OF CORNWALL. 133 
remaining, thofe are eafily wafhed off, and the tin-ore remains 
behind in fuch purity, that the melters will give twelve parts of 
white melted tin for twenty parts of fuch tin-ore, and this is as 
good a price as the generality of tin-ore brings. 
Our waters are infe&ed by mundic more or lefs, according to SECT x 
the quantity which they pafs through, and the difpofition of the its ™ 
mundic either to retain or communicate the noxious principles of ni |J i °" s ter 
which it confifts. Arfenick, fulphur, vitriol, and mercury are the earth, and 
conftituents of mundic, yet thefe feemingly fo pernicious ingredients md&S. the 
are fo bridled and detained by their mutual a£tion and reaction, and 
by mixing with other minerals, that the water is not poifonous 
(generally fpeaking) even in the mine where it proceeds directly 
from the body of the mundic lode ; nay, in the mine, as I am well 
affured, this water will fometimes cure wounds, bruifes, and fores, 
if the habit of the body be not very corrupt. However, though the 
mundic in general is fo retentive of its arfenick that it will not yield it 
to water, and that nothing but fire can certainly feparate it, yet it 
is not always fo innocent ; for at times it yields that or fome other 
poifon fo copioufly, that I have known a tinner of the parifti of 
Ludgvan ', who, by walking his wounded leg in a very ftrong mun- 
dic-water in Ludgvan-lez mine, brought on fuch a gangrene that 
it foon killed him. In the fame work it was remarked, that the 
fmell of the mundic was about that time fo ftrong, that it altered 
the moft fanguine complexion of the labourers into pale and languid, 
and the effluvia of their cloaths were quite loathfome ; but in fome 
parts of this mine the water was more tainted than it was in others, 
and the damps and fleams much more offenfive. At Crowlifs, a 
village of Ludgvan, in the year 1739, a flock of geefe belonging 
to James George, taylor, went into the river as ufual, and, drink- 
ing heartily of the water, upon their return to the bank nine of 
them lay down immediately, and died ; but commonly this brook, 
though of a red turbid colour, by realbn of the mines and ftamping- 
mills through which it makes its way, is not poifonous, for many horfes, 
as they pafs daily, drink of it, and receive no harm. This mundic- 
tvater however is a great enemy to the finny breed, being either poilon- 
°us at times, or fo loaded with the dirty pabula of metals, that the 
young fpawn of filh cannot live in it ; for it is obfervable, that in 
fome brooks, where, about fifty years fince, there was plenty of 
fine trout (particularly the river Conar in Gwythien) fince the 
copper-mines have thrown into our ftreams this mundic-water, there 
is not a fifh to be feen. This mundic-water corrodes iron, by reafon 
Edmund Thomas. 
M m 
of 
