178 GEOLOGY. 



seas of but little depth ; numerous and very wide lakes and 

 rivers ; a gigantic vegetation of ferns and other acotyledonous 

 plants ; at a later period monocotyledonous ones ; formation 

 of coal and lignites ; plu tonic eruptions, without scorified lava; 

 metalliferous injections in veins ; internal effusions between 

 the strata ; atmosphere rendered less thick, in consequence of 

 the cooling of certain volatilizable matters, which are precipi- 

 tated upon the earth, such as mercury, zinc, lead, sulphur 

 and bitumen. 



EARTHS FORMED DURING THE SECOND EPOCH, 



EARTH OF TRANSITION FORMED UNDER THE INFLUENCE OF FIRE AND 



WATER. 

 SCHIST. 



Rocks arranged in laminae, or dividing easily in flags, like 

 slates. The schists of Angiers present impressions of very 

 simple animals, belonging to the class of Crustacea, but en- 

 tirely different from all those known at present. In these 

 strata we meet with touch-stone, oil-stone, black-lead, red- 

 lead, alum, vitriol, anthracite, numerous veins of copper, lead, 

 zinc and iron; mercury, with bitumen, is found in the upper 

 portions. 



CALX. 



Thick beds, including the greater part of the marbles with 

 mixed colours, such as the gray and black, also the small 

 granite, among others, remarkable on account of the round 

 and white spots, in the shape of stars, formed by fossil, Radi- 

 ata, called Encrinites. The most extensive iron mines are 

 found between these calcareous beds and the primary forma- 

 tion; hence also spring the greater number of the mineral 

 waters. 



COAL. FREESTONE. 



The transition freestone and pudding-stone are generally 

 sterile. They are advantageously employed in carving or 

 building. The pudding-stone sometimes forms also excellent 

 mill-stones, and the freestone good whet-stones. The pre- 

 sence of coal is announced by black rocks, and impressions 

 of vegetables resembling large Ferns. 



