38 NERVOUS AND 



experiments are on record, in which animals were 

 made to respire in an unnatural position, as for 

 example, lying on the back, with the limbs tied so 

 as to preclude motion, and that the temperature of 

 their bodies was found to sink in a degree appreci- 

 able by the thermometer, we can hardly be at a 

 loss what value we ought to attach to the conclu- 

 sions drawn from such experiments as those above 

 described. 



These experiments and the conclusions deduced 

 from them, in short, are incapable of furnishing the 

 smallest support to the opinion that there exists, in 

 the animal body, any other unknown source of heat, 

 besides the mutual chemical action between the ele- 

 ments of the food and the oxygen of the air. The ex- 

 istence of the latter cannot be doubted or denied, and 

 it is amply sufficient to explain all the phenomena. 



VII. If we designate the production of force, the 

 phenomena of motion in the animal body as nervous 

 life, and the resistance, the condition of static equi- 

 librium, as vegetative life; it is obvious that in all 

 classes of animals the latter, namely, vegetative life, 

 prevails over the former, nervous life, in the earlier 

 stages of existence. 



The passage or change of matter fi*om a state of 

 motion to a state of rest aj^pears in an increase of 

 the mass, and in the supply of waste; while the 

 motion itself, or the production of force, ajipears in 

 the shape of waste of matter. 



