I2 8 n a t u r a l h i s t o r y
lapidific matter (when drained ofT^perluous moifture3 qnd difpofed
to fhoot) happens to. ijfe^fo'wilLthe: tendency of the fhoo'ts,! ».both
column and. point, b e : in ajlconcave beds, for inftanee, the points
will converges -in all convex ones’,,, they will .‘turn the contrary- way:
if the concave part, for example, ofi.the ammonites, Figs xaexii5-
ibe-fet with cryftals, -their points will tend inwards towards the-cen-
ctre, being thereto compelled by the ^gularncq^tbur, of
ammonis; but if the cryftal rifes -from a convex! bed, oE-iGtebienlar
lump then will the columns fpring as from onCiaommon cfcntre, and
point forth their radii, as in iRig^xkx ill. Pi- XIII. p. £$$£ iTthere
be a.thin plate of cryftal, equally e^pofed to>tke influence-of heat
or cold on each.fide, » with equal r.|om and/fqrce. to {hoot, slit; WiU
throw fortbits pomts .on cach furface, . a n d - t h f t ^ y ^ . ^ ^
the fibres began to ipfing, lhall,.he.rexa<% in the middle o f duch
plate of ciyftal, Eigc<vi,. ib,is alfo*rfy»tb be ^counted
ifor on the feme principles:, it ;is.the fection,;$%n'ovaL;lumprot
cryftal,. equally impregnated with
Horn 'a .line or. commiffure in^thei'-middle
lumns, being protrudcdmn every, fide with equal>fo|^, snauft. be,-.of
equal lengtbji if the lump had
would have: Ihot as from k center,, ,as in Fig:. xxSM-jap^Xsxy. ib.
the fib®» do. Hence I conclude, t h a t '^ Se ction
cryftals is nearly rectangular» to the plane of .the. bed from^hich
they iffue, and that
thefe bodies in the mmC abovermeritibned was lowing .ito^tfie Jgteat
variety of furfaces and; angles bto»,wbch diat.large b^Q fe ;e iy iM
was hardening when thefe-hexagonal .oyftals.'lhot from itsje^ettntjes.
, C H A P. x n . :
‘O f 'Sérnmetaif^'ffond'.
FR O M ftones of ornament,and curiofity.come we.next,to the
products of the mines, and,. Itones of profit, few countries,
according to the judgment of foreigners, exceeding .this county .in
the variety and plenty of minerals * but we have rather the pof-
feflion than thé enjoyment of tbs treafure Y f?r though this multitude
and variety appears every where in thofe parts moft fubjecbto
mines (I mean from St. Auftel weftwards), yet few of our people
r From Mr. Allen’s quarries at Bath, none of alphabet! fui mineralis fe credere .nullum fcrramm
that fort being yet difcovered in Cornwall. locum repenn qut minerarupi roultitudme et vari-
* Beecherus tefert deCornubia in dedication« etate antecellat. / i re j
I0',l'"(èftgroil6a
O F C O R N W A L L .
(engroffed af* | they are by tin and copper ) are either delighted with
or .even fenfibleiöf thè one, o#? at all the richer for the other.
Of bifrrmth, jpdtre, zink, naptha, antimony, lapisealàminaris,
and molybdæna^JÏ nhavè received fpecimens from feveràl parts of
èornwàlfb they?a#e juft enougtotötiwhet the appetite of the curious,
but hitherto notibnôugh to awafeè&the’ induftry or-fix the attention
o f ’théi owdefesl»
feveràl times, pure bu™*.
saflif in- a metallic» ftat^ I haveipsfeeived from the parilh óf St. Juft,
but, put all together, >they wiUdèkrGe màke a pound weight : it »is
-more pfaty^^mbn^wmoreiidilj^fed^ in Mr. Beauchamp’s cobalt
mine, in llhfeip^tilkof Gv^eüajf/léc
-rvSpeltre ore-I' have» had Tromira-rmine near St: Columb, and Dr-Spete
eWöbdwafd, Cat. vol. II:>ipageu8<3^ mentions' fome from St. Merwin
near Padftow. One femimetallic fpecimen, which I have from
.Camborn, óf a brow'n, cinereous? colour,! ’ very clofe-grained, pon-
iderous, andmf v uniform Ihudrore, has » been taken for stink \
Vj } O f Naptha ! I have »leen but one lpecimen, which Came from Naptha.
-Tolgarie work, in the parilh of Camborn. |
In the parilh o f Endelian there are lèverai veins o f antimony s b c t . il
.mixed. With'fmallrfpots of copper and fome lead, there called R of -Antim0ny-
tèarrockfs *li(as Grew;-fays, Mufaeum R;?S.i?pa||b 334) : thefe veins
»r.un .femctimes north and fofith, but Oftener eaft' and weft : the
toodbh and;fouth veins Site the biggelt j and when the eaft and weft
»Veins rjoihji of crofs .the former, .-they commonly make a bunch of
:ôre from>:one footrto two fectrwide, all of folid antimony. Some
àïitimony- is ' now raifed in the lands o£ the Reverend Mr. Hearle, in
St. Minver, a parilh adjoining to the former. Antimony has allb
been found? in St. Auftel parilh, » in St. Stephen’s at Howton, and in
BÉ place called by Dr. Woodward?(»Cat. vol. I. page 184) Barbaiy-
AVork |f!iteSt. Kew panlh allb, as the feme author (Cat. vol. II. p. 20)
^nfórms us, and, I doubt noty; isf&rown away às'ulèlels in a greater
number of places ;;büt there'?arff’fio workings on this mineral in the
•county at prefent, confiderable 'enough to be more particularly mentioned.
It need only be oblèrved, î that antimony is reckoned to be
»of an intermediate nature betwixt gold and filver, and by the texture,
and weight of its ore, > lb likely to contain metal, that the
late famous Dr. Boerhave tried for a whole year to extrait from it a
real metal, »but without luccelsc. -j
• n By Mr. Ornfkold, 9 learned Swede. of that neighbourhood. See the Map annexed.
: ,b From a Manor of anejent note there, ..I c Theor. Chem. page 13»
fuppofe, more ahbiinding iii antimony than the reft
L l Manganefe,