Which of the following is NOT one of the many contributions of Louis Pasteur?

Louis Pasteur was a French chemist and microbiologist who was one of the most impoant founders of medical microbiology. He is remembered for his remarkable breakthroughs in the causes and prevention of diseases. He created the first vaccines for rabies and anthrax. His experiments suppoed the germ theory of disease. He also invented a method to treat milk to make it free from disease causing bacteria, a process that came to be called pasteurization. Ref: Park, 21st Edition, Page 5.