NOTES. 459 



ceous stone, clay, and coal, had an uniform arrangement concentric to the centre 

 of the earth. 



Beneath all these we have No. 5, a Limestone formation, 50 yards thick, and 

 similar to No. 3; that is to say, laminated, containing minerals and figured stones. 

 It is productive of marble ; it abounds with entrochi and marine exuviae : it was 

 thence at one time the bed of a primaeval ocean. 



No. 6 is Toadstone, 40 yards deep, and similar to No. 4, but yet more solid, 

 showing that the fluid metal was much more intensely heated and combined than 

 No. 4. 



No. 7, Limestone, very white, 60 yards deep ; laminated like No. 3 and 5, and 

 like them it contains minerals and figured stones, and was either a continuation of 

 Nos. 3 and 5, the entire mass having been split at different depths by the expansive 

 power of the boiling lara. 



No. 8, is Toadstone, 22 yards deep, similar to No. 6, but yet more solid. 



No. 9, Limestone, resembling Nos. 3, 5, and 7. 



To this enumeration of the Derbyshire strata we must now add six other strata f 

 too minute to be expressed in the same scale, but which are in fact the capillary 

 strata, which we may liken to the glass plates referred to hi Problem LXXI. 

 Miners call these minute parallel strata, clays, OT way-boards : in general they are not 

 more than four, five, or six feet thick, and in some instances not more than one foot. 

 They are the channels for water, and all the springs flowing from them are warm y 

 like those at Buxton and Matlock Bath. The first stratum of clay separates Nos. 3 

 and 4 ; the second, Nos. 4 and 5; the third, Nos. 5 and 6; the fourth, Nos. 6 and 

 7 ; the fifth, Nos. 7 and 8 ; the sixth, Nos. 8 and 9 : and what is very remarkable, 

 by these clays the thickness of the other strata may be ascertained, which would 

 otherwise be difficult, as the limestone beds consist of various lamina. 



There are several circumstances illustrative of this capillary attraction, which 

 receive illustration from the diagram before us ; to these we shall now address- 

 ourselves ; and, first, it is observable that all the parallel strata basset or shoot 

 towards the surface, occasioning thereby a diversity of soil ; and as the beds or 

 layers of rock, c. contain fossil remains, we may expect to meet with shells, corals,, 

 bones, plants, trees, &c. on or near the surface. All these rocks ranged in beds or 

 layers, whether perfectly horizontal or shooting up at any angle, are called strati- 

 fied ; while abrupt masses of granite,* having none of this masonic appearance, are 

 said to be unstratified. It is obvious, from what has been observed above, that the 

 stratified parts of the globe are those in which we must look for capillary veins 

 and sheets of water. 



In the diagram before us all the strata are distinctly marked with their various 

 dislocations and fissures. The river Derwent is supposed to flow over a vast fissure, 

 R ; the letters A, A, A indicate lesser fissures ; G, G, G do the same, and all these 

 fissures are hi the limestone strata. Hence it appears that the toadstone or lava 



* Granite consists of distinct aggregations of quartz, felspar, mica, and hornblende, each in a 

 crystalline form. Felspar is of a whitish, sometimes of a reddish colour, quite opaque, aad occasion- 

 ally crystallized in a rhomboidal form ; quartz is less abundant, somewhat transparent, and of a 

 glassy appearance ; mica is dispersed throughout in small glistening plates, the colour is dark and 

 the appearance metallic ; hornblende imparts a deep green colour to rocks called greenstone and 

 basalt. 



