4O The Cause of Life and Motion 



to a system of crystalline forces, pervading all 

 space where there is life or motion. These 

 forces can act directly only on minute particles 

 or atoms. Hence, in the muscular action of a 

 man, the movement may be traced by successive 

 stages from the extended action of the limb to 

 the more restricted and tense action of the 

 muscles, from the muscles to the still more re- 

 stricted and energetic action of the fibres, and 

 so on from the greater to the lesser organisms, 

 until finally we reach the molecules where my- 

 riads of atoms are acting with incessant energy 

 within hardly conceivable spaces. The greatest 

 muscular action of a man, is the measure of the 

 energy of the forces on those atoms from which 

 the action is derived. 



The earth is, no doubt, controlled in its move, 

 ment by the action of the forces on the elements 

 of the atmosphere. And it is extremely doubt- 

 ful whether any dense mass whatever, floating in 

 space, could be maintained in a systematic 

 movement, without either being surrounded by 

 an atmosphere or without having an atmosphere 

 contained within it. 



In all material actions we find the greater 

 movements derived from the more restricted 

 ones. Thus in a large tidal wave as caused by 

 an earthquake, we find that it is developed by a 

 series of unusually energetic small waves, or if 

 developed at once from a sudden upheaval then 



