THE ANIMAL AS A PRIME MOVER. 337 



could be applied in industrial operations in place of the heat engines 

 would afford inconceivable amelioration of the condition of the race, 

 and to a less but nevertheless considerable degree of his attendant 

 creatures, both by giving the power of securing the utmost possible 

 duty from our stores of latent available energy, and by prolonging the 

 life of the race by indefinitely removing the period of exhaustion of 

 those stores. 



(6) The best evidence yet secured by research seems to indicate that 

 the method of energy transformation in the vital machine is one which 

 directly transforms the potential energy of the food, as developed by 

 chemical combinations, into kinetic form, sometimes perhaps simply by 

 chemico dynamic change, sometimes by chemico-electric transforma- 

 tion; and this in turn, and possibly also the energy due to oxidation of 

 food, and, to some extent, of the muscle itself, into mechanical power, 

 into the vital energy of the automatic system, and into the form of 

 energy producing brain work. 



(7) The vital machine may produce electricity as one principal output 

 of its working processes, and probably by some direct system, without 

 intervention of either heat energy or dynamical power. 



(8) The vital machine may produce light energy in substantially 

 unadulterated form, and by some process which does not involve either 

 high temperature or the production of heat or other energies to be 

 rejected as waste. 



(9) It seems most probable, in view of what has been here collated, 

 that the vital machine is some form of chemico and electro dynamic 

 engine. 



We know that the vital machine is not thermo-dynamic in the sense 

 of being a.heat engine of any known class. We find in electricity the 

 apparently next most available form of energy for use in transforma- 

 tion into dynamic and thermal and other forms, and many accept this 

 as a provisional, a working, hypothesis. This was long ago hinted at 

 by the greatest scientific men, the greatest minds, it would perhaps be 

 fair to say, that have illuminated the history of the race. A century 

 ago Benjamin Thompson (Count Rum ford), a keen "Yankee" with 

 uncontrollable inclinations toward scientific research, showed to his 

 own satisfaction, and to the extent of proving to others its probability, 

 that the animal system constitutes a machine of higher efficiency than 

 any steam engine. 1 Joule, as long ago as 1846, working with Captain 

 iScoresby, concluded that the animal motor "more closely resembles an 

 electro -magnetic engine than a heat engine," and this is reaffirmed by 

 Tait in our own day. 2 Sir William Thomson, now Lord Kelvin, in his 

 papers of about 1850, adopts the idea of Joule, and introduces the prin- 

 ciple of Carnot, and says explicitly: "When an animal works against 

 a resisting force, there is not a conversion of heat into mechanical effect, 



1 Rumford's Essays, 1800. 



2 Tait's History of Theruio-dyuamics. 



SM 90 22 



