20. Antoine Laurent Lavoisier

                      Antoine Laurent de Lavoisier (also Antoine Lavoisier) was born on 26 August, 1743 in Paris France. He is known as "The Father of Modern Chemistry". He was a French nobleman prominent in the histories of chemistry and biology. He stated the first version of the law of conservation of mass, recognized and named oxygen (1778) and hydrogen (1783), abolished the phlogiston theory, helped construct the metric system .
                  He wrote the first extensive list of elements, and helped to reform chemical nomenclature. He discovered that, although matter may change its form or shape, its mass always remains the same.
                  He was an investor and administrator of the "Ferme Generale" a private tax collection company; chairman of the board of the Discount Bank (later the Banque de France); and a powerful member of a number of other aristocratic administrative councils.
                 All of these political and economic activities enabled him to fund his scientific research. At the height of the French Revolution, he was accused by Jean-Paul Marat of selling watered-down tobacco, and of other crimes. He was guillotined on 8 May, 1794. 
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