306 



IXDEX. 



Rocks, chemical constitutioa of, difference in, 



' gneiss, 



excess of, the cause of barrenness, 

 some of better effect than others, 

 divided into two classes, . 



20, 



40, 



44, 



146 



147, 



148, 



SKCTIO.V. 



15 



16 

 17 



18 

 19 



19 

 26, 27, 28 

 30 

 34 

 35 

 38 

 40, 43 

 48 

 290 

 . 290 

 26,28 

 26 



276 



. 149 

 170 



. 166 

 269 



. 269 



46, 50, 76 



57 



80 



133, 171 

 149, 150, 171 

 147 

 151 

 154 

 155 

 155 

 155 

 156 

 156 

 168 



45 



