A quick nitpick, pencils don't actually contain lead (Pb). Pencil "lead" is just graphite + clay. Actual Lead pencils died out in the early 20th century. Techni

A quick nitpick, pencils don't actually contain lead (Pb). Pencil "lead" is just graphite + clay. Actual Lead pencils died out in the early 20th century. Technically "last century" though.