lead 
212 NATURAL HISTORY 
sect. v. Our lead-veins in Cornwall generally run eaft and weft, but are 
Lodes of not large in dimenftons, nor fo lafting as the veins of this metal 
in fome parts of Wales, in Derby fhire, and other parts of England, 
and feldom or never yield much lead, excepting when they are 
crofted by other lodes, and then they make what the miners call a 
Bunch, or bank of ore, juft in the place where the fiflures interfed:. 
Tho’ this be the general courfe of lead-veins with us, yet the wideft 
and richeft lodes of this metal which we have in Cornwall, are obferved, 
as I have been informed, to run north and fouth. Lodes ol lead in 
Britain, fays Pliny p , when exhaufted, after refting awhile, are re- 
plenifhed with the fame ore. The matter of fad is much to be 
queftioned ; yet if there be fuch fucceftive renovations, it cannot 
be from the air, as he imagines, but from the water, which circu- 
lates the contents of the adjacent Jlrata , and depofttes them in the 
retentive hollows and fiflures of the mine. Lead does not throw 
itfelf into fuch a variety of figures as tin ; the only regular ftiape 
in which I have yet feen lead-ore in Cornwall, is that or the paral- 
lelopiped kind, called the Dice, or teflellated ore : three of thefe 
in their natural fize, are inferted Plate xx. Fig 5 , xxxm, xxxiv, and 
xxxv ii. (the largeft grain of lead I have feen) ; and, lor the fatif- 
facfion of the curious, two fpecimens of the Tipperary lead are ad- 
ded, Fig 3 , xxxv and xxxvi, ibid. 
sect. vi. 
Little 
wrought in 
Cornwall. 
Though lead has been difcovered in fo many parts of this county, 
we have not any one mine of note, excepting only in St. Iffy near 
Padftow, in prefent working, upon account only of the lead ; but 
as our grounds are fo fubjed: to this metal, and in fome places the 
ore is fo rich in filver *, and yet fo latent, difguifed, and, as appears 
from what has been faid before, of fuch various affociations, that 
no two Mils can be more unlike than fome forts of lead ore ; and 
as new difguifes, not here particularized, may occur to the curious, 
and particularly as the ore richeft in filver has no more than the 
appearance of fpar, and fometimes common clay, the gentlemen of 
Cornwall have reafon to be cautious that a great deal of this preci- 
ous metal be not thrown away, as good for nothing, by the unlkil- 
ful miner, and that the feveral forts of lead-ore, as they are raifed, 
be carefully examined, and feparately tried ; and becaufe few miners 
know or can diftinguifti lead, or will be at the pains of procuring 
proper information for their mafters, when they meet with any 
thing new, it is much to be wifhed that gentlemen, who have pro- 
perty and leifure, would acquaint themleives with the eafy procels 
of allaying metals, or would fubfcribe towards the maintaining a 
p Lib. xxxiv, chap. xvii. 
i See above of Guarnek. 
general 
