Robert Bunsen

Bunsen (1811-1899)^[41] was the son of a professor of modern languages at the University of Göttingen. He studied the sciences there, completing his Ph.D. under Stromeyer in 1831. From the beginning of 1832 to the fall of 1833, he traveled on a government grant in Germany, France, and Austria, seeking especially to investigate practical, technical, and geological subjects. A nine-month residence in Paris enabled him to learn from Gay-Lussac, Dumas, Chevreul, Pelouze, Regnault, and others, and he had the good fortune to spend a month in Giessen just when Wöhler and Liebig were collaborating on their benzoyl work. He also visited Mitscherlich and the Rose brothers in Berlin. On his return home, he habilitated at Göttingen, teaching technical chemistry and stoichiometry. Upon Stromeyer's death (18 August 1835) he took over the general lectures and the laboratory practicum. In the spring of 1836, he was appointed Wöhler's successor at the Kassel Technische Hochschule at the reduced salary of 650 thalers.^[42]

Even before his transfer to Kassel, Bunsen had begun to establish an enviable research reputation. His papers merited favorable mention in Berzelius' Jahresberichte from 1835 on, and that fall he had the pleasure of accompanying Berzelius on a journey from Kassel to Göttingen.^[43] From the late 1830s Berzelius began to extol Bunsen's work in the highest terms, both for its technical virtuosity and for its relevance to Berzelius' theoretical positions.^[44] Bunsen later described Berzelius as "my truest friend and counselor."^[45] To the extent that he had any theoretical commitment it was thoroughly Berzelian, maintaining the Swede's notational and formula styles to at least the 1880s, long after all others had abandoned it.^[46]

In Kassel, Bunsen Continued' to teach students in the small and primitive laboratory inherited from Wöhler and began what were to become world-famous researches into eudiometry and the cacodyl radical. His growing eminence led to his call in 1839 to the University of Marburg, initially as Extraordinarius (at 650 thalers) but raised to the Ordinarius rank (800 thalers) two years later. His predecessor, Ferdinand Wurzer, had since 1811 been teaching selected students in his laboratory, but had done so according to the older pedagogical pat-

tern, namely, on a small scale and on the basis of personal patronage. Wöhler, who spent a semester studying with Wurzer before transferring to Heidelberg, had found him intolerably old-fashioned.^[47]

By contrast, in the spring of 1840 Bunsen initiated a chemical practicum in the consciously "modern" (Liebig-Wöhler) style, namely, in the words of Christoph Meinel, a "planned, didactically self-contained, and consistently structured unit of instruction." Moreover, the practicum was publicly advertised in the university course list, and the professor took a standardized fee for it.^[48] The course was advertised as eight hours a week during precisely the same hours as Wöhler's practicum at Göttingen, but well-motivated students had no trouble persuading Bunsen to allow them to work all day every day. Bunsen was also careful to remit all fees for students who could not afford them—or even for those students who were exceptionally well motivated, regardless of their means.^[49] In 1852 he was called to Heidelberg as Leopold Gmelin's successor, and there he formed the nucleus of what was the liveliest academic chemical community—though not a "school" in the usual sense—in all of Germany until the 1860s.

Bunsen was a man of uncommon benevolence, kindness, and humor, universally admired by his peers and revered by his students. He had a straightforward practical and empirical orientation, was sensitive to technological implications of his work (without, on a point of principle, ever taking out a patent), and was uninterested in theory to a degree bordering on outright hostility. There is probably no great chemist in history who was more averse to hypotheses and theoretical structures of all kinds, nor one more skilled in laboratory operations. After his great cacodyl investigation, which ended in 1841, he never returned to organic chemistry; later in Heidelberg, he totally excluded this field from his activities. His students and biographers have plausibly suggested that his aversion to organic chemistry was directly related to his aversion to theory, for it was just at the time of his one and only sizable organic-chemical project that organic chemistry became and remained intensely theoretical—and correspondingly, intensely disputatious, a quality that was also anathema to the gentle Bunsen.^[50]

Another significant gap in Bunsen's career appears to have been directly related to his theoretical aversion: he never founded a school, despite his eminence and despite teaching a phenomenal number of students over no less than sixty-five years. Indeed, testimony from many sources agrees that he lavished his greatest attention on beginners and that once the tyro began to show initiative and independence, Bunsen lost interest in further guiding him. In Heidelberg, Privatdozenten were not directed or counseled by Bunsen, nor were they even allowed to work in his university facility. Instead, they were

forced to cobble together improvised labs in their lodgings or in specially rented spaces. This was due less to lack of consideration by Bunsen than to his adamant refusal to create a coherent chemical school. It was enough for him to continue to induct new members into the fraternity of academic chemists and to pursue his own always fruitful research agenda in physical, inorganic, analytical, and geological chemistry.^[51]