What is Black Lead?
It is a kind of mineral, of a deep shining black or bluish color, soft and unctuous to the touch; it is insoluble in acids, and infusible by fire. Black lead has been found in many parts of the world, in a state of greater or less purity, but it is the English black lead which is the most esteemed.
Insoluble, incapable of dissolving.
Infusible, not capable of being melted.
Is Black Lead a proper term for this mineral?
No; because, in reality, there is not a particle of lead in it. On the spot where it is procured, it is called by two or three different names, but the most usual is Plumbago.
Where is the best Black Lead found?
The best and greatest quantity is found in England, in a mine near Keswick, in Cumberland. It is much used for pencils or crayons, for writing, drawing, &c.; for this purpose it is sawn into slips, and fitted into a groove in a strip of soft wood, as cedar, &c., over which another is placed and fastened with glue.
What is Platina?
A metallic substance, more recently discovered than the metals already described; and analogous to the perfect metals, especially gold,—many of whose properties it possesses.