Historically, malicious spirits were blamed for poltergeist activity. According to Allan Kardec, the founder of Spiritism, poltergeists are manifestations of disembodied spirits of low level, belonging to the sixth class of the third order. Under this explanation, they are believed to be closely associated with the elements (fire, air, water, earth). In Finland, somewhat famous are the case of the "Mäkkylä Ghost" in 1946, which received attention in the press at the time, and the "Devils of Martin" in Ylöjärvi in the late 19th century, for which affidavits were obtained in court. Samuli Paulaharju has also recorded a memoir of a typical poltergeist, the case of "Salkko-Niila", from the south of Lake Inari in his book "Memoirs of Lapland" ("Lapin muisteluksia"). The story has also been published in the collection of "Mythical Stories" ("Myytillisiä tarinoita") edited by Lauri Simonsuuri.