358 FRAGMENTS OF SCIENCE 



recognizes in the material universe a constant sum of 

 power made up of items among which the most Protean 

 fluctuations are incessantly going on. It is as if the body 

 of Nature were alive, the thrill and interchange of its en- 

 ergies resembling those of an organism. The parts of the 

 "stupendous whole" shift and change, augment and di- 

 minish, appear and disappear, while the total of which 

 they are the parts remains quantitatively immutable. Im- 

 mutable, because when change occurs it is always polar 

 plus accompanies minus, gain accompanies loss, no item 

 varying in the slightest degree without an absolutely equal 

 change of some other item in the opposite direction. 



The sun warms the tropical ocean, converting a portion 

 of its liquid into vapor, which rises in the air and is recon- 

 densed on mountain heights, returning in rivers to the 

 ocean from which it came. Up to the point where con- 

 densation begins, an amount of heat exactly equivalent 

 to the molecular work of vaporization and the mechanical 

 work of lifting the vapor to the mountain- tops has disap- 

 peared from the universe. What is the gain correspond- 

 ing to this loss? It will seem when mentioned to be ex- 

 pressed in a foreign currency. The loss is a loss of heat; 

 the gain is a gain of distance, both as regards masses and 

 molecules. "Water which was formerly at the sea-level has 

 been lifted to a position from which it can fall; molecules 

 which have been locked together as a liquid are now sep- 

 arate as vapor which can recondense. After condensation 

 gravity comes into effectual play, pulling the showers 

 down upon the hills, and the rivers thus created through 

 their gorges to the sea. Every raindrop which smites the 

 mountain produces its definite amount of heat; every river 



