Daniel Lorenz Salthenius

Daniel Lorenz Salthenius (March 16, 1701 – January 29, 1750) was a professor of theology at the University of Königsberg from 1732 until his death.
Salthenius was born in Markim between Stockholm and Uppsala, Sweden, the son of a Lutheran pastor. He studied at the university in his birthplace, as well as University of Halle, and became a noted Pietist. He was appointed to his post at Königsberg to help the Pietist cause there.
Salthenius's orthodox Lutheran opponents accused him of having made a pact with the Devil when he was a student in Uppsala. He wrote a letter in his own blood, asking the Devil to provide him with a bottomless bag of money in exchange for his body and soul, and placed the letter under an oak tree, where it was found by the local police. The letter is today kept at Uppsala University library. 
However, Salthenius was not dismissed from the university and remained a full professor.