Animal Causes. 223 



To make the point clear, it can be demonstrated 

 that the causes which generate mechanical motion in 

 a locomotive produce almost identical dual energies 

 in an animal. 



Thus, a locomotive on leaving the workshop is 

 apparently, but not actually, motionless. According 

 to Mr Herbert Spencer's definition of life (" the con- 

 tinuous adjustment of internal relations to external 

 relations ") it is, even alive ; for, by contracting and 

 expanding according to the temperature, like a ther- 

 mometer, it is constantly adjusting its internal rela- 

 tions to its external relations. Nextly, it is ever 

 pressing with all its weight (gravity) against the 

 ground. And lastly, it is a huge magnet, for, if 

 tested with a compass, all its upper surfaces attract 

 the north pole of the needle, and its lower surfaces 

 the south pole. (This is the case with all iron struc- 

 tures, even the Forth Bridge, as already said). These 

 motions, generally unobserved or ignored by scientists, 

 the locomotive possesses in virtue of its material con- 

 stitution, and it exerts them as regularly and con- 

 stantly as the ocean in its ebb and flow, or as the 

 earth in its ceaseless rotation.. In addition to this 

 natural material motion (which may be called its 

 " energy "), the locomotive is fitted up for a special 

 mode of motion (which may be called its " life ") as a 

 locomotive. This life, however, is only ephemeral, 

 characteristic of it only so long as certain inviolable 

 conditions are complied with. In other words, it 

 must be fed, or supplied with water and fuel. But 



