EVOLUTION AND DISSOLUTION 



twenty times the volume when free which they 

 have when combined ; and it is further illus- 

 trated by the fact that dead organisms, from 

 which all supply of molecular motion from with- 

 out is artificially cut off, are not decomposed. 

 It is thus that animal remains are preserved for 

 ages in blown sand and in peat-moss. And it is 

 thus that the carcases of primeval mammoths, 

 intact even to the bulbs of the eyes, are found 

 embedded in arctic ice near the mouths of Si- 

 berian rivers, just where they were slain by the 

 cold a thousand centuries ago. 1 



But the study of organic phenomena shows us 

 that our general theorem needs some further re- 

 vision. As it now stands, it runs some risk of 

 being supposed to assert that the career of any 

 composite body is at first characterized solely 

 by the concentration of matter and concomitant 

 dissipation of motion, and is at last character- 

 ized solely by the diffusion of matter and con- 

 comitant absorption of motion. A reference to 

 the history of any organism will at once show 

 that this is not the case. While the human 

 body, for example, is continually incorporating 

 with its tissues new matter in the shape of pre- 

 pared food, large portions of the matter once 

 incorporated are continually diffused in the 



1 The heads of these animals are nearly always directed 

 southward. See Lyell, Principles of Geology, ioth edition, 

 vol. i. p. 184. 



197 



