36 NERVOUS AND 



should see him begin to perspire, and warm water 

 would exude, in drops, through the finest pores of his 

 skin. 



If to these considerations we add, that decisive ex- 

 periments 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 appreciable by the thermometer, we 

 can hardly be at a loss what value we ought to attach to 

 the conclusions 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 elements of the food 

 and the oxygen of the air. The existence 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 equilibrium, 

 as vegetative life ; it is obvious that in all classes of ani- 

 mals, the latter, namely, vegetative life, prevails over 

 the former, nervous life, in the earlier stages of ex- 

 istence. 



The passage or change of matter from a state of mo- 

 tion to a state of rest, appears in an increase of the 



