208 THE PHENOMENA OF MOTION 



produce mechanical effects, and which, when trans- 

 ferred to other bodies, communicates to them all those 

 properties, the ultimate cause of which is the chemical 

 force itself; for these bodies acquire the power of caus- 

 ing 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 me- 

 chanical effects in the animal organism, observation 

 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 intestines, do not gener- 

 ate the moving power in themselves, but receive it from 

 other quarters. 



We know with certainty that the nerves are the con- 

 ductors and propagators of mechanical effects ; we 

 know, that by means of them motion is propagated in 

 all directions. For each motion we recognise a sep- 

 arate nerve, a peculiar conductor, with the conducting 

 power of which, or with its interruption, the propaga- 

 tion of motion is affected or destroyed. 



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

 the limbs, receive the moving force which is indispen- 

 sable to their functions, to change of place, to the pro- 

 duction 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 organ cannot pro- 



