Random Facts #28 · 9:19pm Mar 3rd, 2017
The "lead" in pencils is actually a mixture of clay and graphite.
Speaking of pencil lead, if you put a piece in an airtight jar, or better yet, a vacuum chamber, and connect a 12 volt power supply or battery to it, it'll glow a bright yellow-red. (Congrats for building a lightbulb and not burn your fingers off!)
There are ancient books that have been discovered to be bound using human skin.
I actually knew that about pencils :D (The first thing not the second.)