Bunsen Burner Day commemorate the anniversary of the birth of German chemist Robert Wilhelm Eberhard Bunsen who was born 30 March 1811. After attending school in Holzminden, Bunsen matriculated at Göttingen in 1828 and studied chemistry with Friedrich Stromeyer as well as mineralogy with Johann Friedrich Ludwig Hausmann and mathematics with Carl Friedrich Gaus After obtaining a PhD in 1831, Bunsen spent 1832 and 1833 traveling in Germany, France, and Austria; and net many scientists along the way including Friedlieb Runge (who discovered aniline and in 1819 isolated caffeine), Justus von Liebig in Giessen, and Eilhard Mitscherlich in Bonn
In 1833 Bunsen became a lecturer at Göttingen and began experimental studies of the (in)solubility of metal salts of arsenous acid. His discovery of the use of iron oxide hydrate as a precipitating agent is still today the most effective antidote against arsenic poisoning. This interdisciplinary research was carried on and published in conjunction with the physician Arnold Adolph Berthold. In 1836, Bunsen succeeded Friedrich Wöhler at the Polytechnic School of Kassel (German: Baugewerkschule Kassel). Bunsen taught there for three years, and then accepted an associate professorship at the University of Marburg, where he continued his studies on cacodyl derivatives. He was promoted to full professorship in 1841. While at University of Marburg, Bunsen participated in the 1846 expedition for the investigation of Iceland’s volcanoes.
Bunsen’s work brought him quick and wide acclaim, partly because cacodyl, which is extremely toxic and undergoes spontaneous combustion in dry air, is so difficult to work with. Bunsen almost died from arsenic poisoning, and an explosion with cacodyl cost him sight in his right eye. In 1841, Bunsen created the Bunsen cell battery, using a carbon electrode instead of the expensive platinum electrode used in William Robert Grove’s electrochemical cell. Early in 1851 he accepted a professorship at the University of Breslau.
In late 1852 Bunsen became the successor of Leopold Gmelin at the University of Heidelberg. There he used electrolysis to produce pure metals, such as chromium, magnesium, aluminum, manganese, sodium, barium, calcium and lithium. A long collaboration with Henry Enfield Roscoe began in 1852, in which they studied the photochemical formation of hydrogen chloride (HCl) from hydrogen and chlorine. From this work, the reciprocity law of Bunsen and Roscoe originated. He discontinued his work with Roscoe in 1859 and joined Gustav Kirchhoff to study emission spectra of heated elements, a research area called spectrum analysis. For this work, Bunsen and his laboratory assistant, Peter Desaga, had perfected a special gas burner by 1855, which was influenced by earlier models. The newer design of Bunsen and Desaga, which provided a very hot and clean flame, is now called simply the “Bunsen burner”, a common laboratory equipment.
In 1859, Kirchhoff suggested that Bunsen should try to form prismatic spectra of the colors of heated elements colors. So Kirchhoff and Bunsen created a prototype spectroscope. Using it, they were able to identify the characteristic spectra of sodium, lithium, and potassium. Bunsen proved that highly pure samples gave unique spectra. Using this method he also detected previously unknown new blue spectral emission lines in samples of mineral water from Dürkheim. This indicated the existence of an undiscovered chemical element which he named “caesium”, after the Latin word for deep blue. The following year he also discovered rubidium, by a similar process. In 1860, Bunsen was elected a foreign member of the Royal Swedish Academy of Sciences for his Pioneering work in the field of Photochemistry organoarsenic chemistry and Scientific Research. The Bunsen–Kirchhoff Award for spectroscopy is also named after Bunsen and Kirchhoff.