 The notion that Vikings used A. muscaria to produce their <unk> <unk> was first suggested by the Swedish professor Samuel <unk> in 1784 . <unk> based his theories on reports about the use of fly agaric among Siberian shamans . The notion has become widespread since the 19th century , but no contemporary sources mention this use or anything similar in their description of <unk> . Muscimol is generally a mild <unk> , but it can create a range of different reactions within a group of people . It is possible that it could make a person angry , or cause them to be " very <unk> or sad , jump about , dance , sing or give way to great <unk> " . 
