ERRATA. 
P. 76, line 4, for derivation read derivatives. 
P. 89, line 26, for petroleum, ether read petroleum-ether. 
P. 1 1 3, line 31 ,for Harsten read Hartsen. 
P. 115, line 16, for Conellein read Bonellein. 
P. 388, line Doulist raz</Douliot. 
P. 428, line 22, for heliotropic read geotropic. 
