CHAPTER XLIII THE EXPERIMENT WITH THE BOTTLE OF COLD WATER

UNCLE PAUL had rightly said, the evening before, that clouds are nothing but fog floating high in the air instead of spreading over the earth; but he had not said what fogs are composed of and how formed. So the next day he continued his talk on clouds.

“When Mother Ambroisine hangs the clothes she has just washed on the line, what does she do it for? To dry the linen¹, to free it from the water with which it is saturated². Well, what becomes of this water, if you please?”

“It disappears, I know,” answered Jules, “but I should find it very hard to tell what becomes of it.”

“This water is dissipated in the air, where it dissolves and becomes as invisible as the air itself. When you wet a heap of dry sand, the water permeates³ it throughout and disappears. It is true that the sand then takes a different appearance: it was dry before, it is wet afterward⁴. The sand drinks the water that comes into contact with it. Air does the same: it drinks the moisture from the linen and becomes damp itself; and it drinks it so completely that all—air and water—remain as invisible as if the air held no foreign substance. Vapor⁵ is the name given to water thus made invisible, or in some sort a?rial, that is to say resembling the air; and the reduction of water to this new state is called evaporation⁶. The moisture of the linen we wish to dry evaporates; the water is dissipated in the air and thus becomes invisible vapor, which spreads in every direction at the will of the wind. The warmer it is, the quicker and more abundant the evaporation. Have you not noticed that a wet handkerchief dries very quickly in a hot sun, and loses its moisture only very slowly if the weather is cloudy and cold?”

“Mother Ambroisine is always very glad when she has a fine day for her washing,” Claire remarked.

“Remember, too, what happens after watering the garden. When, at close of a very warm day, we have to give a drink to those poor plants dying of thirst, something like this happens: The pump runs at its utmost capacity; you all make haste with your watering-pots; one goes here, another there, carrying water to the suffering plants, seed-plots, and potted flowers. Soon the garden has drunk copiously⁷. How fresh it is then, how the plants, wilted⁸ by the heat, regain⁹ vigor¹⁰ and straighten up again, as happy as ever! You could almost think you heard them whispering to one another and telling how glad they were to be watered. If it could only stay that way! But, bah! the next day the earth is dry once more and all has to be done over again. What has become of the last evening’s water? It has evaporated, dissolved into the air; and now it is perhaps traveling far away, at a great height, until, turned into a scrap¹¹ of cloud, it falls again in rain. When Jules tires himself working the pump to water the flowers, has he ever thought that the water drawn¹² from the well and spread over the ground sooner or later is dissipated in the immensities of the air to play its modest part in the formation of clouds?”

“In watering my garden,” answered Jules, “I did not think I was watering the air more than anything else. But I see now: air is the great drinker. Of the contents of a watering-pot the plants take perhaps a handful; the air drinks up the rest. And that is why we have to do it all over again every day.”

“And if you exposed a plateful of water to the sun what would finally become of it?”

“I will answer that,” Emile hastened to reply. “Little by little, the water would turn into invisible vapor and there would be nothing but the plate left.”

“What takes place at the expense of a plate of water, and of the moisture of the soil or wet linen, takes place also, on a vast scale, over the entire surface of the earth. The air is in contact with damp soil, with innumerable sheets of water, lakes, marshes¹³, streams, rivers, brooks¹⁴, above all with the sea, the immense sea, which presents thrice as much surface as the dry land. The great drinker, as Jules calls it, the air, must therefore drink to satiety¹⁵ and everywhere and always contain moisture, sometimes more, sometimes less, according to the heat.

“The air that is around us now, that invisible air in which the eye distinguishes nothing, nevertheless contains water that can be made visible. The means is very simple; all that is necessary is to cool the air a little. When you squeeze a wet sponge with the hand, you make water ooze¹⁶ out of it. Cold acts on moist air very much as the pressure of the hand on the sponge: it causes the moisture to distil¹⁷ in the form of minute drops. If Claire will go to the pump and fill a bottle with very cold water, I will show you this curious experiment.”

Claire went to the kitchen and came back with a bottle full of the coldest water possible. Her uncle took the bottle, wiped it well with his handkerchief so that no trace of moisture should remain on the outside, and put it on an equally well-wiped plate.

Now the bottle, at first perfectly¹⁸ clear, becomes covered with a kind of fog which tarnishes¹⁹ its transparency: then little drops appear, run down its sides, and fall into the plate. At the end of a quarter of an hour there was enough water accumulated in the plate to fill a thimble.

“The drops of water now running down the outside of the bottle,” Uncle Paul explained, “do not come, it is very clear, from the inside, for glass cannot be pierced by water. They come from the surrounding air, which cools off on touching²⁰ the bottle and lets its moisture distil. If the bottle were colder, if full of ice, the deposit of liquid drops would be more abundant.”

“The bottle reminds me of something of the same kind,” said Claire. “When you fill a perfectly clean glass with very cold water, the outside of the glass immediately tarnishes and looks as if badly washed.”

“That again is the surrounding air depositing its moisture on the cold side of the glass.”

“Is that invisible moisture contained in the air abundant?” asked Jules.

“The invisible vapor of the air is always a thing so subtle, so disseminated²¹, that it would take enormous volumes to make a small quantity of water. During the heat of summer, when the air holds the most vapor, it takes 60,000 liters of moist air to furnish one liter of water.”

“That is very little,” was Jules’s comment.

“It is a great deal if one thinks of the immense volume of the atmosphere,” replied his uncle, and then added:

“The experiment of the bottle teaches us two things: first, there is always invisible vapor in the air; in the second place, this vapor becomes visible and changes into fog, then into drops of water, by cooling. This return of invisible vapor to visible vapor or fog, then to a state of water, is called condensation²². Heat reduces water to invisible vapor, and cold condenses this vapor, that is to say brings it back to a liquid state or at least to the state of visible vapor or fog. We will have the rest this evening.”

1 linen   

n.亚麻布，亚麻线，亚麻制品；adj.亚麻布制的，亚麻的

参考例句：

• The worker is starching the linen.这名工人正在给亚麻布上浆。
• Fine linen and cotton fabrics were known as well as wool.精细的亚麻织品和棉织品像羊毛一样闻名遐迩。

2 saturated   

a.饱和的，充满的

参考例句：

• The continuous rain had saturated the soil. 连绵不断的雨把土地淋了个透。
• a saturated solution of sodium chloride 氯化钠饱和溶液

3 permeates   

弥漫( permeate的第三人称单数 )； 遍布； 渗入； 渗透

参考例句：

• Studies show that water vapor quickly permeates plastic packaging material. 研究证明水蒸汽能迅速渗入塑料封装材料。
• Democracy permeates the whole country. 民主主义（的思想）普及全国。

4 afterward   

adv.后来；以后

参考例句：

• Let's go to the theatre first and eat afterward. 让我们先去看戏，然后吃饭。
• Afterward,the boy became a very famous artist.后来，这男孩成为一个很有名的艺术家。

5 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

6 evaporation   

n.蒸发，消失

参考例句：

• Be careful not to lose too much liquid by evaporation.小心不要因蒸发失去太多水分。
• Our bodies can sweat,thereby losing heat by evaporation.我们的身体能出汗，由此可以蒸发散热。

7 copiously   

adv.丰富地，充裕地

参考例句：

• She leant forward and vomited copiously on the floor. 她向前一俯，哇的一声吐了一地。 来自英汉文学
• This well-organized, unified course copiously illustrated, amply cross-referenced, and fully indexed. 这条组织完善，统一的课程丰富地被说明，丰富地被相互参照和充分地被标注。 来自互联网

8 wilted   

（使）凋谢，枯萎( wilt的过去式和过去分词 )

参考例句：

• The flowers wilted in the hot sun. 花在烈日下枯萎了。
• The romance blossomed for six or seven months, and then wilted. 那罗曼史持续六七个月之后就告吹了。

9 regain   

vt.重新获得，收复，恢复

参考例句：

• He is making a bid to regain his World No.1 ranking.他正为重登世界排名第一位而努力。
• The government is desperate to regain credibility with the public.政府急于重新获取公众的信任。

10 vigor   

n.活力，精力，元气

参考例句：

• The choir sang the words out with great vigor.合唱团以极大的热情唱出了歌词。
• She didn't want to be reminded of her beauty or her former vigor.现在，她不愿人们提起她昔日的美丽和以前的精力充沛。

11 scrap   

n.碎片；废料；v.废弃，报废

参考例句：

• A man comes round regularly collecting scrap.有个男人定时来收废品。
• Sell that car for scrap.把那辆汽车当残品卖了吧。

12 drawn   

v.拖，拉，拔出；adj.憔悴的，紧张的

参考例句：

• All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
• Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。

13 marshes   

n.沼泽，湿地( marsh的名词复数 )

参考例句：

• Cows were grazing on the marshes. 牛群在湿地上吃草。
• We had to cross the marshes. 我们不得不穿过那片沼泽地。 来自《简明英汉词典》

14 brooks   

n.小溪( brook的名词复数 )

参考例句：

• Brooks gave the business when Haas caught him with his watch. 哈斯抓到偷他的手表的布鲁克斯时，狠狠地揍了他一顿。 来自《简明英汉词典》
• Ade and Brooks exchanged blows yesterday and they were severely punished today. 艾德和布鲁克斯昨天打起来了，今天他们受到严厉的惩罚。 来自《简明英汉词典》

15 satiety   

n.饱和；(市场的)充分供应

参考例句：

• There is no satiety in study.学无止境。
• Their presence in foods induces satiety at meal time.它们在食物中的存在诱导进餐时的满足感。

16 ooze   

n.软泥，渗出物；vi.渗出，泄漏；vt.慢慢渗出，流露

参考例句：

• Soon layer of oceanic ooze began to accumulate above the old hard layer.不久后海洋软泥层开始在老的硬地层上堆积。
• Drip or ooze systems are common for pot watering.滴灌和渗灌系统一般也用于盆栽灌水。

17 distil   

vt.蒸馏；提取…的精华，精选出

参考例句：

• You can distil fresh water from the sea.你可以用蒸馏法从海水中提取淡水。
• The writer managed to distil his ideas into one succinct article.作家努力把他的想法浓缩成一篇简练的文章。

18 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

19 tarnishes   

污点，瑕疵，无光泽( tarnish的名词复数 )

参考例句：

• Brass tarnishes quickly in wet weather. 天气潮湿时黄铜很快会失去光泽。
• This metal tarnishes easily. 这种金属易变色。

20 touching   

adj.动人的，使人感伤的

参考例句：

• It was a touching sight.这是一幅动人的景象。
• His letter was touching.他的信很感人。

21 disseminated   

散布，传播( disseminate的过去式和过去分词 )

参考例句：

• Their findings have been widely disseminated . 他们的研究成果已经广为传播。
• Berkovitz had contracted polio after ingesting a vaccine disseminated under federal supervision. 伯考维茨在接种了在联邦监督下分发的牛痘疫苗后传染上脊髓灰质炎。

22 condensation   

n.压缩，浓缩；凝结的水珠

参考例句：

• A cloud is a condensation of water vapour in the atmosphere.云是由大气中的水蒸气凝结成的。
• He used his sleeve to wipe the condensation off the glass.他用袖子擦掉玻璃上凝结的水珠。