CHAPTEE XLIH 



THE EXPERIMENT WITH THE BOTTLE OF COLD WATER 



UNCLE PAUL had rightly said, the evening be- 

 fore, that clouds are nothing but fog floating 

 lii-h 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 

 lias just washed on the line, what does she do it for! 

 To dry the linen, to free it from the water with 

 which it is saturated. 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 dis- 

 solves and becomes as invisible as the air itself. 

 When you wet a heap of dry sand, the water 

 permeates it throughout and disappears. It is true 

 that the sand then takes a different appearance: it 

 was dry before, it is wet afterward. 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 in- 

 visible as if the air held no foreign substance. 

 Vapor is the name given to water thus made invisi- 



192 



