CHAPTER III. 



THE TRANSFORMATION OF FORCES IN BIOLOGY. 



IN its incessant efforts to conquer scientific truth, humanity has 

 proceeded as it did in its mythological conceptions. As the 

 numerous gods of polytheism have little by little given place to 

 monotheism and pantheism, so observation has shown that 

 the physical forces formerly imagined and invoked to explain the 

 universe have undergone incessant transformations, and were 

 only, correctly speaking, diverse manifestations of a single force. 

 We think that scientific language would gain much by finally 

 banishing this word force, which expresses a conception alto- 

 gether metaphysical of an unknown something lurking behind 

 the material elements, and controlling them as a horseman guides 

 his horse. In truth there are in the world only matter and 

 movement, or rather, as movement is only an act of matter, there 

 is only matter in movement. When we say, for example, that 

 heat is transformed into electricity, we are simply understood to 

 say that the atomic vibration called calorific changes its mode 

 and becomes the vibration which we call electric. When a body, 

 falling freely through space, is abruptly arrested in its fall by 

 an obstacle, and immediately grows warm in proportion to the 

 rapidity of its fall, it is not a force, called weight, which is 

 transformed into another force called heat ; it is the movement 

 of totality of the falling body which is changed into a special 

 vibratory movement of the molecules of this body, <fcc., <fec. Ail 



