Compendium of Materia Medica

Okay kiddo, a compendium of materia medica is a big book that has information about different kinds of plants, animals, and minerals that can be used in medicines. It tells you what each thing can be used for, how it's made into a medicine, and how much to use. It's like a big encyclopedia of medicine ingredients! People have been making these books for a long time, because they need to know how to help sick people. It's like having a big box of tools for fixing things, but instead of hammers and screwdrivers, it has natural ingredients inside that can help make people feel better!