Geologi/ of Herefordshire, &,x. 41 



it indiscriminately in abundant alternacies, between sand- 

 stones and limestones, and streaking through the superficial 

 soils, particularly observable in the sides of the road from 

 Gloucester to Ross. Their two colours are particularly in coin- 

 cidence with sandstone, and probably the more talcy contains 

 magnesia. 



The blue limestone, by some distinguished by the appellation 

 of mountain limestone, is very abundant. On examination I 

 find it a congeries of the cardia genius of shells ; above is usual- 

 ly found the brown, similarly composed. Above all, the crop- 

 stone a thin, shaly bordering of stone, never used in burning, 

 and very largely compounded with clay. I observe the shells 

 in the brown limestone, here and there crystallizing in circular 

 figures like fiUigree work. On what this conversion, at 

 all events partial, may depend, I do not know how to ex- 

 plain. A white limestone, is found in masses at the foot 

 of Coldwell and Symond's Gate, and at the top of those 

 hills they are burning one variety, and at the foot another. 

 Under the cropstone of these hills, I found, together with 

 H. Neele, Esq., a friend of no ordinary literary merit, a 

 very shallow but peculiar rock, very compact, but yet 

 in some degree porous, red and marked with shells. At first I 

 conceived it to be trap, but on comminution, and exposure to 

 muriatic acid, I found much carbonate of lime ; but the quan- 

 tity of sand also induces me to believe that some transition be- 

 tween sand and limestone had ensued. I have found specimens 

 of mixed limestone and sandstone like scoriae. At Coldwell, 

 a kind of dove-coloured marble has been found which will re- 

 ceive a polish, but much too slight in bulk for general use. 

 This country abounds with limestones : the magnesian must oc- 

 cur, but I have not found a very well defined specimen; a strange 

 prejudice has gone forth against it in mixing with soils : the 

 truth is, that in some it binds so firmly as to be too stiff and 

 tenacious for the purposes of agriculture ; but a gentleman of 

 considerable mineralogical talents, told me that when in some 

 part of .South Wales, he expressed his curiosity at seeing it 

 spread on the soil, and was told that it was indispensable in 

 good cultivation. In burning limestone, that which is most 



