Plumbago graphite It actually leaves a blackish level somewhat like lead See Graphite
- used as a lubricant so when a moderator in nuclear reactors
- Plumbago; graphite. It will leave a blackish level notably like lead. See Graphite.
In 1778 he proposed a new method of making calomel and powder of algaroth, and he got molybdic acid from mineral molybdaena nitens which he carefully distinguished from ordinary molybdena (plumbago or black lead of commerce).