IN THE ANIMAL ORGANISM. 245 



given time is equal to the sum of force necessary, 

 during the same time, to produce the voluntary and 

 involuntary motions ; that is, all the force which 

 the heart, intestines, &c., require for their motions 

 is lost to the voluntary motions. 



The amount of azotised food necessary to restore 

 the equilibrium between waste and supply is directly 

 proportional to the amount of tissues metamor- 

 phosed. 



The amount of living matter, which in the body 

 loses the condition of life, is, in equal temperatures, 

 directly proportional to the mechanical effects pro- 

 duced in a given time. 



The amount of tissue metamorphosed in a given 

 time may be measured by the quantity of nitrogen 

 in the urine. 



The sum of the mechanical effects produced in 

 two individuals, in the same temperature, is propor- 

 tional to the amount of nitrogen in their urine ; 

 whether the mechanical force has been employed in 

 voluntary or involuntary motions, whether it has 

 been consumed by the limbs or by the heart and 

 other viscera. 



That condition of the body which is called health 

 includes the conception of an equilibrium among 

 all the causes of waste and of supply ; and thus 

 animal life is recognized as the mutual action of 

 both ; and appears as an alternating destruction and 

 restoration of the state of equilibrium. 



In regard to its absolute amount, the waste and 



