Walnut gum (resin)

"When a walnut tree grows old and approaches death," wrote the great scholar from Khorezm, Abu Reyhan Muhammad ibn Ahmed al-Biruni (973-1048),"a year before that, a red gum, similar to corals, is released from it." This gum was used by ancient healers in the form of powders to heal skin ulcers and eliminate acute and burning rashes, as well as (internally) to remove stones from the bladder.