Occasionally possession is not attributed to demons, but to deceased men who come by night from their graves, and suck the blood of their victims, whereupon the latter begin to decline and finally die a miserable death, while the buried man lives and thrives upon his ill-gotten food. This is vampirism, the name being derived from the once universal belief that there existed vampires, huge bats, who, whilst fanning sleeping men with their soft wings, feasted upon their life's blood and only left them when they had turned into corpses. Popular credulity added a number of horrid details to the general outline, and believed that the wretched victims of vampirism became themselves after death vampires, and thus forever continued the fearful curse. It was long thought that vampirism was known only to the nations of the Slavic race, but recent researches have discovered traces of it in the East Indies, and in Europe among the Magyars. Even the Sanscrit already appears to have had a term of its own for the vampires--Pysachas, "hostile beings, eager for the flesh and blood of living men, who gratify their cruel lust mainly at the expense of women when they are asleep, drunk, or insane." Careful writers like Calmet and others have, it is true, always maintained that, while the existence of vampirism cannot be denied, the phenomena attending it are in all cases the creations of diseased minds only. On the other hand, it is a well-established fact that the bodies of so-called vampires, when exhumed, have been found free from corruption, while in all the corpses around them decomposition had long since begun. In the face of such facts vampirism cannot be dismissed as simply the product of heated and over-excited imaginations, although it must be admitted that its true nature is still to all intents and purposes a profound mystery. According to popular belief the unusual preservation of the corpses indicates that death has not yet obtained full dominion over the bodies, and that hence the soul has not yet departed to its eternal home. A kind of lower organic life, it is said, continues, and as long as this lasts, the soul wanders about, as in a dream, among the familiar scenes of its earthly life and makes itself known to the friends of its former existence. The life thus extended requires blood in order to sustain itself, and hence the minds of those who come in magic contact with the soul of a vampire, become filled with sanguinary thoughts, which present themselves to their imagination as the desire to suck blood and thus lead to the actual performance. The fact that vampirism is epidemic, like many similar mental diseases, has led to the belief that the living are brought into close connection with the dead and are infected by them, while in reality there is no bond between them but a common misfortune. Nor must it be forgotten that in this disease, as in the plague, the mere thought of being seized often