C 737 ) 
II. Two Letters concerning fever al Copper Mines 9 
in anfwer to feme Queries propofed by Dr. Li- 
fter, 5*. R S. who communicated them to the 
Publifher. 
LETTER I. 
S I R, ; 
a Ccording to your defire I have given you an An* 
l\ fwer to the Queftions about the Copper Mines to 
the beft of my knowledge, which are as followeth. 
The Firft Query is, What quantity of unwrought Copper 
Ore is left upon the place i and where it zs> and in whofe 
hands , and what is the reputed value of a Tun of un- 
wrought Copper Ore ? 
To which I anfwer, That there is a heap of Ore ly 
Darwent near Kefwick and I fuppofe no body lays 
Claim to it, but it is not worth any thing ; for being 
there fo long, the Weather hath eaten out all the Copper 
that was in it. And for the value of a Tun of Copper 
Ore unwrought, I know not what it is worth, neither 
is there any in this Country that can tell ; neither can 
any Man know, except there were Ore got, that the 
Goodnefs or Badnefe may be (een by the more or left 
mixture of Stone that is in it, or by other Symptoms of 
kindly Ore. 
The Second Query is, What ufe can he made of the 
Slaggs of Copper Ore ? and whether they can be wafked 
over again , as is praclifed in Lead" works ? 
The only Anfwer that I have to this Queftion is, That 
I do not know any thing of it, neither can it be known 
C c in 
