§2 
The fpecimens moft intereftinz to the 
mineralogift are : 
ift. Glafs changed into Porcelain of 
Reaumur, both radiated, and containing 
in its crevices. filiceous cry ftals. 
2d. Malleable iron, which had formed 
the bars and cafements of windows, &c. in- 
creafed to twice or thrice its original bulk, 
and rendered brittle; its internal ‘part 
either cry ftalized in o€tacdral prifms, at- 
tractable by the magnet ; or changed, as 
it thould feem, in its whole fubftance, the 
external part being brittle and laminated 
in its ftruéture like many of the ores of 
iron, while the central part appears to be 
pure iron cryftallized in grains or plates, 
fometimes of three lines acrots, of a bril- 
liant filver colour, without any traces of 
that azure appearance which is defcribed 
in the native iron of the famous Siberian 
mafs, and, in a fpecimen in. my pof- 
feffion, from the province of Quito, in 
South America; however this iron, fo 
beautiful, is alfo brittle, on account of its 
granulated and laminated texture. 
3d. The fteel of the lock of @ mufket 
is {wollen and reduced to grains of a 
rather large fize. 
ath. The bells of fome churches, fur- 
rounded by the lava, have become foft and 
bent, andare covered over, throughout the 
whole of their furface, both within and 
without, with a laminated metailic cruft of 
from two to three lines thick, and th's 
cruft difcovers throughout an evident 
cryftallization; fome of the cryftals even 
fhoot from the cruft to the length of fix 
lines, being pyramidal, with four rhom- 
boidal faces. Upon the internal fuper- 
ficies of the cruit, which was in contact 
with the bell, certain little cry{tals were 
obferved with the lens, which have every 
appearance of blend, and it appears pro- 
‘bable they may be fuch. 
sth. The common copper coin, as like- 
wife certain brafs crucifixes, difcover 
cryftals on their furface, and are become 
brittle. 
6th. The gold coin is found covered 
over with a fubtle blackifh crufft, but 
which it readily lofes on rubbing with 
the fingers ; this cruft it probably derives 
from contaét with copper. 
“th. Some filver coin ‘is fufed; 
althongh other copper monies have re- 
filted this degree of heat, they have been 
fometimes found attached, by means of 
the filver coin, which had melted. 
8th. Lead, fufed and running, has be- 
come hard; fometimes like litharge, at 
others like minium, folid, compact, and 
of the brighteft colour. -  . 
: 5 
Catalogue of Volcanic Transformatians, by Dr. Thompfon. [ Aug: 
gth. A candleftick, formerly of brafs, 
» has been cifcovered, totally changed, as 
well in external appearance as in internal 
ftructure ; without, it exhivits a moft 
brilliant crvftallized furface, and within, 
a furprifing luftre, efpecially in its cavi- 
ties, which confiderably refembles. a 
groupe of numerous cryftals,of tranfpa- 
rent blend, of a‘coffee colour; and mixed 
with many o¢taedrons of both a bright 
and a dirty red copper, which might 
lead one to fufpeét that the bright red of 
certain copper ores is not effential to 
the copper itfelf, but, perhaps, arifes 
from a mixture of iron. The internal 
fuperticies of the cavities of this candle- 
{tick appear-cryftallized, like that with- 
out, equally brilliant, and fomewmes 
radiated: although the cryftals of red 
copper {cattered withoutiide are entirely 
oétacotals, on breaking a thick place, or 
knob, of the candleftick, there are found 
in the central part, which refembles iron 
flag, meft beautiful cubes of red coppers 
as brightas the fineft Siberian {pecimens. 

To the Editor of the Monthly Magazine. 
SIR, 
I DO not mean to deny that my habits 
are unfcientific, when I requeft that 
your fheets may be the medium of an 
attempt to prove that Mr. TayLor has 
not fixed the charge upon me. In his 
animadverfion upon my defence of the 
happinefs of youth, he has confined him- 
felf to the fubjeét of happinefs in general, 
in which I will follow him ; only obferv= 
ing, that he takes for granted, what was 
denied, that the youth has no pleafures 
but thofe of fenfe: that I deemed the — 
frolics of the calf enviable, only when 
compared with the energetic conflicts 
of the bull at the ftake : and shat, allow- 
ing Mr. T. all he contends for, he has 
not, in any degree, affected my argu- 
ment, fince he has taken a view merely 
of the poffdihties of happinefs arifing 
from the nature of the youth and man, 
without, in the leaft, confidering the im- 
pediments which arife againft that hap- 
pinefs, from the exifting evils of fociety 5 
evus which render man more unhappy 
than the child, precifely in that degree 
in which he has greater capacities of en- 
joyment. 
I did not define the term happinefs, 
for T remembered the poet’s diftich : 
Who thus define it, fay they more or lefs 
Than this—that happinefs is happinefs ? 
Happinefs, as well as pleafure, being a 
general term, is expreflive of no idea, 
but is indiferiminately applied to the in- 
finite 
