422 0. Fisher — Rival Theories of Cosmogony. 



canoes, and by cooling lava. It does not seem possible that 

 molten rock can imbibe water from without, because it would 

 be driven away instead of attracted, since the superficial ten- 

 sion of a substance diminishes as the temperature rises.* The 

 writer has given his views (whatever they may be worth) upon 

 this question in his Physics of the Earth's Crustf where he 

 assumes the truth of the Nebular Hypothesis. He does not 

 hold a brief for either theory. If the above remarks prove of 

 any service in assisting in elucidating the question of the 

 greater probability of either theory, his object will be gained. 

 Astronomical considerations he leaves to astronomers, among 

 whom there does not at present appear to be unanimity of 

 opinion upon the subject. 



* Maxwell's Heat, 5th ed., p. 294. 

 f 2d ed , p. 148. 



Cambridge, England. 





