_210 
z 
- 
judgment may himself be liable to hid- 
den prejudices, unknown even to him-- 
self: he may be credulous or incredulous, 
arid in proportion as his character in- 
clines to credulity or incredulity, will the 
testimony given appear strong or weak. 
This defect, it is true, must affect at all 
times the judgments of fallible beings; 
but will be more notorious when applied 
to mathematical measurements of credi- 
bility. 
I fear, Sir, that I have already extend- 
ed my detdarks too far, aud shall’ there- 
fore conclude for the present. 
: Your's, &c. A. M. 
ee 
To the Editor of the Monthly Magazine. 
SIR, 
ERHAPS some of your intelligent 
Correspondents, so many of which 
your most useful publication can truly 
boast of, will be so good as tosay what 
pretensions the sons of peers or their 
near relatives have to the supporters used 
by their fathers? 
By inserting this, you will much ob- 
lige Your’s, &c. 
: A CONSTANT READER. 
February 27, 1808. 4 
——see a 
To the Editor of the Monthly Magazine. 
SIR, 
HE late introduction of nice as an 
article of manufacture, in the for- 
mation of those beautiful semi-pellucid 
vases, &c. now so much in fashion, calls 
to my mind the very great utility of tade, 
a substance extremely common in many 
parts. of Europe, and, I believe, not un- 
known as one of our mineral produc- 
tions: at least, I am very much mis- 
taken if I have not somewhere seen or 
read of specimens. of British talc. 
Towards the north of Hindostan, amidst 
the immense ranges of mountains, which 
separate the empire of Cubul from the 
Sek territory, talc is found in abundance, 
ded i all its varieties. The natives of 
those countries, kowey yer, do not put it 
to half the purposes for which it is so 
emimently quahfed; though they ex- 
port li in large masses and ip pow der. 
In the former shape, the scaistose talc 
is conveyed to Delhi, whence it finds its 
way into the provinces dependant on the 
East India Company, where the mer- 
chants sell it at various prices, from one 
rupee to six per seer of two pounds, ac- 
cording to the extent of the various la- 
mine of which it is composed: that 
which is of aclear pearl colour, and is of 
a size and shape suited to become asub- 
iP 
Properties and Use of Tale. 
[April 1, 
stitute for our English window-glass, 
(which bears a high price throughout In- 
dia, bemg i general use among Euro- 
peans, and partially so with the ‘natives 
of opulence) is the dearest. 
_ We consider tale as being large when 
the surface contains from one hundred to 
one hundred and fifty square inches. 
The solidity varies from four to six inches: 
it is composed of layers, which are easily 
divided ; and which, when the article is 
good, come off almost as level, and as 
free ces flaws, or scaley breaks, as panes 
of glass. By examining the edaes of the 
mass, it may be ascer tained, with tole- 
rable certainty, how the tale will split ; 
whence, with comnion precaution, and a 
proper guidance of the flat mstrument 
used on the occasion, the greater part 
may be applied to all the purposes of or- 
dinary glazing. 
Tule is not, however, perfectly transpa- 
rent; itis true, that objects may be dis- 
cerned through panes made thereof, but 
not with perfect distinctness. This, hoe 
ever, depends much on the brilliancy of 
the object, and on the light to which it 
may be exposed. 
One great inconvenience “iar in 
India, among those who inhabit glazed. 
houses, 1s, that, owing to the excessive 
heais, and eppemeny during the rainy 
season, when. the air is uncommonly 
damp, while the sun is equally powerful, 
window-frames .are apt to warp, and to. 
crack the glass, Further, when the sun 
shines on glass, or if any colour or object 
casting great heat, and causing much 
glare, be opposite, the reflection becomes 
intolerable! . 
On the contrary, talc, being far more 
elastic than glass, is never known to 
break from such causes: it resists much 
force; and, from its opacity, 1s peculiarly 
qualii fied to repel those rays which con- 
vey the light, and consequently the heat, 
(in such climates especially,) to the in 
terior. 
The greatest objection to talc is, that, 
in the course of a few months, it becomes 
of rather a darker colour than when first 
split: as thi takes place more especially 
during wet weather, we may. conclude 
that hydrogen affects it considerably; 
and that, if so soon as the ¢ale were split, 
a good transparent varnish were ap pirenty 
even the moderate change it is subject: to, 
from exposure, might: be prevented. 
I have bad a lantern made of falc, ' 
which was found to answer far better 
than glass, or horn; it not being subject 
to break like the former, nor to warp, or 
split, or burn, as the latter docs. This 
eurlous 
