Richmond times-dispatch. [volume] (Richmond, Va.) 1914-current, 1915-05-09


young lady. fresh from the realms OF
higher education. recently appeared at
the ONCE OF prominent manufactured
OF lead pencils, presented credentials
IS health department investigator.
and announced her desire to study con-
ditions in the factory with reference
TO lead poisoning. Just as Pigs Is
Pigs" so to her lead was lead such
literal mlndedncss is hardly TO be ex-
pected Of the average mortal, but If
the fair investigator had called 20 in
0uire as to the actual nature OF the
product made and just why II had 10
share names with something equally
common, but totally different. the mem
Dry OF her visit would have been less
likely to have been perpctuated in the
Suise OF the traditional factory joke.
Most persons are aware that lead
pencils are not made OF lead, but that
the so-called black lead in them is "a
fun brother To coal and TO the aris,o-
cratic diamond. and that 1t is Identical
with many other substances in COM
mon use. such as the backing on the
kitchen range, arc additional facts not
nearly so we'll known. \ recently in
stalled exhibit In the National Mu-
seum's division OF mineral technology
shows the various forms Of graphite.
including natural and manufactured,
as we'll as the various ingredients
used In this industry.
Black lead and plumbago are popu-
lar terms for form OF pure carbon
whose proper name, graphite. from the
Greek word meaning to write. is more
accurate and more appropriate. AS Il
mineral from the earth. IL has been
known and used since about the middle
OF the sixteenth century: but for a
matter Of 200 years thereafter the con-
a. nf Gel u.iyh rafa 70
its true nature seem TO have remained
about on par with those of the fair
visitor at the pencil factory. Accord
ingly, while pencils made OF IL were
in use. as far back as 1868. CORVALLIS
surrendered. cl2 years later, before he
could have known that this soft. black.
greasy mineral might be burned. and
that in burning II vanished from view
in the form OF carbonic acid gas. just
like so much charcoal. Meanwhile. in
lieu of any regular name. various nick
names were assigned, originating in
superficial rescmbiances TO better
known substances. Two OF these nick
names. black lead and plumhago. out
srowths OF the fact that lead is soft
and when furnished will leave a black
streak on paper, have persisted.
Graphite occurs rather frequently in
granite rock throughout the Appa-
lachian system from Maine TO Texas.
and has been mined in various locali-
ties. notably at Ticonderoga, In New
York, and at A number Of points In
Pennsylvania and New Jersey. But the
Appalachian range of occurrences. and
with them those of Canada. consist
of disseminated grains known to the
trade fake graphite and the cost
Of recovery has pretty generally proven
prohibitive. with the result that even
the old Ticonderoga Mines are no
longer operated. For a number OF
years the chief supply of natural
graphite has come from Ceylon, where
the mineral occurs as massive veins.
Another prominent graphite field lies
in the Tunkinsk Mountains. OF Siberia
and Mexico also has a rather important
source in Sonora. In this country,
Montana has the only occurrence, other
than of flake graphite. thus far en-
countered.
Ofhand there seems 20 he something
homogeneous in the thought of carbon
being at once the most typical of COM
bustibles, and the best-known fire re-
sistor, but such is the case: for the
Kitchen range, which is fed with car
bon in the form of coal, is blacked
with carbon In the form OF grphite.
The answer lies in the fact that the
purer and denser the carbon, the less
infiammable it becomes. Thus. just as
anthracite coal is less readily COM
bustible than bituminous coal with it's
high percentage OF gas-forming in
called graphitized anthracite. notably
In Rhode Island. which Is so dense that
II will not support combustion prac-
ticably, and true graphite. in its en-
trcme of density, is almost incombust-
able. Moreover, 1t does not melt at any
attainable temperature, so is peculiar
! ~ fitted to withstand great heat.
AS q matter of fact, few people begin
to realize the range OF uses to which
graphite is put: for it is an essential
though minor ingredient In a great
! number OF unsupported connections AS
common as that Of lead pencils. with
many of these the graphite man is
himself unfamiliar, beyond the simple
| fact that this or that manufacturer
| purchases from him; for In such uses
| 1t Is apt 10 represent part OF a secret
| process. Lead pencils. lubricants. cleo
| trical conductors and black polishes
| and paints arc prominent conventional
| uses; but 1t is liable to he present
| pretty much anywhere that antifriction,
unfading blackness. heat resistance,
| electrical conductivity or nonccrrosive-
, ness are desirable properties. and the
| fact that without graphite the derby
hat rs we know 1t could not be. is an
A