[ '59 I 



conftitute as if it were the kernel, and the total abCence of all 

 organic remains, induce us to think that of all others they are 

 the moft antient. Other hills or mountains confift of ftony 

 maffes, apparently homogeneous, at leaft for the greater part, 

 but feparated from each other by fifTures parallel to each other; 

 thefe are moftly of an argillaceous or calcareous nature, and 

 appear to have been formed by a gradual fubfidence from water, 

 in which they were originally fufpended. As no organic remains 

 arc found in them, they alio feem to date their origin from the 

 formation of the globe. 



From the decompofition of thefe primaeval mafles, their attri- 

 tion againft each other, the crofion of water, and various other 

 accidents, clays, fands, marles, and the component particles of 

 freeftone, fandftone, limeftone, flate, and various other fpccies of 

 ftone, have arifen. Thefe are placed over each other in alternate 

 and regular beds, parallel to each other, and being commonly mixed 

 with marine exuviae or other animal or vegetable remains, the 

 hills formed of them are evidently of a date pofterior to thofe 

 already mentioned. In thefe, and in thefe only (or in plains 

 formed of the fame materials) coal is found, and there are fcarcely 

 any of them that do not contain it. 



Hills of this fort are frequently interpofed between the 

 primaival mountains and the adjacent plains ; fometimes alfo they 

 ftand fingle, and frequently they form the eminences that border 

 rivers. It is to hills of this fort, therefore, that we muft dired 

 our refearches after coal. The thicker beds of it lie pretty deep, 



generally 



