OF FOSSILS. 



3eAroycd or carried off, a nucleus will be form- 

 ed in the cavity, dcfcribing its external fca- 

 :ures. 



$ civ. Remaining ItnprrJ/ions of organic Bodies. 



IN any foft fubflancc, imprefllons are left by 

 rockles, fnails, infects, fiflics, and other fmall a- 

 limals of the firmer kind, cither of their extcr- 

 lal furfacc, their bones, or Ikelctons. 



cv. OJIcocolla* 



Ix particular foils, living roots arc by degrees 

 :overed with ib hard a cntll, as to prevent the 

 ibforption of the necellary juices. \Vlien a ve- 

 getable attracls nioillurc every \vhcrc in the 

 icighhourliood of its root, the fubtile, calcarc- 

 >us, argillaceous, filiceous, and even oclircous 

 nolecules, that accompany ir, produce this ef- 

 cd. The fluid in which they were borne being 

 iblbrbcd by the rocts, they fix thcmfelvcs on 

 .he furfacc, and there forming a covering impcr- 

 ,'ious to water, tiie roots decay, putrefy, and 

 cave this crufl, which is commonly culled oflco* 



cvi. Incrjijlated organic Bodies. 



WATERS loaded with earthy particles fre- 



quently cover with a cruft, reeds, fmall bran- 



R ^ ches, 



