Friedrich Wöhler
Wöhler (1800-1882)[12] was the son of a Hessian agronomist and veterinarian, and he grew up near Frankfurt. After attending the Gymnasium there, he entered Marburg University in 1821 with the intent of studying medicine. His passion from early childhood, however, had been chemical experimentation and mineral collecting, and Ferdinand Wurzer's lectures did not attract him. Accordingly, he transferred to Heidelberg to study with Leopold Gmelin. But Gmelin judged that Wöhler already knew too much chemistry to profit from his courses; he advised Wöhler to study with Berzelius after receiving his M.D. de-
gree. In the fall of 1823, upon receiving a favorable response to his inquiry from Stockholm, Wöhler took this step. It determined the course of his life.
Wöhler not only learned Berzelian techniques in his year in Stockholm, he also learned fluent Swedish and formed an extremely close friendship with the older Swede that lasted until Berzelius' death. Berzelius eventually urged the familiar form of address upon his student—for the time, an unusually strong mark of regard of an older for a younger man. Back in Germany, Wöhler sought habilitation at Heidelberg, but was instead hired for the new Berlin Gewerbeschule (trade school) at a salary of 400 thalers. Three years later, he had become a highly respected chemist and was earning 1200 thalers.[13] By this time he had also become Berzelius' viceroy in Germany by translating and editing the German editions of Berzelius' Jahresberichte and Lehrbuch —an average of about one and a half large volumes of text per year for over twenty years.
Late in 1831 Wöhler accepted for personal reasons a call to the newly founded Technische Hochschule (Institute of Technology) in Kassel at a diminished salary of 800 thalers plus free rent. There he continued the experimental work that he had begun so well in Berlin. Wöhler's work on cyano compounds, beryllium, yttrium, and aluminum had already brought him fame; his synthesis of urea in 1828 was particularly dramatic, in its implications both for organic synthesis and organic isomerism. Wöhler's models were the sober empiricist Gmelin and the incomparable Berzelius; he was a superb and enormously prolific experimental chemist. Disinclined toward philosophy or even chemical theory, Wöhler fit in well with the rationalist and practical traditions of the Berlin Gewerbeschule and Kasseler Technische Hochschule and, later, the University of Göttingen. He impressed everyone with his kind and unassuming character. In their correspondence, he and Berzelius often ridiculed the Naturphilosophen and the Hegelian philosophers.[14]
Wöhler first met Liebig in 1825, and the two young chemists always seemed to be stepping on each others' toes in their research during the middle to late 1820s. To avoid future problems, in 1829 they began to collaborate occasionally on topics of interest to both of them. By this time they were already close friends, and they maintained this friendship until Liebig's death in 1873. Wöhler learned from Liebig the newly improved method for elemental organic analysis one year after Liebig developed it in the fall of 1830.[15] When Wöhler suffered the death of his young wife in 1832, Liebig invited him to Giessen for companionship and for the distraction from grief that hard work could offer.[16] This was the period in which the two chemists completed their
work on the benzoyl series, an article that galvanized the chemical world and is usually regarded as the best single contribution of either Liebig or Wöhler.
In the spring of 1836, Wöhler transferred to Göttingen as Stromeyer's successor. Gmelin had declined the offer, and Wöhler, supported by Gmelin and Berzelius, was preferred over his close rival and friend Liebig. Liebig wrote Wöhler that he, like Gmelin, would have declined, but regretted that he did not get the offer to use to good effect with his administration.[17] Stromeyer had inherited from J. F. Gmelin a small but well-equipped teaching and research laboratory on the ground floor of an old but spacious dwelling; a director's residence was provided upstairs. Shortly after his arrival, Wöhler wrote Berzelius describing many details, quite pleased with his new environs.[18] He quickly became an ornament of the faculty and taught a phenomenal number of students during his forty-six year tenure there.
Since soon after his arrival in Göttingen Wöhler provided Kolbe with his first detailed introduction to chemistry, and since Wöhler's early teaching career has never been closely studied, a discussion of the latter is warranted. Every semester Wöhler taught general theoretical (inorganic) chemistry at 9:00 A.M. six days a week and a laboratory practicum every Monday, Tuesday, Thursday, and Friday at 11:00 to 1:00. In the summer semester he also taught pharmacy Monday through Friday at 6:00 A.M. Advanced students were allowed to work all day every day in the lab. He used the laboratory left him by Stromeyer, although he reappointed it in "Berzelian" style during his first semester and refloored and repainted it two years later. It appears that Wöhler had reasonable demand for his lectures and practicum during his first two years, but precise numbers and names are not available.[19]
Whatever the initial numbers were, Wöhler's correspondence provides evidence for a noticeable increase in his enrollments beginning in summer semester 1838—coincidentally, the semester that Hermann Kolbe entered the university. Although exact information is sketchy here, too, we do know that he had twenty-eight students taking the practicum by the spring of 1840 and forty by the end of 1841, a remarkable level that continued to be maintained thereafter. After the influx started, it appears that Wöhler began to assign special projects to his most advanced students, investigations that might yield publishable results. There is no evidence that he ever did this in Berlin or Kassel, although it appears that he did have a practicum in Kassel.[20] The first Wöhler pupils whose names appear as authors of published papers were pharmacy students: August Stürenburg and Friedrich Weppen, who enrolled at Göttingen in May 1838, and Georg
Schnedermann, who came in the fall of 1839. Apparently all were from bourgeois Hanoverian families. Schnedermann worked with Wöhler for no less than six years, published a number of short papers, and became Wöhler's assistant in his last semester. The first Wöhler chemistry Ph.D. was earned by Friedrich Carl Voelckel, the son of a Bavarian merchant, who enrolled for summer semester 1839 and received his degree three years later. He later became professor of chemistry in Solothurn, Switzerland.[21]
In these early years, Wöhler's approach to publication of his student's work varied according to its significance and the student's precise role. He did not hesitate to use student results in his own papers, often without even naming the student, if the work was simply straightforward or mechanical assistance. If more skill or persistence had been needed, Wöhler was careful to acknowledge the assistance by name. Finally, there are a few examples in these years of Wöhler supervising what was essentially independent original research, and in such cases, the student published in his name alone.[22]
From 1838 until 1841, Wöhler appears to have had only a very small number of these select advanced students working on such projects at any given time—one, two, or three per semester. By summer semester 1841—again, ironically, the very semester Kolbe became an all-day Praktikant—a real research cohort of eight advanced workers emerged for the first time. In addition to Kolbe, Voelckel, Schnedermann, and Weppen, the group included the medical students Otto Griepenkerl and August Vogel and the philosophy students August Beringer and Wilhelm Knop.[23]
The pattern for the future was now set. Wöhler's increasing popularity and fame, and the rising profile of the chemistry profession itself, ensured that Wöhler would have substantial and rising enrollments ever after. Having inherited Stromeyer's assistant, H. A. Wiggers (later professor of pharmacology at Göttingen), Wöhler successfully petitioned for a second (Schnedermann), hired for the winter semester 1841/42, to help him with the now heavy numbers. That semester he had another increase, now past forty Praktikanten, more than the space could really accommodate. No fewer than fourteen of these men were doing advanced projects and working not just the scheduled four or eight hours per week but morning to evening in the lab. The number of these advanced Praktikanten, however, seems to have been rather variable, for in winter semester 1843/44 he had only three, while for each of the following two semesters the number jumped back up to twelve.[24]
Some additional information on Wöhler's students can be obtained from careful study of the Göttingen matriculation registry. During the
period before Kolbe left Göttingen (fall 1842), a total of twenty-one students can be identified who were known (or can safely be presumed) to have studied with Wöhler. Eight listed chemistry as their field of study; the third of these was Kolbe. Kolbe's preparation apparently was not as thorough—or his progress not as swift—as that of Voelckel or Schnedermann, who arrived slightly later but were earlier in publishing articles from the lab. Nonetheless, it is interesting to note that Wöhler's most famous student was also very nearly his first. The rest of these twenty-one Wöhler students from Kolbe's days in Göttingen are divided by discipline roughly equally among pharmacy, medicine, and philosophy.[25]
This cohort represents but a small fraction of the total number passing through Wöhler's lab during these years. The rest cannot be identified by name, but it is probable that they were mostly students of pharmacy or medicine. All told, the number of students who passed through his laboratory from his arrival in Göttingen until Kolbe left for Marburg six years later was probably between 100 and 200.
Early in the spring of 1842, ground was broken for a new laboratory extension in Hospitalstrasse, immediately adjacent to the old lab. Directed closely by Wöhler, construction of the "magnificent building" was completed by that fall; the two sections could now accommodate up to fifty workers.[26] (This building, since destroyed, sufficed until 1859-1860, when a completely new and much larger laboratory was constructed for the Chemical Institute.) Unfortunately, Kolbe could not personally enjoy the expanded facilities since he left Göttingen in the fall of 1842. He must have watched with interest, however, as the facility slowly rose and became fitted for chemical research, while working daily in the old lab that summer.