. III. DIST. CHAR. Substance. 139 



* * * Sulphates. 

 Gypsum. 



Compact. Kirw. p. 118. It has been observed, 

 rarely contains extraneous fossils, but it is 

 to be doubted if it ever really constitutes 

 their substance. 



Selenite. James, p. 567. We have found it 

 crystallized in the cavities of shells, which 

 were imbedded in shale, over the limestone 

 strata of Derbyshire. 



BARYTIC ORDER. 



The native earths and stones of this order are but 

 few. The only one, which has as yet been noticed 

 under an extraneous form, is a sulphate, namely, 

 Baroselenite. 



Compact. Kirw. p. 138. This, it has been as- 

 serted, frequently constitutes the stony matter 

 of petrifactions. In Derbyshire both the 

 compact, foliated, and stirated varieties of 

 Baroselenite, are common ; but we have ne- 

 ver, as yet, been fortunate enough to discover 

 any of these substances in the state now un- 

 der consideration. 



ARGILLACEOUS ORDER. 



* ^Earths and Clays. 

 Tripoli, 



Rottenstone. Cariosus. Gmel. Nat. T. 3. p. 

 146. Tripoli. Kirw. p. 203. F. An. We 

 possess specimens of this stone constituting; 



