[ 49 1 ] 
may alfo contain fome fmail minture of ochery- 
earth, which may give it its yellow caft. 
N° 20*' A fhining kind of ftony clay, called 
by the miners Jill , lying in large beds in coal 
grounds, it ftrongly refills the fire, and fome of it, 
by germination, yields alum. 
W. BROWNRIGa 
ERRATUM. 
