261 



VII. EARTHS AND ALKALIES. 



EARTHS AND CLAYS. 



Terra lemia alba. Dirty white, with a grey cast, very 

 heavy, rough, harsh, not colouring, burns very hard, outwardly 

 dark brown, inwardly brownish yellow ; used in dysenteries and 

 malignant fevers. 



Bolus Armena alba. Bright white, compact, very smooth 

 and soft, not colouring, burns very hard, and at last forms a 

 whitish grey glass ; sudorific. 



Bolus Candida, Axungia Iwub. Pearly white, light, smooth, 

 not unctuous nor colouring ; burns to a very pale whitish yellow ; 

 astringent, cordial. 



Tobacco-pipe clay, Argile d*Abondant, A. de Montereau, 

 Cimolia alba. AVhite, smooth, unctuous, slightly colouring, burns 

 rather hard, and very white : used to make tobacco-pipes and 

 white stone- ware. 



Waite lumber stone. Terra siaillata alba. Terra Samia 

 vulgaris. Tobacco-pipe clay, made into cakes with a stamp; 

 used as an astringent, and to take grease out of woollen cloth. 



SoAP-ROCK, Spanish chalky Parcetonium, Creta Hispanica, C, 

 sartoria. White, firm, compact, weighty, hard, smooth, unctuous, 

 not colouring, burns to a stone ; writes upon glass, and if rubbed 

 off, the marks become again visible by breathing upon the place : 

 used by tailors to draw their patterns, to take out grease spots, 

 and to engrave upon, the engraving being afterwards hardened 

 by fire. 



Kaolin, Porcelain clay. Dry, friable, infusible. That of 

 Cornwall used to make English china and fine pottery ; that of 

 Limoges to make Sevres china, and exported to Copenhagen for 

 the same purpose ; that of Passau, to make Vienna china. 



Terra Cimolia. White, compact, smooth, colouring, burn- 

 ing rather harder ; found in the island Argentiere : used to wash 

 clothes. 



Chalk, Creta, C. argentaria. White, soft, marking lines; 

 when newly burned, it grows hot with water, and falls into 

 powder; antacid: used in heartburn, gr. x — 3ij ; externally ab- 

 sorbent, and as a crayon. — Hard chalA. Coars*.\ 



Whiting, Spanish white, Blanc d' Espar/ne, Blanc de Troyes^ 

 Calcis carbonas prceparata, Creta prceparata. From soft chalk. 



