Jeremias Benjamin Richter, German chemist, late 18th century.
© Science Museum / Science & Society Picture Library
Jeremias Benjamin Richter (1762-1807) studied mathematics, and philosophy under Immanuel Kant. His 1785 dissertation for his doctoral degree was on the use of mathematics in chemistry. Richter's most significant contribution to chemistry was his discovery of the law of equivalent proportions, which he called stoichiometry. He defined this as the "art of chemical measurements, which has to deal with the laws according to which substances unite to form chemical compounds." Illustration from 'Das Buch Der Grossen Chemiker, Band I' , by Gunther Bugge, published in Berlin, c 1929-1930.