m- M J: 
very well for the working. Some of the great mines, 
however, have very large veins, with a number of other 
Jmall ones very near each other. There are alio veins 
crofling one another fometimes met with, which are called 
contras, vulgarly counters. 
Sometimes two veins rundown into the ground in fuch 
a manner that they meet in the direction of their depth ; 
in which cafe, the fame oblervations apply to them which 
are applicable to thofe that meet in a horizontal direc¬ 
tion. Sometimes a,vein will fuddenly dilappear without 
giving any warning, by becoming narrower, or of worfe 
quality; which by the miners is called a J'tart, or leap, and 
is very common in the mines of Cornwall. In one day’s 
time they may thus be difappointed in the working of a 
rich vein of tin, and have no further lign of any thing to 
work upon. At the fraCtured extremity of their vein 
they perceive a body of clay or other matter; and the me¬ 
thod of recovering their vein is to drive on the work in 
the direction of the former part, lb that their new work 
lhall make the fame angle with the clay that the other part 
of the vein does. Sometimes they fink a fhaft down from 
the 1'urface ; but it is generally a matter of difficulty to 
recover a vein when thus loll. 
The method of difeovering mines is a matter of fo much 
difficulty, that it l’eems furprifing how thofe who were to¬ 
tally unacquainted with the nature of metals firfl came 
to think of digging them out of the earth. According 
to Lucretius, the dilcovery was made by the conflagra¬ 
tion of certain woods, which melted the veins of metal 
in the earth beneath them; but this feems rather to be 
improbable. Ariftotle, however, is of the fame opinion 
with Lucretius; and tells us, that, fome fliepherds of 
Spain having fet fire to the woods, the earth was thus 
heated to fuch a degree, that the filver near the 1'urface 
of it melted and flowed into a mafs ; and that in a fliort 
time the metallic mafs was difeovered by the rending of 
the earth in the time of an earthquake. The fame ftory 
is told by Strabo, who aferibes the dilcovery of the mines 
of Andalufia to this accident. Cadmus is laid by fome 
to have been,the firll who difeovered gold ; while others 
aferibe this to Thoas the Thracian, to Mercury the l'on . 
of Jupiter, or to Pifus king of Italy ; who, having left his 
own country, went into Egypt, where he was eleCted 
king after the death of Mizraim the fon of Ham ; and, on 
account of his dilcovery, was called the Golden God. 
Others fay, that Eaclis, or Casacus, the fon of Jupiter, or 
Sol the fon of Oceanus, was the firll difeoverer; but JEC- 
chylus attributes the difeovery not only of gold, but of 
all other metals, to Prometheus. The bral's and copper 
mines in Cyprus were firll difeovered by Cinyra the fon of 
Agryopa ; and Hefiod aferibes the difeovery of the iron- 
mines of Crete to the Cretan DaCtyli Idaei. The extrac¬ 
tion of lead or tin from its ore in the ifland of Caffiteris, 
according to feveral ancient authors, was difeovered by 
Midacritus. The Scripture, however, aferibes the inven¬ 
tion of brafs and iron, or at leall of # the methods of work¬ 
ing them, to Tubal Cain before the flood. 
In more modern times, we know that mines have been 
frequently difeovered by accident; as in fea-cliffs, among 
broken craggy rocks, by the walking of the tide or floods, 
alfo by irruptions and torrents of water iffuing out of 
hills and mountains, and fometimes by the wearing of 
high roads. Mr. Pryce mentions another way by which 
mines have been difeovered, viz. by fiery corulcations; 
which, he fays, he has heard from perfons whole veracity 
he is unwilling to queltion. “The tinners (fays he) ge¬ 
nerally compare thefe effluvia to blazing liars or other 
whimlical likeneffes, as their fears or hopes fuggell; and 
fearch with uncommon eagernefs the ground over which 
thefe jack-a-lanterns have appeared and pointed out. We 
have heard but little of thefe phenomena for many years 5 
whether it be that the prefent age is lefs credulous than the 
foregoing, or that the ground, being more perforated by 
innumerable new pits lunk every year, fome of which, by 
the Itannary-laws, are prevented from being filled up, has 
N E. 
given thefe vapours a more gradual'vent, it is not necef- 
lary to inquire, as the fact itlelf is not generally believed." 
Mines, however, are now 1 molt commonly difeovered, 
by invelligating the nature of fuch veins, ores, and Hones, 
as may leem molt likely to turn to account; but there is- 
a particular lagacity, or habit of judging from particular 
figns, which can be acquired only by long practice. 
Mines, efpecially thofe of copper, may alfo be difeovered 
by the harlh and dilkgreeable talle of the waters which 
iffue from them ; though it is probable that this only hap¬ 
pens when the ore lies above the level of the water which 
breaks out; for it does not feem likely that the tujie of; 
the ore could ajcctid, unlefs we were to fuppofe a pond or 
lake of water Handing above it. The prefence of copper ; 
in. any water is eafily difeovered by immerging in it a bit 
of polilhed iron, which will thus infiantly be turned of a 
copper colour, by realon of the precipitation of the me¬ 
tal upon it. A candle, or piece of tallow, put into wa¬ 
ter of this kind, will in a fliort time be tinged of a green 
colour. 
Another and Hill more remarkable method of difeover¬ 
ing mines is faid to be by the virgula divinitoria, or divin¬ 
ing rod, which, however incredible the flories related con¬ 
cerning it may be, is Hill relied on by fome, and among 
others by Mr. Pryce. It is not known who was the in¬ 
ventor of this method ; but Agricola fuppoles that it 
took its rife from the magicians, who pretended to dilco- 
ver mines by enchantment. No mention is made of it, 
however, before the nth century, fince which time it hast 
been in frequent ufe } and the corpulcular philofophy has 
even been called in to account for it. But, before we 
pretend to account for phenomena fo very extraordinary 
as thofe reported of the virgula divinatoria, it is neceffary, 
in the firfl place, to determine whether or not they exiit. 
Mr. Pryce, as has been already hinted, believes in it, 
though he owns that, by realon of his conllitution of mind 
and body, he is almofl incapable of co-operating with its 
influence. The following account, however, lie gives 
from Mr. William Cook worthy of Plymouth, a gentle¬ 
man of known veracity and great chemical abilities. He 
had the firfl information concerning this rod from one 
captain Ribeira, w-ho deferted from the Spaniffi fervice in 
queen Anne’s reign, and became captain-commandant 
in the garrifon of Plymouth ; in which town he latisiied 
feveral intelligent perfons of the virtues of the rod, by 
many experiments on pieces of metal hid in the earth, and 
by an aCtual dilcovery of a copper mine near Oakhamp-’ 
ton, which was wrought for fome years. This captain 
very readily Ihowed the method of uling the rod in gene¬ 
ral, but would not by any means difeover the fecret of 
dillinguifliing the different metals by it; though, by a 
conflant attention to his praCtice, Mr. Cookworthy dif¬ 
eovered it. Captain Ribeira was of opinion, that the only 
proper rods for this purpofe were thofe cut from the nut 
or fruit trees ; and that the virtue w'as confined to cer¬ 
tain perfons, and thofe, comparatively fpeaking, but few; 
but Mr. Pryce fays, that the virtue refides in all perfons 
and in all rods under certain circumfiances. “The rod 
(fays he) is attracted by all the metals, by coals, lime- 
ltone, and fprings of water, in the following order: 1 
Gold; a. Copper; 3. Iron; 4. Silver; 5. Tin; 6. Lead; 
7. Coal ; 8. Limeflone and fprings of water. One me¬ 
thod of determining the different attraClions of the rod 
is this: Stand, holding the rod with one foot advanced ; 
put a guinea under that foot, and a halfpenny under the 
other, and the rod will be drawn down ; fliift the pieces 
of money, and the rod will be drawn towards the face, or 
backwards to the gold, which proves the gold to have the 
ffronger attraction. The rods formerly ul’ed were fhoots 
of one year’s growth that grew forked ; but it is found, 
that two feparate Ihoots tied together with packthread or 
other vegetable fubffance anfwer rather better than fuch 
as are naturally forked, as the lhoots of the latter are fel- 
dom of an equal fize. They are to be tied together by 
the greater ends, the fmall ones being held in the hands. 
> • Hazel- 
