IL 



THE ANIMAL AS A MACHINE AND A PRIME 

 MOTOR. 



13. The Animal as a Machine— The engineer re- 

 gards the animal system with peculiar interest, as a 

 machine of singularly complicated structure, a heat- 

 engine or other prime motor — he is not certain as to 

 its classification — of extraordinary efficiency, and as 

 the embodiment of scientific problems of the highest 

 interest and greatest obscurity. In this curious ma- 

 chine, combustible matter in the form of the grains or 

 other foods, is consumed, with resultant production of 

 carbon dioxide and other chemical compounds of 

 various degrees of oxidation, and there is thus made 

 available thermal, mechanical, and probably electrical 

 as well as vital energies, all of which energies find 

 application in the processes of animal Hfe, in the per- 

 formance of work, external and internal, and probably 

 in mental operations as well. Waste also occurs in 

 the form of heat and the rejected potential energy of 

 incomplete chemical action. 



Considering the automatic system of the animal, 

 apart from intelligence and will, it is, in the eye of the 

 engineer, a self-contained prime mover, including its 

 furnace, its mechanism of work and energy-develop- 

 ment, and possessing mechanism of transmission of 

 power peculiarly and exactly adapted to its purposes. 



37 



