的颜色。③4.下雨的时候,雨水渗到地下,把一些盐溶解了,人们就可以把这些盐水抽出来。这种盐水叫“卤水”。④5.卤水放在大铁锅里煮的时候,水变成了蒸汽,留下的是小小的白色晶体,这就是盐。我们可以自己试试,这个过程是怎么完成的。⑤6.咱们把一些盐放到一杯水里,摇一摇,看看食盐是怎么消失的。食盐现在跟水混合到一块儿了,我们看不到,但是可以尝到。

7.现在,用小汤锅煮一下这些水。过一会儿,水就都变成了蒸汽,汤锅的底下盖满了盐的结晶。我们又重新得到了这些盐。

8.海水里面是有盐的。夏天日照很强烈的时候,住在海边的人,只要把浅浅的池子灌满海水,就能得到盐。很快,太阳的热量会烤干海水,盐就留在了池塘底部。⑥9.有些地方,岩盐是从矿里挖出来的,就像从煤矿里挖煤一样。这种矿,叫做“盐矿”。人们先把岩盐溶解在水里,然后把水烧干,留下了盐的晶体。这就让盐变得又洁白又干净。⑦10.人们把盐抹在肉和鱼上,不让肉和鱼变质腐烂。鲜肉会腐烂,是因为有一些很小的,名叫“细菌”的生物要吃肉。但这些微小的细菌受不了盐,在有盐的环境里不能生存。把肉类泡在卤水里面,或者均匀地涂上盐,就可以保存很长的时间。⑧11.牛马是很喜欢吃盐的,吃足够的盐就能长得很壮。农民在畜栏里堆上干草,给它们准备过冬的时候,经常在干草里放上盐。有时候,农民还会在马槽里放上一大块岩盐,牛马什么时候想吃,都可以舔。⑨12.美国平原上,还有其他国家,经常能找到含盐的泉水和池塘。野生动物会走上很多英里的路,来到盐池旁边喝盐水。如果泉水枯干了,这些动物可能还会舔地上的土呢!⑩译注①盐的化学成分是氯化钠,是对人类生存最重要的物质之一,也是最重要的调味料之一。有一个西方的民间故事,里面提到一个公主形容自己的父王“像盐一样珍贵”,不是没有道理的。纯净的氯化钠是透明的立方晶体,现实中的食盐一般有杂质存在,就形成了白色的晶体或晶体粉末。但是食盐吃得太多也可能会引起高血压、癌症等多种疾病,世界卫生组织建议,每人每天吃盐的量最好不要超过6克。豆瓣菜也叫西洋菜、水田芹;英语叫watercress,是一种类似生菜的蔬菜。

②中国的盐产地分布很广,从东北到台湾,从新疆到内蒙古都有产盐的地方。中国最大的盐湖是青海的察尔汗盐湖,这里有32公里的路面,就是用盐铺的!

③这是“岩盐”,其他种类的盐还包括井盐、海盐、池盐等等。

④这是“井盐”,井盐的开采是各种盐中技术含量最高的。中国在北宋时期开始开凿比较深的盐井“卓筒井”。四川省自贡市是最有名的井盐产区,被誉为中国的“盐都”。“自贡”的名字,来自当地的两口盐井,一口井的盐能够“自溢”,另一口井的盐曾经“进贡”给皇帝。1835年,自贡钻出了世界上第一口超过1000米的深井“()海井”。现代中国的井盐业已经发展成为完整的工业体系。

⑤这样加工的盐叫“原盐”,里面杂质很多,不能吃。要经过一系列精加工,才能变成能吃的食盐。

⑥这是“海盐”。全世界的海水含盐量平均是3.5%左右,其中90%是氯化钠,此外还有氯化镁、硫酸镁等等。假如真像第6课结尾说的那样,海洋里的水全部蒸发了,那么全球的海底就会铺上60米厚的盐!中国早在大约5000年前,就学会从海里提取盐了。浙江省的“海盐县”就是因为古代盐场众多而得名的。

⑦这是简单的说法。在现代工艺里,盐的清洗是一个很复杂的过程。

⑧当然,现在冷冻设备发达了,冷冻就变成了肉类的主要保存手段。

⑨现在有专门生产的供牛马舔的盐,一般做成砖形的大块,学名叫“畜牧盐舔块”。

⑩这里出产的盐就是“池盐”。中国最有名的池盐产地是山西运城的盐池,已经开采了2000多年。

THE FLY