The Pulaski citizen. [volume] (Pulaski, Tenn.) 1866-current, 1881-06-02
40 aAs.1aN A-asaa
LEAD-PENCILS.
eDlaek Lead0 Not lead al AII-HOw PEN
S.fIs Arc Made.


Probably there is nothing so univer-
sally familiar In use, and also so utterly
unknown TO the users IN its nature and
origin as the +-3mmon lead-pencil, the
consumption nf It in this country alone
being estimated by the most competent
suthority at seventy-eight millions per
year. Its very name, perpetuating the
old leaden pl1mmet familiar among the
treasures of the boys first pocket, is
misnomer and mistake, .'black lead :"
having no more resemblance to lead
than chalk has to cheese Most people
suppose the "lead - is melted and poured
into the hole In the pencil wood, but it
is ground to an almost inpalpabie
powder, mixed to a paste with water,
made into a long coil like wire by being
forced through a small hole Gust as
water issues from a syringe), straightened,
and cut in lengths and baked like pot
terry. The "hardness" is due to an
admixture of clay. The pencil is made
in two halves by machinery at cheap
and rapid rate, and the processes, which
cannot be related here at length, are
among the most interesting In American
factures The material called "black
lead" is as marvellous as India rubber,
although less protean. 1t Is simply
carbon, and Is an enigma and bundle
of inconsistencies. Its unhkeness to
lead is suggested by saying that its
weight is less than one-fourth that of
lead, and that while lead fuses at low
temperature, graphite Is not friable at
any temperature known; on the contrary,
no substance known surpasses it In re-
sisting heat. Carbon in ordinary Anthra-
cite burns; carbon In graphite, refuses to
1,,,-,, A ov,, oih1a Of c1-a1l1ita huria6 tn
the top IN a mass of burning anthracite
carbon in carbon-not only refuses to
burn, but naelts its metallic contents.
The diamond, as is commonly known, is
nearly pure carbon; but so is graphite.
The latter is the softest substance dug
from the earth; the diamond is the hard
est substance known. Subject the dia-
mond to sufficient heat, and it parts with
mysterious something, leaving bit of
soft and dissimilar carbon; but 1t has not
yet-unless we accept recent stories
been found possible to reverse the pro
cess and add to the carbon that myster-
ious something. The purity of graphite
is extraordinary. It is sometimes refined
until less than one-twentieth of one per
cent of other matter than carbon Is left
merely trace. The finest specimen
of gold ever found, probably, was one
from the Ural Mountains, which was
1896 per cent. fine, thus having 1.04
per cent. of foreign substance, against
0.20 per cent. in the finest graphite; or,
stating it in another way, the finest gold
had more than Eve times, and the aver
age gold produced has twenty to fifty
times as much impurit as the finest
Ticonderoga graphite. Assuming that
the diamond is perfectly pure carbon,
this mere trace of impurity is all that
separates the rare, hard, translucent,
costly diamond from the common, exces-
sively soft. dull, comparatively valueless
graphite, scarcely one-haf as heavy as
the gem; and yet the two are closely
alike and almost equal in their resistance
to fire. How these things are so is yet
among the secrets of natures laboratory