Students of comparative folk-lore class all such manifestations under a common head, whether related of fairies or spirit mediums. They trace their origin to the same source whence come the notions of propitiating the fairies by euphemistic names. The use of such names as Jehovah, the Almighty, the Supreme Being, etc., for the terrible and avenging God of the Jewish theology, being originally an endeavour to avoid pronouncing the name of God, it is easy to see the connection with the exorcising power of that name upon all evil spirits, such as fairies are usually held to be. Here also, it is thought, is presented the ultimate source of that horror of profane language which prevails among the Puritanic peoples of England and America. The name of the devil is similarly provided with euphemisms, some of which--such as the Old Boy--are not of a sort to offend that personage's ears; and until recently the word devil was deemed almost as offensive as the word God, when profanely used.