This is the
sign for realgar, a
compound of sulphur and arsenic, a ruby-red paste used in the
production of glass, small shot, signal lights, grounding paint for
ships' hulls, etc. It was a substance that the alchemists worked
continuously with during the Middle Ages. Note that sulphur
could be drawn and arsenic , two signs which have been combined in this.
Realgar was also drawn , , and .