$. III. DIST. CHAR. Substance. 151 



of coral =probably this variety, as he re- 

 marks, in another place (Med. Syst. Pass. p. 

 80. ) that he possesses a specimen of it adhe- 

 rent to a fossil millepore. 

 Black. James, p. 407. F. An. We have found 

 this mineral, in Derbyshire, in the form of 



shells. 



o. 103. THE SALINE MINERAL SUBST. (substan- 

 tia miner, salina) of extraneous fossils is confined, 

 perhaps, to iron vitriol. 



Obs. Salts can scarcely be said to form the mat- 

 ter of extraneous fossils They exist in several 

 earths and stones which frequently appear under an 

 organic form, as well as in certain metallic minerals; 

 but, in these, the production, or at least the separa- 

 tion, of the saline matter in a visible state, is usually 

 preceded by the decomposition of the original stone 

 or ore, and, of course, the loss of the organic struc- 

 ture, with which it was previously impressed We 

 have observed, however, iron vitriol (James, p. 

 32. ) filling the cavities, and retaining, in part, the 

 form of shells These were in a matrix of iron py- 

 rites. Bergman remarks ( Med. de Syst. Foss. Nat. 

 p. 47. ) that animal bodies are sometimes found pre- 

 served in vitriolic waters. But the impregnating 

 matter, in these and other like conservata, is not to 

 be considered as the constituent substance of the ex- 

 traneous fossil. Shells, corals, &c. have been found, 

 it is said, sometimes in common or rock salt We 

 believe, in such instances, which are very rare, 



