PREFACE. 



matter recently buried in the earth, and that which 

 has acquired a genuine fossil character Such line 

 will depend, perhaps, on putrefaction, to which 

 even organic substances, after becoming legal deni- 

 zens of the fossil world, are evidently no longer 

 subject. V. p. 2. Note. 



2. An organic structure (e) immediately or 

 derivatively that of a plant or animal, is the essence 

 of an extraneous fossil or reliquium By this alone 

 is it characterized, or distinguished from a mineral. 



If these premises be not admitted, I do not see 

 the ground on which the separation of reliquia from 

 mineral bodies can take place. The origin of a 

 fossil cannot alone furnish the distinction sought for, 



(e) By the term structure, is here to be understood not only 

 the internal fabric, but also the external figure of the fossil. 



The structure of a fossil is either organic or inorganic. The 

 inorganic is that which arises from a mere aggregation or juxta- 

 position of particles this is called the native structure of a 

 fossil, as originating in the fossil kingdom. The organic is medi- 

 ately or immediately that of a plant or animal this is called the 

 extraneous structure, as originating from bodies not belonging to 

 the fossil kingdom. 



