The 2 symbols seen on pirate flags & bottles of poison
[DOC] [TLE] A Story of Poisons, Pirates and Mr. Yuk - SitePoint [PAR] Feb 6, 2015 ... A Story of Poisons, Pirates and Mr. Yuk ... Of course, by the 1700's  as the 'Jolly 
Roger'  we saw the symbol used on pirate flags.