150 III. DIST. CHAR. Substance. 



Radiated. James, p. 257- F. An. & Veg. 



Hepatic. James, p. 281. F. An. & Veg. 

 Iron pyrites sometimes constitutes the entire 

 substance of the petrifaction ; but more fre- 

 quently only covers its surface in form of a 

 metallic wash or thin film. It often forms 

 the nuclei of hollow petrifactions,, particu- 

 larly of shells It is sometimes the constitu- 

 ent of petrified wood. 



LEAD ORDER. 

 Galena. Kirw. p. 216. We have seen specimens 



of fossil wood thoroughly impregnated with 



this ore. 



QUICKSILVER ORDER. 



Cinnabar. James, p, 127, Fossil shells have been 

 found filled with native cinnabar It some- 

 times also constitutes their substance ; but spe- 

 cimens of this kind are extremely rare. 



ZINR ORDER. 



Calamine. James, p. 411. F. An. We have 

 had specimens of this substance both in the form 

 of shells and coral ; but in each instance the 

 petrifaction was probably a secondary forma- 

 tion; the calamine having, in appearance, as- 

 sumed the place of calcareous spar, previously 

 moulded in the organic form. 



Blende. 



Brown. James, p. 403. F. An. ? Bergman 

 observes that he has seen Blende in the form 



