BOOK I 



FOEMATION OF THE GLOBE. 



CHAPTEE I. 



APPEARANCE OF ANIMALS AND PLANTS. 



When learned men began to occupy themselves with the 

 theory of the earth, they became divided into two very 

 clearly defined opposite parties: 



The Plutonists, who attributed the formation of the 

 crust of the globe exclusively to fire ; and 



The Neptunists, who, on the contrary, derived every- 

 thing from the action of water. 



The truth is that fire and water have had their share by 

 turns. One part of the terrestrial crust is the result of 

 ignition, the other that of the deposit from water. 



It is evident that the globe was originally a purely 

 incandescent mass. Descartes had divined this great fact, 

 and had stated that the earth Avas only a sun crusted over 

 and partially extinguished, the chilled skin of which hid 

 the central furnace from view. 



Leibnitz developed this hypothesis in his Protogrea. It 

 was afterwards successively confirmed, partly by the ob- 



