OBSERVATIONS. . 69 
pieces, dug formerly at Schlackenwalde 
and Schoenfeld, I found as 6015 :1000. 
Upon examination, the mineral lent 
from Cornwall for tungllen proved not 
to be it. The following experiments 
will Ihew of what it coniifts. 
§ 2. 
A part of this mineral, feparated from 
the adherent ochraceous iron ore, was 
mixed with an equal weight of fixed 
vegetable alkali, and expofed in a cru¬ 
cible to a ftrong heat. It did not melt, 
but was reduced to a powder, which 
while red hot, was poured out of the 
crucible, and obtained when it became 
cold, a dirty dark green colour, like 
the chamaeleon minerale. By pouring 
water upon it, it Ihewed the fame va¬ 
riety of colours as the alkalized manga- 
nefe: the colour of the lolution was at 
firft grafs-green, but foon after violet 
F 3 in 
