SECT. VII. 
Of talc in 
Cornwall. 
JI2 NATURAL HISTORY 
of the brown foliaceous talc, a tin-work, in the parifh of St. 
Tuft ', affords a fair fpecimen ; the leaves thin and elaftic from the 
tourth of an inch downwards in diameter, of no determinate 
figure, nor inferred in any order. In the microfcope the leaves are 
of a tortoife-lhell tranfparency and colour. It is found in a bed 
of ruddy fpeckled granite, to which it adheres '. 
N°. ii. A much more beautiful foliaceous talc I have .rom a cliff 
near the Lizherd, of extream thinnefs, fine texture, tranfparency, 
and filver hue : the leaves were in diameter but half inch down- 
wards, being broken fmaller than their natural fize be.ore I had 
them. It is the Mica particulis membranaceis jijjiltbus chap hams . 
N°. iii. A fpecimen of the fame kind of a browner, more corne- 
ous colour, lefs flexible, and its membranes larger . 
N°. iv. Radiated fllvery talc. In a bed of milk-white tabulated 
quartz. The rays are an inch and a quarter long and under, con- 
filling of feveral membranes of talc one-fourth of an inch long by 
one-fixth of an inch wide, in the Ihape of the leaf o. a peach- 
tree : they lie in ftraight lines, fpnnging as it were from a 
centre , rpi 
N°. v. The fhining gold-coloured talc, or mica aurea. 1 he 
micffi are of filver as well as gold-colour, but lefs diftinct ; neither 
of them elaftic : they lie longitudinally in parallel flakes, one on 
the back of another, and between them have white cryftallme 
fhivers ; but what part of Cornwall I had this from, I do not 
recollect. 
SECT. VIII. 
Of the af- 
beftos found 
in Cornwall. 
Of the folid albeftine talc we have before taken notice, that it 
is fometimes found adhering to the pureft fpecimens o t e eatites 
Cornubienfa, or Soap-rock. The fame fubftance is fpread like an 
enamel on the furface of the rocks expofed to the fea. This is near 
of kin to the Ophites, or Serpentine marble of the ancients, and 
fometimes is but a thin film, a kind of enamel, ftiiver, or cruft; but 
where it is in larger and more ftony mafles, it admits a high polifti, 
is cut into various forms, and turned into vafes ra .. 
Of the fibrous abeftos I have a fample found in a ftone in the 
church yard of Landawinek, the filaments flat, pointed, of a bright 
purple colour, and filvery glofs, extremely fmall and flexile, appear- 
ing; in the microfcope edged with a foft down, the fibres longer and 
of a brighter hue, but not fo woolly as fome famples I have from 
the ifle of Anglefea. In greater plenty I have received fpecimens of 
h Huelanboys. 
1 It feems the Mica particulis fquatnofts Jparjls 
of Linnaeus. Syft. Nat. page 159. 
* Linnaeus Syft. Nat. ib. ^ 
k From Gwenap. 
1 From Bellchapel work, in Gwenap. 
m This fhould be the Ollaris folidus virefcens, 
maculofus polituram admttms of Linnaeus, page 160, 
N°. iii. 
an 
