This form of cross is sometimes called St. George's
(as is in an above entry). St. George was a
Christian officer in the Roman army who came to Lydia, where he
discovered that the people were being terrorized by a dragon. This
dragon subsisted on human flesh of young girls, and had at that time
just demanded the king's daughter as his next meal. George killed
the dragon, but was then beheaded by the king because he had persuaded
the queen to convert to the Christian faith.
The crusaders were so impressed by this exhibition of passivity and humility on the part of an expert warrior that they chose George as their saint and protector. The medals of various orders often carry St. George's crosses. In alchemy has sometimes been used to signify arsenic, also drawn and otherwise. See in Group 54 for more signs for arsenic.
Compare with in Group 30.