APPENDIX II 293 



III. When heat is diffused by conduction, there is 

 a dissipation of mechanical energy, and perfect 

 restoration is impossible. 



IV. When radiant heat or light is absorbed, other- 

 wise than in vegetation, or in chemical action, there 

 is a dissipation of mechanical energy, and perfect 

 restoration is impossible. 



[Some mathematical work omitted here.] 



The following general conclusions are drawn from 

 the propositions stated above, and known facts with 

 reference to the mechanics of animal and vegetable 

 bodies : 



1. There is at present in the material world a 

 universal tendency to the dissipation of mechanical 

 energy. 



2. Any restoration of mechanical energy, without 

 more than an equivalent of dissipation, is impossible 

 in inanimate material processes, and is probably 

 never effected by means of organized matter, either 

 endowed with vegetable life or subjected to the will 

 of an animated creature. 



3. Within a finite period of time past, the earth 

 must have been, and within a finite period of time 

 to come the earth must again be, unfit for the habi- 

 tation of man as at present constituted, unless opera- 

 tions have been, or are to be, performed, which are 

 impossible under the laws to which the known 

 operations going on at present in the material world 

 are subject. 



