e 
OBSERVATIONS. 53 
were made in the manner mentioned in 
§ 2. The firft of a white colour, con¬ 
fiding of tin, was ftrongly heated in an 
earthen veflel, by which a fmell of arfe- 
nic was perceived. The whitilh colour 
of calx of tin was changed into a flelh 
colour, which it generally acquires by 
being long heated. After fame wax was 
deflagrated with it, it weighed 61 grains, 
and fcarcely one grain was attracted by 
the magnet. The fecond precipitate of 
a greenifh colour was likewife ftrongly 
heated, and became by this means a black 
heavy powder. Digefted with nitrous 
acid in a boiling heat the folution became 
blue. A light brown calx of iron re¬ 
mained, which dried and heated with 
wax weighed 18 grains, totally attract¬ 
able by the magnet. 
The quantity of iron contained in half 
an ounce of this ore was 19 grains in a 
date of phlogifticated calx ; fo that in 
the former fpecies there was found a 
much lefs portion of iron. 
E 3 I 6. 
r 
