CHAPTER II. 



LIFE. 



WE know and can know nothing of life in 

 the abstract that is, apart from its mani- 

 festations ; but that does not preclude us 

 from endeavouring to discover its laws by 

 the study of its phenomena, or the process 

 of its evolution by tracing its progress in 

 the races of plants and animals that suc- 

 cessively appeared on the earth. 



We know nothing in the abstract of the 

 force called gravitation, but we conclude 

 from its phenomena that there is a specific 

 force that operates according to certain un- 

 varying laws, and from these laws we can 

 predicate how matter will be affected by 

 gravitation under all known conditions. 



Nothing is known of ether, and we have 

 even no direct evidence of its existence, but 

 scientific authorities assume that there must 

 be a something which they name ether to 



