"There are some little stones which eagles often bring to Prester John's territories and which worn on the finger preserve or restore the sight, or if consecrated with a lawful incantation, make one invisible and dispel envy and hatred and promote concord. After a description of a sea of sand in which there are various kinds of edible fish and a river of tones, Prester John soon mentions the worms which in his language are called salamanders, who cannot live except in fire, and from whose skins he has robes made which can be cleansed only by fire."