8 THE NATURAL HISTORY OF SELBORNE. 
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 color, 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 color 
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; 1s 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 frag- 
ments 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 tenpenny nails.” — 
