IN THE ANIMAL ORGANISM. 219 



duce mechanical effects, and which, when transferred 

 to other bodies, communicates to them all those pro- 

 perties, the ultimate cause of which is the chemical 

 force itself; for these bodies acquire the power of 

 causing decompositions and combinations, such as, 

 without a supply of force through the conductor, 

 they could not effect. 



If we employ these well-known facts as means 

 to assist us in investigating the ultimate cause of 

 the mechanical effects in the animal organism, ob- 

 servation teaches us, that the motion of the blood 

 and of the other animal fluids proceeds from distinct 

 organs, which, as in the case of the heart and in- 

 testines, do not generate the moving power in them- 

 selves, but receive it from other quarters. 



We know with certainty that the nerves are the 

 conductors and propagators of mechanical effects ; 

 we know, that by means of them motion is propa- 

 gated in all directions. For each motion we recog- 

 nize a separate nerve, a peculiar conductor, with 

 the conducting power of which, or with its interrup- 

 tion, the propagation of motion is affected or de- 

 stroyed. 



By means of the nerves all the parts of the body, 

 all the limbs, receive the moving force which is in- 

 dispensable to their functions, to change of place, 

 to the production of mechanical effects. Where 

 nerves are not found, motion does not occur. The 

 excess of force generated in one place is conducted 

 to other parts by the nerves. The force which one 



