Today 222 years ago, on May 12, 1803 (March 22, 1803 in the lunar calendar), German chemist Liebig was born. Justus von Liebig (1803-1873) Famous German chemist. Born May 12, 1803 in Darmstadt, Riesen, Germany. His father was a businessman of inorganic salts and pigments, and he used these things to conduct chemical experiments in his spare time, so Liebig was led into the field of chemistry from an early age. In 1822, he received his doctorate from the University of Erlangen. A series of studies on the compounds of fulminic acid were completed in Paris in 1824. After returning from Paris to become a professor of chemistry at Giessen University, he immediately embarked on an unheard-of plan, that is, to reform the traditional chemistry education system and teaching methods in Germany and explore ways to bring up a new generation of chemists. Liebig compiled a brand-new syllabus for laboratory teaching, which stipulates: At first, students should do experiments while studying the lecture notes, first use known compounds for qualitative and quantitative analysis, and then purify and identify new compounds from natural substances, as well as inorganic and organic synthesis; After completing this course, conduct independent research as a graduation thesis project under the guidance of a tutor; Finally, he obtained his doctoral degree through appraisal. Liebig's teaching system, which allows students to gradually shift from systematic training to independent research in the laboratory, was not recognized by people before him, but it laid the foundation for the modern chemistry education system. The establishment of the Giessen laboratory, the compilation of the chemistry syllabus and Liebig's enthusiastic and rigorous scholarship made the chemistry education movement develop with greater momentum and far-reaching influence in Germany than anywhere else, thus attracting students from all over the world to Giessen University and gather under Liebig's door. Under the careful guidance of Liebig, a large number of world-famous chemists were trained through systematic training in the laboratory. Among them, Hoffman, who laid the foundation for dye chemistry and dye industry, Wu Ci, who discovered the interaction of alkyl halides and sodium metal to prepare hydrocarbons, Kekule, who put forward the theory of benzene ring structure to lay a solid foundation for organic structure theory and was known as "chemical architect", and Voskresensky, who was praised by Mendeleev as "the father of Russian chemists", etc. It is worth pointing out that these students also followed Giessen's practice in their own countries and set up a number of teaching laboratories for students, which actively promoted Giessen's chemistry education model all over the world, trained many famous chemists, and formed the Giessen-Liebig School, which made great contributions to the development of world chemistry. He made many major contributions to basic chemical principles, and later turned to the study of biochemistry and agricultural chemistry. In biochemistry and agricultural chemistry, Liebig studied the chemical principles of fermentation and spoilage. He applied chemistry to agricultural production, put forward the mineral nutrition theory of plants, determined the chemical principle of fertilization to restore soil fertility, and advocated the use of inorganic fertilizers to supplement other elements in the soil that may be depleted.