Justus von Liebig
Justus von Liebig c. 1860
|Died||18 April 1873 (aged 69)|
|Nationality||Hessian, then German|
|Alma mater||University of Bonn|
University of Erlangen
|Known for||Invention of nitrogen-based fertiliser|
Law of the Minimum
|Institutions||University of Giessen|
University of Munich
Liebig was one of the greatest chemistry teachers of all time. At 21 he was appointed professor of chemistry at Giessen, recommended by Alexander von Humboldt. There he established the world's first major school of chemistry. He invented the chemical laboratory, and used it for teaching. He founded and edited the Annalen der Chemie, the leading German-language journal of chemistry.
Liebig invented new methods for the analysis of organic materials. He showed that, to grow, plants need (as well as water and sunlight) carbon dioxide, minerals and nitrogen compounds. He discovered that nitrogen was an essential plant nutrient, and invented the first nitrogen-based fertiliser. His Law of the Minimum stated that a plant's development is limited by the one essential mineral that is in the shortest supply. He described the effect of individual nutrients on crops.
Where others thought that organic chemicals were entirely separate fron inorganic ones, Liebig thought diffferently:
- "...the production of all organic substances no longer belongs just to the organism. It must be viewed as not only probable but as certain that we shall produce them in our laboratories. Sugar, salicin (aspirin), and morphine will be artificially produced". Liebig's textbooks were the standard for many years.
In 1835 he invented a process of silvering that greatly improved the quality of mirrors.