2 3 
OBSERVATIONS, 
iplendor alternates in fome fpecimens with 
dull grey and blackiih fpots. It is not 
confiderably hard, but very brittle. The 
fpecific gravity varies according to the 
quantity of metal it contains: thofe pieces 
which are more pure and white, and 
which are the richeft of tin, are as 
435 : I0 °* Excepting copper-pyrites, 
which is interfperfed in fmall particles 
through it, no foreign body is mixed. 
As I am not acquainted with the 
experiments of Mr. Raipe, by which he 
thought himfelf intitled to declare it ful- 
phurated tin-ore, I will communicate in 
the following pages the analyhs I have 
made, which fhew it to confift of ful- 
phur, tin, copper, and fome iron. The 
mixture is fo exadt and intimate, that the 
way of powdering and waftiing, which 
otherwife is very proper in tin-ores, is of 
no ufe. Mr. Rafpe propofes to name this 
ore bett~metal ore; which denomination 
would be more juft if there were a larger 
proportion of copper to the tin. 
: C 4 
COPPER 
