Introduction
The title of this book contains three entities: a quiet revolution, a man named Hermann Kolbe, and the science of organic chemistry. A few words of orientation are necessary about each of these subjects.
I use the phrase "quiet revolution" to denote a series of changes in chemical science during the 1850s, which centered on reforms of atomic weights and molecular formulas and on the subdiscipline of organic chemistry. Preparation for these changes began in the 1830s and 1840s with the work of Justus Liebig, Jean-Baptiste Dumas, Auguste Laurent, and Charles Gerhardt. The essential elements of this extended event included the following: the decline of Jacob Berzelius' electrically based theory of atomic-molecular combination, the rise of so-called type theories based on reactions wherein chlorine substitutes for the hydrogen of organic substances, the establishment of consistent ("two-volume") molecular magnitudes spanning organic as well as inorganic chemistry, the return from conventional chemical equivalents to a modified version of Berzelian atomic weights, and finally, the introduction of the theory of "atomicity of the elements," which led to what became known as valence and structure theory. The fundamental ideas of structure theory were delineated by August Kekulé in 1857-1858 and independently by A. S. Couper in 1858; they were given a particularly clear form and development by A.M. Butlerov from 1861. A largely equivalent and partly independent formulation of these ideas was due to Edward Frankland and Kolbe in 1857-1860.
There are a number of justifications for emphasizing the magnitude of these developments. Many quantitative indicators of the size and importance of the profession—number of chemists, number of chemis-
try students, number of journals, number of papers published, increase in technological applications, and growth of chemical industries—suggest an inflection point shortly after the middle of the century.[1] In the years before 1850, the discipline was well-developed and fully professionalized, but by any reasonable measure it was quite small in size and low in public profile. The situation was dramatically different a generation later. One example illustrating the change is the Deutsche Chemische Gesellschaft, which experienced phenomenal growth immediately following its founding in 1867. Within a few years, its Berichte ballooned in size from a thin volume in 1868 to giant and unwieldy tomes that required repeated subdivision. Another example is even more telling, namely, the total number of chemical compounds known. In 1860 there were about 3,000 well-characterized substances in the chemical literature; this number had grown steadily during the preceding several decades, with a consistent doubling period of about twenty years. But just about 1860 the trend dramatically accelerated, so that the doubling time thereafter was about nine years. It has remained so ever since.[2]
Also relevant is the centrality of organic chemistry in this revolution—nearly all of the new compounds just mentioned were organic—and the centrality of structure theory within organic chemistry. Events in the story center on the increasing ability of chemists to discern the internal arrangements of the atoms within molecules (what in the 1850s and 1860s were usually called molecular constitutions and what are today called structures[3] ). This theoretical knowledge went hand in hand with the new and ever more powerful ability to synthesize both familiar and novel organic substances. The new synthetic chemistry resulted in important applications in the production of dyes, pharmaceuticals, and other products of the burgeoning chemical industry of the late nineteenth century. Excluding such standard heavy industrial indicators as coal, steel, and railroads, the fine chemicals industry took the leading role in Germany, and it became increasingly dependent on the scientific investigation of chemical substances, especially organic compounds studied via structure theory. In summary, it can be argued that organic chemistry was the earliest pure science to have a massive impact on technology and on a national economy.
Thus, in both the theoretical and applied realms structure theory provided a virtually unlimited and highly fertile field for academic chemists. To use the Deutsche Chemische Gesellschaft as an example once again, the early volumes of the Berichte are packed with structure-theoretical investigations, far outweighing all other kinds of papers put together. The number of chemists rapidly expanded in the 1850s and 1860s, and the German states suddenly began to compete
with one another in building palatial laboratories, especially for organikers (events that are discussed below). By 1880 nearly all German universities had such institutes, and nearly all were led by organic chemists.[4]
If structure theory was vital for the growth of chemistry in the second half of the century, the Gerhardt-Laurent reforms were clearly the harbinger of structure theory. The reforms were proposed during a period of theoretical anarchy; both contemporary and subsequent commentators have emphasized the confusion that prevailed during this period. Water could be written HO, H O, H2 O, or H2 O2 , and in urging reform, Laurent and Kekulé each gleefully filled an entire page of text with currently defended formulas for acetic acid.[5] Four major concurrent systems of atomic weights and formulas, and many variations thereof, were widely accepted in the 1840s and 1850s.
Neither Laurent nor Gerhardt was able to produce strong new evidence for his views, and the situation was only clarified when Alexander Williamson (1824-1904) developed the first compelling experimental chemical evidence for the central element of the reform. Williamson's work (1850-1854) was followed by similar investigations by A. W. Hofmann, Gerhardt, Adolphe Wurtz, William Odling, and Kekulé; by the time of Gerhardt's death in 1856, the reform was clearly winning the day, at least in Germany and England. This is not to deny the traditional key role accorded to the Karlsruhe conference of 1860 and to its canonical hero, Stanislao Cannizzaro. But to a degree that has not previously been appreciated,[6] the revolution had already been largely consummated by the time of the conference, at least in Germany. The relatively invisible nature of these changes has led me to choose the name "quiet revolution." But however quiet it may have appeared to later observers, the participants themselves saw this period as revolutionary and looked to the 1850s as the critical decade. Evidence for this statement is provided in chapter 6.
Considerations such as these have convinced me that this quiet revolution was the last major transition leading to modern chemistry. One purpose for writing this book, then, is to highlight and chronicle this important period in more depth than has hitherto been attempted. A convenient vehicle for this purpose is the life and career of Hermann Kolbe (1818-1884).
Kolbe was one of the most outstanding and successful German chemists during the remarkable period in which German chemistry, like the wider manifestations of German industrial and political power, rose to a position of world leadership. A student of Friedrich Wöhler and Robert Bunsen, Kolbe succeeded Bunsen at Marburg in 1851. In the mid-1860s two major German universities, Leipzig and Bonn, had
vacancies, and Kolbe received a call (or offer) to each of them in succession; it was only after he declined the latter offer that Kekulé received and accepted the invitation to Bonn. Kolbe was Liebig's favorite chemist among the younger generation and was initially favored to succeed Liebig in Munich, although that offer never materialized. At the time of his transfer to Leipzig, no one in his generation except perhaps Hofmann could touch his reputation and standing in the field of chemistry.
Kolbe was a leading figure in two major interrelated inflection points in the history of science. One was the series of scientific events described above; the other was institutional and pedagogical in nature, namely, the phenomenal growth of academic laboratories starting in Germany after mid-century. Around mid-century, a laboratory accommodating 20 to 40 student workers at any one time was considered large and was qualitatively distinct from the eighteenth- and early nineteenth-century model of a small handful of elite students working with the professor on the basis of personal patronage. By contrast, Kolbe's lab in Leipzig (designed by Kolbe and dedicated in 1868) .was built to accommodate 130 student workers, and within a short time even this huge capacity was heavily oversubscribed. Among the first of what Jeffrey Johnson properly calls "second-generation institutes,"[7] it was for a decade by far the largest and most modern academic laboratory in the world and was much imitated. Its capacity exceeded that of Hofmann's well-publicized new institutes at Berlin and Bonn together .
Despite his preeminence, Kolbe has until now escaped any substantial biographical treatment in any language, and this fact in itself indicates a certain scholarly opportunity. But even more importantly, much can be learned about the rise of nineteenth-century German chemical science and industry from a careful study of Kolbe's career, in part because there are very few modern full-length biographies of German chemists of this period, and none at all in English. Despite a recent intensification of historical interest, the rise of German laboratory science and its societal implications are still very imperfectly understood, due largely to this dearth of detailed studies focusing on particular individuals and localities.
A prominent German economic historian has recently drawn attention to the need for studying the development of German industrialization from a regional perspective.[8] More generally, German historiography in this century has suffered from an overemphasis on the larger states, especially Prussia, which on occasion has created distortions and omissions. In a similar sense, it can be argued that the history of nineteenth-century German science has focused too much on events in Prussia, neglecting the smaller states before 1870.[9] This is particularly
ironic in the case of chemistry, as Prussia was among the most backward of the German states in this respect until Hofmann's call to Berlin in 1865; the leading personalities of the previous generation had been Liebig in Giessen (in the Grand Duchy of Hesse), Wöhler in Göttingen (in the Kingdom of Hanover), and Bunsen in Marburg (in Electoral Hesse) and Heidelberg (in the Grand Duchy of Baden). Following Kolbe's career as we do in this book provides a kind of grand tour of many of these smaller states: he was raised in Hanover, educated in Hanover and Electoral Hesse, employed for four years in the Duchy of Braunschweig, succeeded Bunsen in Marburg, then finally became Ordinarius in Leipzig in the Kingdom of Saxony. In each case, I am careful to establish some sense of the regional context of politics, culture, and Wissenschaftspolitik and to relate fiscal, administrative, and pedagogical details of the management of various German scientific institutes—including those of Kolbe's colleagues and rivals.
In conclusion, Kolbe's career provides an unexcelled lens through which to view transformations in pedagogy, theory construction, research practice, and administration of academic science in the context of German society. This is the case even though—or rather, precisely because —Kolbe did not think of himself as a "modern" (i.e., structural) chemist. Not far beneath the surface of a self-professed conservative and empiricist lay the activities of an imaginative and fruitful theorist, but a theorist with a curious twist. Kolbe had his own agenda and pursued it with single-minded intensity. He viewed himself as bearing the mantle of the great classical chemists, especially that of Berzelius. Although most of the collegial community regarded Kolbe as having helped establish the basis of structure theory, he attacked the structuralists so continuously and so viciously after 1870 that much of his posthumous notoriety—and, I believe, the dearth of serious biography—was due to his quirky obstreperousness. Within a decade, he succeeded in transforming himself from the leader of his field into an embarrassing and obnoxious crank. Kolbe's tragic fate was to have ended his life in opposition to most of what was then (and is today) regarded as the essential principles of organic chemistry.
As a consequence, by looking at the field through Kolbe's eyes we see the transformations of this period from the perspective of a man who was at once both an insider and an outsider. I have devoted much effort to understanding and motivating Kolbe's idiosyncratic viewpoint, but I have also striven to depict the wider context fully and fairly, not only in Germany, but also in France and Great Britain. It is only by such a combination of individual attention and contextual sweep that any biographical account becomes coherent and meaningful. Moreover, this kind of approach and the intriguing quirks of this particular
case study highlight a number of broader philosophical and historiographic issues, including generational change in scientific methodology, the nature of scientific controversies, the role of empirical evidence in theory assessment, and psychological and social factors in the contexts of discovery and justification. These issues are explored in the chapters that follow and in the concluding observations.
The natural audience for the story I have to tell consists of historians of chemistry and of nineteenth-century German science, but the novel aspects and historiographic richness of my case study give me the hope that the book will have more general interest for the history of science community. Accordingly, I have attempted to deal gently with the reader, assuming no particular knowledge of chemistry beyond simple definitions of atoms and molecules and a nodding acquaintance with the outlines of the science. The neophyte in chemistry will need to have recourse to the glossary, which covers some basic information and technical vocabulary regarding the modern (post-1860) theory of the structure of organic molecules.
Ever since the period described in this book, organic chemistry has had an intimidating reputation with laymen and students, and today it is often regarded as the principal distasteful hurdle to be overcome in a premedical curriculum. There is no question that organic chemistry in its full dimensions is a large and complex science, having important affiliations with other branches of chemistry as well as with physics and biology. However, the essential theory of the science for over a century—founded as it is on the principles of valence and structure and comprising compounds of a mere handful of chemical elements—is simple and clear. That structural basis, a kind of Tinkertoy-like set of schematic rules that can be taught literally in a few minutes, can carry a student (or a reader) remarkably far. Consequently, it is my hope and expectation that the following account will be widely accessible. I have tried to be equally kind to readers who may know little about the arcana of nineteenth-century German history. Thus, I hope that chemists with a taste for history will enjoy reliving these old battles and learning about the lives and social context of some of the figures whose eponymous reactions they teach daily to undergraduates.
I would like to conclude with a few personal comments. My first academic specialization was in organic chemistry, and I have never lost my fascination with this discipline and with its structuralist basis as characterized in the previous paragraph. I cannot help but feel that the great spurt in the growth, success, and standing of the field during the middle decades of the nineteenth century was to some degree a measure of the intellectual coherence and beauty, not to mention heuristic power, of structure theory as it was formulated and developed. There
is thus a certain irony in the circumstance that I have chosen as my protagonist the principal opponent of this lovely theory that I so much admire.
Moreover, I confess to having no admiration for the personality and character of Hermann Kolbe. Kolbe was capable of acting with generosity, selflessness, and love, and for most of his career he was a superb scientist, but many of his actions late in life displayed an array of prejudices and an intensity of malevolence that cannot easily be excused. Such feelings of a biographer carry a certain advantage, in that one is thereby inoculated against the danger of hagiography that is so endemic to the biographical genre. The corresponding issue on the other side is that one must be scrupulously fair, and I hope my readers will judge that I have been.
Without wishing to draw an exact parallel, I find myself in a position similar to that of the Stalin biographer Robert Tucker, who detests his protagonist, and depicts him as a neurotic personality without any consciousness of his own wickedness. To my mind, Kolbe also appears to have developed a mental illness. Not being a psychologist, I have come to no conclusions on the exact nature and etiology of Kolbe's neurosis or personality disorder, if such it was. I have, however, attempted to provide empirical grist for whomever might wish to turn the psycho-historical mill, by investigating Kolbe's upbringing, physical health, family life, relationships with students and colleagues, use of language and metaphor, and stresses and strains of daily life. As with Tucker's Stalin, it is clear to me that Kolbe's internal motivations and self-justifications, although twisted, were absolutely pure. Finally, like Tucker, I conclude by noting that my motivation for choosing this particular subject was simply that here was a fine historical opportunity: "when you seek to penetrate the heart of darkness, it is very important that the project be interesting from the scholarly point of view."[10] And whatever else one might say on the topic, Kolbe is a fascinating subject.