charafters, that diftmgtsifli one fort from another f 
^4. What proportion of metal it aiFords ? ( As in our Iron- 
Mines\\% obfervedj that about three Tuns of Iron-fione will af- 
ford one Tun of metal ; And I have had Lead-ore^ which an 
Ingenious man, to whom I recommended fuch Try als, affirm- 
ed to me to afford three parts in four of good Lead. ) 
6 5. Whether the Ore be pure in its kind from other metals, 
and, if not, of what metals it participates y and in what propor- 
tion ? Which is eipecially to be enquired into, in cafe the Mine 
be of a ^'^/^ metal, that holds a noble mttz\i{ As I have known 
it obferv'dj thatLeadcOre, that is poor in its own metaljafFords 
more Silver, than other ; and I remember, that the Ore lately 
mention'd , being rich in Lead, fcarce afforded us upon the 
Cuppel^ an atome of Silver, And Matthejius informs us, that a 
little Gold is not unfrequently found in Iron-ore. And I have 
by mefome Gold that never endured the Fire^ taken out of a 
Lump of Tin^Ore.) 
Ahut th fixth Title. 
66. Whatare the Mechanick and prsevious Operations 3 ai 
Beating, Grinding, Walhing, ^c. th^t are ufed to feparate 
the Ore from the Heterogeneous Bodies 3 and prepare it for the 
Fire f Or whether the Ore requires no fuch preparation f (as 
it often happens in Lead, and fometimes in Iron, a? 
67. Whether Mertury bemadeufe of, to exrraS: the nobler 
from the bafer metals f ( as is their pradiife in Feru^ andiothet 
parts of the ^F'/?/?-/;?^^^.) 
68. Whether the leaving the Oreexpos*dto the open Air 
and Rain for a good while^be ufed as a Pra^parativef (as I have 
feen done in Iron-flone.J 
d^, Whether the Burning and Beating of the Ore be ufed to 
prepare it for the Furnace ? ( as is pradtifcd in Irouy and almofl 
alwayes in Copper :) And ^ in cafe they ufe more than once, 
how often they do it; (for Copper-ore is in fome places waflied 
S. or 10. times, and in others, 12, or 14. ) and with what cir- 
cumflances ; as, how long the Ignition lafts at a time, whether 
the Ore be fuffer'd to cool of it felf, or be quench'd > whether 
it be wafhed betwixt each Ignition 
70, What Flux-powderSj and other wayes they have to try 
Z z 2 and 
