Who is Dr. Tholuck from Autobiography of George Muller and what is their importance?

Dr. Tholuck was a professor of divinity at Halle. Through Tholuck, Muller became acquainted with other devoted Christians. Dr. Tholuck also helped Muller find work as a German tutor when his father disowned him. Tholuck also wrote a letter to the missionary society on Muller's behalf, helping him to find a place in missions.