542 DOMAIN VI. CARBONACEOUS. 



forms carbonates : and that widely extend- 

 ed substance called limestone, which is 

 often primeval, is a carbonate of lime. 



Carbon itself not only appears in the 

 purest state in the diamond ; but forms 

 the preponderant part, sometimes even 90 

 in 100 of the substances now under view, 

 and which have therefore been called car- 

 bonaceous. They not only enter into the 

 composition of rocks, and some even of the 

 primitive, but form rocks themselves, as 

 coal has been found in masses of 80 or 90 

 feet in thickness. The trivial name of sea- 

 coal, arising from its importation at Lon- 

 don, might therefore well be exchanged for 

 that of rock-coal, as we say rock-salt. 

 Some might, perhaps, prefer the German 

 Bergarts. appellation of bergarts, implying sub- 

 stances of whatever kind which enter into 

 the composition of mountains ; or the 

 Geostromes. Greek geostromes, proposed by Patrin, to 

 denote the strata of the earth. But as the 

 conchitic beds of limestone, sometimes 

 more recent than coal itself, though often 

 itn thin strata, universally assume the name 



