Legacy from a Chemistry Teacher
William Cullen was a chemistry teacher of whom one of his students once said, "Chemistry, formerly little studied here, has been by him new modelled, and raised to the highest reputation; so that here there are now more students engaged annually in this pursuit than in any other except anatomy." This was in 1766, and Cullen was Professor of Medicine and Chemistry a t the University of Edinburgh. The "new-modelled" chemistry was new indeed. Cullen's chemical doctrines, the force of his arguments and the power of his example influenced chemistry, natural philosophy, and scholarly thought throughout the English-speaking world. They resulted in Joseph Black's discovery of latent heat, and this-according to some-led directly to Lavoisier's chemical revolution. They inspired philosophic debate, progress in medicine and pharmacology, and inventiveness in industrial chemistry. They firmly estahlished chemistry as a separate and unique scientific discipline in Scottish universities. The basis for Cullen's appeal as a teacher and his influence on the thought and activity of scholars and practitioners alike rested in part on his breadth of conception and clarity of purpose, and in part on his view of chemistry as a separate and specialized discipline. An eloquent and humane teacher, endowed with a deep sense of intellectual integrity, Cullen lectured in a style that "sparkled with a vitalizing purposiveness that looked beyond the confines of the specific subjects he taught." At the same time, he was a specialist. He knew that the phenomena chemistry sought to explain-acidity, alkalinity, inflammability and metallicity-were of a different order of complexity than those being studied by the natural philosophers. He believed that chemists were responsihle for creating theories to account for their own phenomena-the.ories that might start by explaining things in terms of the elective attraction between particles and the amount of heat or fire contained in bodies. Despite his commitment to specialization, Cullen maintained active interaction with colleagues in philosophy and medicine. David Hume and Adam Smith were his friends; John Locke influenced him so strongly that Cullen recommended that his students study Locke's doctrines of understanding in preparation for his lectures on chemistry. [For excellent intellectual biographies of William Cullen and his student, Joseph Black-with whom many early American chemical educators studied-see: A. L. Donovan, "Philosophical Chemistry in the Scottish Enlightenment", Edinburgh University Press, Edinburgh, 19751. Much in science, philosophy, and medicine have changed since Cullen made his chemistry courses a living center of learning a t Edinburgh in the 18th century. Yet, many of the attitudes, ideas, instincts, and perceptions that guided him in his role as professor and chemist have meaning for us two centuries later. Among these is the perception of chemical science as an experiment-focused institution having philosophic, theoretical, and utilitarian interests and obligations. Its philosophic interests are seen as centered around its use of the power of thought to seek the truth and to pursue the common good. Its theoretical interests reflect the desire to understand the behavior of substances, the causes of natural phenomena, and the nature of the world itself. Its utilitarian interests recognize the essential role it can play in health, medicine, agriculture, industry, mining, and other practical arts. Together, these interests and obligations fashion the very character of
chemistry; from their synthesis comes its moral fiber; adherence to them establishes its legitimacy and authority. . necmd notion that ~ u i d e d(.'~tlle~;il!~d thnr has rmuniny today was his idenrtfi( atigjn c l i 111smissigm: 11, urtimlate and advance the best of modern chemistry, and to make it a living center within the university. At least three important ideas are imolicit in this statement. The first is that chemistrv. .. like all sciences, is an on-going, constantly changing and continuouslv renewinn- activitv. Unlike the arts and humanities. it is always moving away from its past. A second implication is that conflicting views within chemistry are essential and inevitable, and that they lead to changes in its fundamental beliefs and values. To acknowledge a person as a competent chemist admits the possibility that he was, or is, in many ways mistaken. A third implication is that the teachers of chemistry-those who tell its story and interpret its meaning for the uninitiated-must develop and exercise the skills needed to identifv what is best in modern chemistrv, and~-what is~~~-~ still valid in traditionalchemistry. T o d o this, they must maintain communication with all uroeressine areas of the science. In addition, those chemists whtrmake important advances have an obligation to explain both the nature and the known important implications of these advances to those who teach. To articulate and advance the best of modern chemistry, one must become attuned to its ever-changing scene and involved in its ever-stimulating controversies. Only in this way can its true story be told. William Cullen's instincts told him what too many teachers, scientists, and other professionals seem to avoid today; namely, that in all our work we must reckon with things of the spirit. As Cullen sensed. and as the record of advances in r~aI chemistry since his rime clearly rhous, i ~ ~ t r l l , ~ r ~,nssit,n, d m nmtrilnltean indisot.t~iiillcelement lc,scitmcr. \Ve thtnk of Marie Curie performing the labors of Hercules in separating the radioactive fraction from the tons of pitchblende: of Biot. who wept when Pasteur showed him thebptically active separation from racemate; of Kekul6 and his dreams, and of Kolhe's ridiculing van't Hoff's theory of asymmetric carbon. Although there alwavs is dancer that emotion can overchol&ical protection affoided by dktachmini and specia"ization have led to so manv researchers becoming . homed ... down in m~.ticulous.posirivisrir, ~aclunlinvest~gntionidlowed hy unthinking interprrration 01 the d a n and facts t h n ~it mechanistic, computer-minded conception of things has cast a pall over too much scientific work. Perhaps our most creative periods were those in which scientists-were passionate ahbut their beliefs and commitments while keeping reason, objectivity, and emotion in balance. A precious int&ectual passion appears to he the stimulus for good chemistry and good science. Used properly, it brings out the best in our ability to reason, to learn and to be creative. Cullen experienced many h a m v davs as a chemistrv teacher. ~ l t h o u he ~ hcontributed6niy one publication to thk chemical literature of his age, he not only trained new thinkers and new researchers who were to follow him and to make significant contributions to chemistry, he also prepared an . . audtence whu cuuld apprectatr u,hat these !~eu,chemists were doing. All this must have giwn him some snr~shrtion. W'H, Volume 56, Number 3, March 1979 I 139
