NATURAL HISTORY OF SELBORNE. 9 



firestone will not succeed for pavements, because, probably some degree 

 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 ; 

 and 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 walls ; this embellishment 

 carries an odd appearance, and has occasioned strangers sometimes to 

 ask us pleasantly, " whether we fastened our walls together with ten- 

 penny nails." 



* " 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 Staff, p. 152. 



