10 A Century of /Science 



of the thing. The writings of Buffon were prepar- 

 ing men's minds for the belief that the earth's crust 

 has witnessed many and important changes, but 

 there could be no scientific geology until further 

 progress was made in physics and chemistry. It 

 was only in 1763 that Joseph Black discovered 

 latent heat, and thus gave us a clue to what hap- 

 pens when water freezes and melts, or when it is 

 turned into steam. It was in 1786 that the pub- 

 lication of James Button's " Theory of the Earth " 

 ushered in the great battle between Neptunians 

 and Plutonists which prepared the way for scien- 

 tific geology. When the new science won its first 

 great triumph with Lyell in 1830, the philosophic 

 purport of the event was the same that was being 

 proclaimed by the progress of astronomy. Newton 

 proved that the forces which keep the planets in 

 their orbits are not strange or supernatural forces, 

 but just such as we see in operation upon this 

 earth every moment of our lives. Geologists be- 

 fore Lyell had been led to the conclusion that the 

 general aspect of the earth's surface with which 

 we are familiar is by no means its primitive or its 

 permanent aspect, but that there has been a suc- 

 cession of ages, in which the relations of land and 

 water, of mountain and plain, have varied to a 

 very considerable extent ; in which soils and cli- 



