In the oldest of the rocks there are beds of graphite, from which lead pencils are made.
Close to the filament is a graphite disk which serves as one of the electrodes.
In some instances, as in the case of graphite, the mixture may be merely mechanical.
The use of graphite did not become general until about 1850.
The graphite is recovered by mechanical processes of sorting.
Lucky there is plenty of graphite to be had, or wed be stuck.
It is crystallized, but this can be said of graphite as well.
(d) Rub the back of the tracing with graphite (the lead of the pencil).
Other forms substitute an equal weight of litharge for the graphite.
This process is only applicable to the hard varieties of graphite, as that of Ceylon.