OF EARTH. 3 



ing and propagation of vegetables,) is the natural under-turf earth ; but 

 for a description of the rest which succeed it in strata, or layers, till we 

 arrive at the barren and impenetrable rock, I shall refer the critical 

 reader to the old geoponic authors. 



Most, or all, of these strata lying in beds one upon another, from softer 

 to harder, better to worse, usually determine in sand, gravel, stone, rock, 

 or shell; which last we frequently meet with in marshes and fenny delves, 

 and sometimes even at the foot of high mountains, and sometimes on 

 their very tops, after divers successions of different moulds, and at the 

 bottom of the profoundest pits, as in that deep perforation made at Am- 

 sterdam, in order to the building of the Stadt-house \ All which, and 

 the cause of the successions of the several strata of fossils, &c. so bedded 



» Varenius informs us, that in a well which was dug at Amsterdam to the depth of two 

 hundred and thirty-two feet, the following substances were found in succession : seven 

 feet of vegetable earth ; nine of turf ; nine of soft clay ; eight of sand ; four of earth ; ten 

 of clay ; four of earth ; ten of sand ; two of clay ; four of white sand ; five of dry earth ; 

 one of soft earth ; fourteen of gravel ; eight of clay mixed with sand ; four of gravel 



mixed with shells ; an hundred and two feet of clay, and then thirty-one feet of sand 



Mr. BufFon, in the first volume of his Natural History^ gives us still a more exact enu- 

 meration of the different beds of earth found at Marly-la- Ville, to the depth of one hundred 

 and one feet. 



Ft. In. 



1. A free reddish earth, with much vegetable mould, a very small quantity 



of vitrifiable sand, and somewhat more calcinable sand or gravel 13 0 



2. A free earth, mixed with more gravel, and a little more vitrifiable sand 2 6 



3. Earth, mixed with vitrifiable sand in a very great quantity, and which made 



but very little effervescence with aqua fortis 3 0 



4. Hard mai'ble, which made a great effervescence with aqua- fortis 2 0 



5. Very hard marly stone 4 0 



6. Marl in powder, mixed with vitrifiable sand » 5 0 



7. Very fine vitrifiable sand 1 6 



8. Earthy marl, mixed with a little vitrifiable sand 3 6 



g. Hard marl, in which was real flint 3 6 



10. Gravel, or powdered marl 1 0 



11. Eglantine, a stone of the grain and hardness of marble, and sonorous 1 6 



12. Marly gravel 1 6 



13. Marl in the form of hard stone, whose grain was very fine 1 6 



14. Marl like stone, with a grairt not so fine 1 6 



Carried over 45 0 



3 F 2 



