^ N A T U R A L H I S T O R Y
of the vitriol with which it is impregnated, very foon; fo that, ih
our hydraulic «nines', the piftons bf the pumps in hbpper-ffttries
myft bfe made of brafs, or they are eaten away arid becotne ufclefi
j in 'a little* time. *
s e c t . xx. ; Mundic mixed with tiarth will d|$Tby all ^vigetation, ifo^fts
with ear*, being too acrimonious and fiery to enter thy finerireffels of jfomtS
without rending and utterly {polling them 5 for Which reafori the
ninndic, pulverized the fbpapin^^mll) ’isVairied off to mix with
the fpa-gravel and day, and effedually prevents all grafs and weed,
from growing in grav^b-Walks.
sect. xii. Fire has a much worfe effed upon mundic than the other efe-
wth fire, ments, and throws it into its mo& fatal ftate; for when it has been
fomewhat burnt, and the folphur which fheathed the pcdfonoWs
fpicula o f arfenick is difperfed, the arfenick &iSs ^ithont rdffraihti
In the management o f the furnace, called the Bumfog-hoOfe-, great
caution muff he ufed: the arfenick, which flies off from the Ore,
1ms feveral refts and paufcs; it fixes upon the ftem and head of the
iron rake which ftirs the tin, in bundles of white-yjelfow duff ;
and here it is reckoned moft poifonous, as being leaft mixed j but
it is alfo ftrongly poifonous from the bottom, of -the flue ofr the
chimney upwards,- where, although it is a mixture o f ^KihaiCj frit:
phur, and foot of pit-coal as well as arfenick, it is yet' fo fetal, that
a perfbn of an adjoining parjfh to Ludgvan, rafMy looking deWh;
and prying into the chimney of one of thefe Burmng^houfe, was
feized inftandy in fo violent a manner, that, nOtWkhftaudmg alii
proper affiffance, he foon died* The workmen ate oftentimes
obliged to fweep but thefe furnaces and clearilhe chimney, a feerice
o f no little danger; it is ufoal therefore 'to put a cloth' before their
mouth and nofe when they are upon this duty; but Elijah Bond,
a youth of the parifh of Ludgvan, fweeping out what they call1 the
oven, (the place where the tin-ore lies roaftingj at Rofangtows
Buming-houfe, January 25, 1750, without the neceflary precautions,
was taken ill immediately, and, though he, had the ufual
remedy of Oil given him, he died that evening,
sect . x iu. The frnoke of burnt-mundic when i t leaves the chimney being
with fmpke. more difperfed, is not foon, but as forely fatal -to all tender herbs
and plants, and bees of the adjacent neighbourhood* as it lights
upon them; and the fire-men* who attend' this proeefs, greatly
impair their conftitutions, if they make it their foie and eonftant
employment.
The
O O R N ’ W 'A L, L. 135
The thtfefc fores of mundic abtfve-frientibnbd, "Sedioft vii, differ sect,xw.
not oply in Colour, but in the moife flecinye aftd-'lefs^ variable, pro- Weight of
■ ■ ■ ■ ■ ■ ■ ■ i l l j I H Hfl S lS f I I ■ a -' mundic. petty, weight.
fPlate-mundie ftriated weighed to Water '(Au-y ^ „ 1
] guft 19 as - -• - - -J g p o 10
Cflate-mundic' granulated :t/ik )
f BKifs-colowed cObical ifthridiC - - 1 ?
- - ’ ■* gasakfed ‘L & h ^ to **
f Brown-mundic . - - **,
; tSbcond fefople of 10°. *. - 4-7^1 ° **
The plate-mundie therefore is in weight to water neaMiS feveh fo
one ; the brafs-coloured is not Jb-heafry, b r i n g ' :■
and r%-:hBQW»<fe folllighter, being but-as 4^ -&»|<jfMei-^
^IrNotwithftaading that the fpecifical weight fof, mundic exceeds sect.xv.
rfovro f mftft foflils, and that it has, to all OUtWard appearance o fIts ppiu“ -';
«fJmir arid texmre,foch a near refemblance to brafs, it is'fo prdj|-
n^nt with folphur and arfenick, 'that, though a fierce fife will mbit
it, yet will it fly into powder under the hammer, and by no flux
hitherto dafeovered caft it be reduced into a Metal. Nbfrrithftand-
iag the failure of all former experiments, the appearance prohujelt
fo mutch, that the late learned Dr. Boerhavbfent to me by a friend
for all the forts o f it which. could be procured; in-ffrong confidence
that he fhould be able to find out a method o f making it turn to
account. Ail the forts were accordingly furthered to him; btft^lM
death o f that great chemift foon after, deprived tfs ©£ thdfe'affidu-
ous and fkilful experiments, which, under his Ojfey, might have been (
bleffed With difeoveries bf ^eat importance.
Mundie will yield in evaporation its quantity o f folphur and
' arfenick ; but thefe are fo much eafier, and afoa lefi^pehbe, tdbd
'procured other'waya* that it,is lift Wtoflh whfle> etafleSyduk'aRe^-
them by burning moniic. Mr; ftiyie ° ptetetired by dlftilfetionl|four
ourfoes of good brimffone froth three pokntls of fhefe^'ffohes; and
fays, that they contain particles o f
na^y be thence procured; and that a fldlfol per'fon may poflib^
make a proficable ufe of marcafrtes, either by fixing the volatffo
gold or filver contained thereM, or by graduating fil^brifoy theif
means ;, and Kentteannus obferttes, that fofne marbafites bbritafn
filver,L;otherS'* gofo;- and othert feth, ibid. 1 41hb whifo^br p%fe-’
mundic far exxteedfc the ©th®r forts ite weight; and, if I ‘am riot
I
...» Dr. J. Andrew ef ExistfeV AM* »iieyd»*' * Bodrh. 'Phwjr.,‘df^Svemiftry, Eng^fo- \
m i f -