Justus Liebig

Justus Liebig (12 May 1803 – 18 April 1873) was a German chemist who made major contributions to agricultural and biological chemistry, and worked on the organization of organic chemistry. 
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:
In 1835 he invented a process of silvering that greatly improved the quality of mirrors.
Liebig also developed a manufacturing process for beef extracts, and founded a company, Liebig Extract of Meat Company, that later trademarked the Oxo brand beef cube.
Liebig's work was closely followed in Britain, and he was awarded the Royal Society's Copley Medal in 1840. His own country made him a Baron in 1845.