IN THE ANIMAL ORGANISM. 229 



if the original equilibrium is to be restored, we must 

 suppose that, during sleep, an amount of force is 

 accumulated in the form of living tissue, exactly 

 equal to that which was consumed in voluntary and 

 involuntary motion during the preceding waking 

 period. 



If the equilibrium between waste and supply of 

 matter be in the least degree disturbed, this is in- 

 stantly seen in the different amount of force avail- 

 able for mechanical purposes. 



It is further obvious, that if there should occur a 

 disproportion between the conducting power of the 

 nerves of voluntary and involuntary motion, a dif- 

 ference in the phenomena of motion themselves 

 will be perceptible, in the same proportion as the 

 one or the other is capable of propagating the 

 momentum of force, generated by the change of 

 matter. As the motions of the circulating system 

 and of the intestines increase, the power of pro- 

 ducing mechanical effects in the limbs must dimi- 

 nish in the same proportion (as in wasting fevers) ; 

 and if, in a given time, more vital force has been 

 consumed for mechanical purposes (labour, running, 

 dancing, &c.) than is properly available for the vo^- 

 luntary and involuntary motions; if force be ex- 

 pended more rapidly than the change of matter can 

 be effected in the same time ; then a part of that 

 force which is necessary for the involuntary mo- 

 tions must be expended in restoring the excess of 

 force consumed in voluntary motion. The motions 



