David Unaipon-the man on the $50 note-was a most extraordinary person. An early Aboriginal political activist, he was also a scientist, a writer, a preacher and an inventor. In the 1920s, under contract to the University of Adelaide, he was commissioned to collect traditional Aboriginal stories from around South Australia. He also acted as a 'collector' for the Aborigines Friends' Association. Most of the stories come from his own Ngarrindjeri people,...