22 THE OCEAN THE FOUNTAIN OF WATERS. 



comes co-extensive with the organic world or world of 

 life ; for every plant that grows and every animal that 

 breathes is absolutely dependent on water for its 

 life. If the air did not contain water in solution, 

 the vegetable world would quickly become a vast 

 Hortus Siccus, and the animal world be converted into 



Such a state of things would involve the destruction 

 of animated nature, and this result is averted only 

 through the agency of water. The great reservoir of 

 this life-sustaining agent is the ocean, which is at once 

 the fountain whence the waters flow, and the goal to 

 which they return and where they centre. " All the 

 rivers," says the Wise Man, " run into the sea, yet the 

 sea is not full ; unto the place from whence the rivers 

 come, thither they return again." This circulation of 

 the waters is brought about in a very simple manner, 

 by the influence of the sun, alternately raising and 

 lowering the temperature of the air. Under an in- 

 creased temperature vapour rises rapidly from any ex- 

 posed surface of water, and is greedily absorbed by the 

 air, in which it is either perfectly dissolved, when it 

 becomes invisible, or is partially condensed in cloud or 

 fog. A cloudless sky is no proof of the absence of 

 watery vapour in the air, for warm air will hold in 

 perfect solution a very considerable weight of vapour. 

 A reduction of the temperature causes the condensation 

 of the vapour, which is returned to the earth as cloud, 

 fog, dew, or rain. The force of gravity compels the 

 condensed water to seek a lower level, it collects in 

 rills, streams, rivers, which in most cases flow towards 



