12 NATURAL HISTORY OF SELBORXE. 



probably some degrees of saltness prevailing within it, the rain 

 tears the slabs to pieces.* Though this stone is too hard to 

 be acted on by vinegar, yet both the white part, and even the 

 blue rag, ferments strongly in mineral acids. Though the white 

 stone will not bear wet, yet in every quarry at intervals there are 

 thin strata of blue rag, which resist rain and frost; ar.d are 

 excellent for pitching of stables, paths, and courts, and for building 

 of dry walls against banks, a valuable species of fencing much in 

 use in this village, and for mending of roads. This rag is rugged 

 and stubborn, and will not hew to a smooth face, but is very 

 durable ; yet, as these strata are shallow and lie deep, large 

 quantities cannot be procured but at considerable expense. 

 Among the blue rags turn up some blocks tinged with a stain 

 of yellow or rust colour, which seem to be nearly as lasting as the 

 blue ; and every now and then balls of a friable substance, like 

 rust of iron, called rust balls. 



In Wolmer Forest I see but one sort of stone, called by the 

 workmen sand, or forest-stone. This is generally of the colour 

 of rusty iron, and might probably be worked as iron ore ; is very 

 hard and heavy, and of a firm, compact texture, and composed of 

 a small roundish crystalline grit, cemented together by a brown, 

 terrene, ferruginous matter; will not cut without difficulty, nor 

 easily strike fire with steel. Being often found in broad flat 

 pieces, it makes good pavement for paths about houses, never 

 becoming slippery in frost or rain; is excellent for dry walls, 

 and is sometimes used in buildings. In many parts of that waste 

 it lies scattered on the surface of the ground; but is dug on 

 Weaver's Down, a vast hill on the eastern verge of that forest, 

 where the pits are shallow and the stratum thin. This stone is 

 imperishable. 



From a notion of rendering their work the more elegant, and 

 giving it a finish, masons chip this stone into small fragments 

 about the size of the head of a large nail, and then stick the, 

 pieces into the wet mortar along the joints of their freestone 



* "Firestone is full of salts, and has no sulphur : must be close-grained, and 

 have no interstices. Nothing supports fire like salts; saltstone perishes 

 exposed to wet and frost." PLOT'S Sta/., p. 152. 



