[There is] a well dedicated to St. Euinus, about sixty yards from the church of Redruth, at the foot of Carn Brea hill; and within the recollection of persons now living a stone cross stood near it. The peculiar virtue ascribed to this well was that whoever should be baptized by its water would be preserved from being ignominiously hanged.
p74 in Ancient Crosses, and Other Antiquities in the East of Cornwall By John Thomas Blight (1858). (readable online at Google Books). This is also known as St Euny’s Well, and is at SW690413.