MINERALOGY. 95 



SECT. LXXXVII. 



1. Indurated Bole, Bolus indurata. 



A. Of no vifible particles, Particulis ImpaU 

 pabilibus. 



This occurs very often in form of flate, 

 or layers in the earth, and then is made 

 ufe of as an iron ore. However, it has 

 ufually been confidered more in regard to 

 its texture, than to its conftituent parts, 

 and has been called flate, in common with 

 ieveral other earths, which are found to 

 have the fame texture. 



a. Reddifh brown, from England -f\ 



b. Grey, from Coalbrookdale, in Shrop- 

 fhire, and mod collieries of England." 



SECT, LXXXVIII. 



B. Of fcaly particles, Particulis fquamofis : 

 The hornblende of the Swedes. 



boles 19 Hill thought to comprehend fo many varieties. Thus 

 the Cologne clay (Seel. Ixxviii.) is by the druggifts ranked 

 among the white feaied earths, and is called a white bole: 

 and this lame clay is by the Svvedifh potters called Jingles k 

 jcrd, or Engl iib earth; and by the tobacco-pipe makers, 

 Pip-Ura. or pipe clay, &c. which (hews how great a ccnfulion 

 tftere muft enfue, if the knowledge of thefe bodies was not 

 founded upon a farer ground than the colour, figure, and 

 names invented by common mechanics. Sirce the molt part 

 of thefe terra figillata t or fealed earths, are found to contain 

 iron, I conclude, that the bole muft be a martial clay ; and, 

 as fuih, it feems to be more fit for medical ufes than other 

 clays, if any dead earth ir.ulr. be ufed internally, when there is 

 fuch an abundance of finer fubftances. 



f in molt collieries between the feams of coal, as at Han- 

 ram, in Kingfwood, near Briiloi, Bianavon, in Monznouth- 

 fhire^ &c t D. C. 



Is 



