What is the name of the german scientist whose law says that the affliction known as the "royal disease" is carried by women, but affects only men?

The German scientist who is responsible for stating that the Royal Disease, known as hemophilia, occurs only in men, is called Friedrich Hopff, who was a student at University of Zurich and was the first to coin the term, which was then known as haemorrhaphilia. He conceptualized this while collaborating with his professor, Dr. Scholein.