Letter from Justus Liebig, President of the Bavarian Academy of Sciences, Munich, to LB Thudichum Liebig was one of the foremost chemists of his age, making important contributions to agricultural and biological chemistry. He discovered that plants feed on the nitrogen and carbon dioxide in the air, as well as on minerals in the soil. One of his most famous accomplishments was the invention of nitrogen-based fertilizer. The envelope is addressed to "LB Thudichum" - most likely a shortened form for JLW Thudichum as the address on the envelope is the same as that for MM/1/1. Thudichum worked as Liebig's research assistant in the University of Giessen, 1847-1850. After Thudichum moved to London in 1853, he carried out research into the chemical constituents of the brain Although a controversial figure in his lifetime, Thudichum has been posthomously hailed as "the first English biochemist". 6 March 1870