Bencao gangmu
In addition to writing "Compendium of Materia Medica", Li wrote about gallstones, using ice to bring down a fever, and using steam and fumigants to prevent the spread of infection. Li also emphasized preventative medicine. He said that “‘To cure disease is like waiting until one is thirsty before digging a well...’” and listed over 500 treatments to maintain good health and strengthen the body, 50 of which he invented himself.