264 VII. EARTHS AND ALKALIES.— 



Roman ochre. Hard, heavy, very deep or brown yellow ; 

 firm, regular, harsh, dusty, colouring very much ; burns rather 

 hard, and to a fine purplish red : Somersetshire, also near Rome ; 

 all used as paints. 



Founders'* loam. Deep yellow, fine, soft, with spangles of 

 mica, slightly colouring : burns to a pale red, but not harder ; 

 Thrup, in Northamptonshire, also near Highgate Archway : used 

 by founders for moulding. 



Red Armenian bole, Bolus Armena rubra* Deep red, hard, 

 heavy, close, rough, colouring the hands ; burns rather harder, 

 and to a brighter red ; astringent and alexiterial. 



Common Lemnian earth. Terra Turcica. Pale flesh red, 

 not very close, heavy, slightly unctuous ; burns very hard, and 

 to a dusky yellow. 



German bole. Bolus Bohemica rubra. Pale yellowish red, 

 compact, but unequal, heavy, smooth ; burns rather harder, with- 

 out changing colour ; astringent. 



Terra Lemnia rubra. Pale red, variegated with yellow, 

 close, very heavy, rough, but scrapes smooth, not colouring ; 

 burns very hard, and to a fine deep red : Lemnos ; astringent, 

 sudorific. 



Bole of Blois, Bolus Blesensis, Bolus Armena lutea. Pale 

 red with an orange cast, close, hard, heavy, not colouring, effer- 

 vescing violently with acids, very astringent taste, burns to a stony 

 hardness and a dark red ; astringent, sudorific ; highly commended 

 in the plague. 



French bole. Bolus rubra Gallica, Pale red, with white 

 and yellow veins, heavy, close, slightly unctuous, not colouring, 

 slightly astringent ; burns very hard, but of the same colour ; 

 astringent in powder. 



Barros, Bucaros, Terra Portugallica, Fine florid red, heavy, 

 harsh, colouring, strongly astringent, burns brighter but not 

 harder ; used in dysentery and in dentifrices. 



Bradwall-hall clay. Brick-red. — Halljield colliery, clay, 

 A marie, burning to a light red of four different shades : both are 

 used in making Staffordshire pottery. 



Mahogany earth. Pale red, sometimes darker, compact, 

 heavy, smooth, but neither glossy nor unctuous, not colouring, 

 burns very hard without change of colour ; Isle of Wight : used 

 in painting, and to stain wood of a mahogany colour. 



Soft ruddle. Clay iron-ore^ Ruhrica fabrilis mollis. Dusky 

 red, loose, very heavy, extremely unctuous, with an oily gloss, 

 colouring very much ; burns very hard, externally little altered, 



