248 NnttalVs Geological and Miner aloglcal Remarks. 



anthracite of Rhode-lslanr!, (which is occasionally penetra- 

 ted even by seams of asbestus,) as over (he biiuminoufe 

 coal-fields of Pittsburg and Richmond ? Why are the beds 

 of coal, at Richmond in Virginia, penetrated by veins of 



granite ? 



Lastly, why arc the same organic remains found in the 

 alluvial limestone of Carolina and Georgia, as those of the 

 Great Calcareous Platform west of the Alleghany moun- 

 tains ?* Arc, in fact, those supposed epochas of time, be- 

 lieved to have intervened between the production of strata 

 any thing more than an imaginary distinction of formations 

 really allied, and as strictly dependent on each other, as the 

 members of the same formation? The grauwacke and red 

 sand-stone, we perceive, contain organic remains ; the 

 grauwacke imperceptibly blends with the granitines, sien- 

 ites, and greenstones of the Highlands. The hornblende 

 rock and its metalliferous deposites unquestionably pass in- 

 to gneiss ; gneiss is foliated granite. Where then are we 

 to seek for permanent distinctions ? What is primitive 

 what is transition — what secondary — hut the alluvions of 

 rivers and of seas ? Of what importance is the inclination 

 of strata, as the uppermost must necessarily be inclined at 

 a decreasing angle ? Nor are examples wanting of a con- 

 formable stratification of the secondary with the oldest or the 

 primitive ;f and although the rocks referred to the primi- 

 tive formation, more frequently present vertical or highly in- 

 clined planes of stratification, yet,as]\Ir, Greenough remarks, 

 it is also true, that every rock in different parts of its course 

 exhibits planes both vertically and horizontally inclined. 



1 am, I must confess, attached to those plausible distinc- 

 tions of things which tend so importantly to facilitate inform- 

 ation and promote instruction ; yet I would not wish to 

 submit to the shackles of an imaginary system, or prostrate 

 understanding at the shrine of an ambitious theory. Na- 

 ture yet presents a wide field for contemplation; there are 

 mysteries yet unravelled — prejudices which bhnd — systems 

 which for the present impose, and which must ultimately 

 vanish before the test of truth. 



* The pentreniU of Mr. Say, orasterial fos?!! of Parkinson, is found twelve 

 or fourteen miles from Savnnnuhj in the limestone, as well as in the vicinity 

 of Huntsville in Tennessee. 



t See Dr. MacCuilock's Mineralogy of the Isle of Skv, Trans. Geolog. 

 goc. Vol. 3. pp. 50, 51- 



J Greenough's GeobgTj p. 40. 



