Johann Wolfgang Döbereiner was a German chemist born on December 13, 1780. He is best known for his work in the early 19th century, particularly for developing the concept of triads in chemistry. Döbereiner observed that certain groups of three elements had similar properties and that the atomic weight of the middle element was approximately the average of the other two. Döbereiner's research laid the groundwork for the later development of the periodic table by Dmitri Mendeleev. His contributions to chemistry also included advancements in the understanding of hydrogen and the invention of the Döbereiner's lamp, an early type of lighter that used hydrogen gas.