David M. Knight Department o f Philosophy University of Durham Durham, England
II
Teaching the History of Chemistry to Nonchemists
I t is not merely from the grand perfection of science, hut even from every progression of it, that we may look for advantages-for some more noble views of the external universe, for some spplicstians of the powers of things, for the solution of the enigmas of the natural world. In these respects chemistry is the most fertile of all the sciences; and the one, even in those ages when it was least pursued, which produced thegreatest benefits for mankind;-the soil hearing the richest harvests, even when uncultivated (1).
Particular circumstances a t Durham University mean thatvery few chemists take courses on the history of science. Indeed, a considerable proportion of those taking such courses have had no formal training in physical sciences; and furthermore, scientists can only study the history of science in conjunction with the philosophy of science. This means that the history of chemistry has to be taught as a branch of the history of science rather than as a subject in its own right. Whereas it should be clear to the chemists that the development of chemical atomic theory, the Periodic Table, or valence theory are important, though he may refuse to find them interesting, for the nonchemists even their importance is not apparent. Again, it is difficult enough for the chemist to put himself in the position of the experimentalists of long ago; for the nonchemists, the due appreciation of laboratory work is almost impossible (8). The historian of chemistry must be careful not to get bogged down in teaching a smattering of modern chemistry in order to get around these diiculties; instead, he should boldly grasp the nettle and set out to teach his subject as a branch of general intellectual history and in its relation to other aspects of history. A virtue can be made of this necessity; for the perspectives thus attained should be new even to those who have some acquaintance with modern chemistry, and broad features of the development of the science should become apparent in an approach in which much detail has perforce been omitted. Another advantage is that the history of chemistry is no longer seen as a single main line of advance, with regrettable detours like that through the phlogiston theory. Past controversies must be seen as involving choice between live options; theories must be judged according to the information available, and the canons agreed upon, a t the time they were proposed. For nonchemists, studies of the relationship of chemistry to other sciences can provide evidence on how science works by analogy-and how different analogies seem persuasive to different people in different countries and a t different times. For chemists they can indicate the value of knowing more than just chemistry; for concepts are sometimes taken up from the history of chemistry and sometimes from other sciences. The
apostle of normal humdrum science, C. P. Snow, believes ($) that "no nuclear scientist today would study Rutherford's researches of fifty years ago. Their substance has all been infused into the common agreement, the textbooks, the contemporary papers, the living present," and that by 2070 "any decent eighteen-yearold student of physics in that year will know more physics than Newton." If this were true, it would seem to make the sciences inhuman disciplines, incapable of engaging man's primary interests; and the study of their history would revert to antiquated scientists of hagiorgraphical tendencies. To teach the history of chemistry to anybody, let alone nonchemists, would be to risk circulating obsolete information and at best would provide anecdotal light relief to the antiquarian-minded. Luckily for those teaching the history of chemistry, prominent chemists in the past have often looked further than this, and in our day the chemist Llichael Polanyi reminds us that no knowledge is impersonal; and nonchemists have sought in the science data for a cosmology. The emergence of professional chemists has been the subject of sociological investigation; the impact of chemistry on social history can be followed by studying the development of chemical industry or of laws on pure food and drugs. Chemistry is and was concerned in such fields as the preparation of dyes and pigments, the conservation of works of art, and the techniques of lithography and photography. It would be curious indeed if a science connected with so many aspects of history had no serious history of its own, apart from a few contingent facts about discoveries (4). But it is with the cosmological and metaphysical aspects of chemistry around 1800 that we shall now concern ourselves. There are two questions which arise here: "How are the facts of chemistry to be expressed"? and "What does chemistry tell us about the world? Can it cast light on the existence of God, freedom, and immortality"? The two questions shade into one another; it would be a mistake to suppose that all chemists a t this time concerned themselves seriously with either, but there are enough sources to make it possible to get this interest across in teaching. The order supposedly evident in the biological and physical spheres has been long used to demonstrate the existence and benevolence of God; and from the later seventeenth century until the middle of the nineteenth century, prominent scientists and divines, orthodox and heterodox, composed treatises of this sort. Joseph Priestley made this more specifically chemical in arguing for atoms as point centers of force rather than hard spheres. Matter thus became active instead of passive and brutish, and spirit became redundant. The PlaVolume
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tonic doctrine of the immortality of the soul was therefore exploded; t,here could not be immaterial souls. Another Platonic corruption, the doctrine of the Trinity, could also go, and Priestley advocated a Unitarian materialism, and the resurrection of the body. Much discussion in succeeding generations revolved about the relationship between chemistry and materialism. Lavoisier's chemistry was materialistic in that properties such as acidity, and also t.he various states of matter, mere accounted for in terms of the presence or absence of material substances; in these cases, oxygen and caloric. The atomic theory, both before and after Dalton, was despite the efforts of Boyle the chemist and Cudworth the t,heologian often identified with materialism. Davy's work is important in this connection bccause he att,acked the material theory of heat,; and in his studies of t,he oxides of nitrogen and of diamond showed that the properties of things do not simply depend upon their constituents. The various oxides of nitrogen-and air was supposed to be one-possessed very different properties and yet had the same constituents, in different proport.ions; and charcoal and diamond were chemically identical. Davy also, in establishing the elementary nature of chlorine, showed that acidity did not depend upon a material principle nor did combustion require one. All this, and his demonstration that elect,ricity and chemical affinity were manifestations of one power, seemed to confirm the view of German Romantics such as Ritter and Schelling that chcn~icalcombination involved more than juxtaposition of particles, and that nature should be seen as active; t.hus me find Davy's friend Coleridge writing of the charm of chemistry, and of "the almost universal interest excited by its discoveries" because it represents, in its "striving after unity of principle through all the diversity of forms," "poetry, as it were, substantiat,ed and realized in nature." In this Heracleitian chemistry, things only endure as columns of smoke or waterfalls do. Hegel went so far as to urge chemists to concentrate upon the chemical process, and not bother much about the starting materials or caput mortuum; and Oersted considered the transition to a dynamical chemistry to be more radical and important than the change from the phlogiston theory to the equally materialistic views of Lavoisier (6). All this may sound curious but hard to teach; but in fact sources are available though they are harder to understand than mainstream chemistry; and some willing suspension of disbelief on the part of the student may be necessary. This is likely to be easier for the nonchemist, who is not blinkered by hindsight and can thus share these perspect,ives without asking too much how closely they resemble those of living chemists. But the imponderables, heat, light, electricity, and magnetism, which in the first decades of the century seemed to occupy a position between material and immaterial substance, soou became forms of energy, losing some of their philosophical and theological interest. It is perhaps better to turn to such popularizations as Mrs. Marcet's "Conversations on Chemistry," Liebig's "Familiar Letters," and Johnston's "Chemistry of Common Life," though there are no modern editions of them. They present in a more palatable and discursive form what can be found in the textbooks of the 286 / Journal of Chemical Education
period. Also useful are such sources as chemists' Presidential Addresses to the British Association and lectures at the Royal Institution; and accounts of chemical writings in the Edinburgh Quarterly,and other reviews which played a very important part in nineteenth centuly life and kept laymen aware of scientific advance. Encyclopedias can also be used with advantage; Rees' Cyclopedia was particularly strong on technology; the "Encyclopedia Britannica" had Thomas Thomson associated with it in its early editions, and is correspondingly strong on chemistry; and the Encyclopedia Metropolitans tried to set out the sciences in a logical rather than alpliabetical order, and had booklength articles describing them. Naturally articles in encyclopedias tend to be factual rather than speculative in emphasis, and some are dull; but for showing what was accepted knowledge at a period they are very useful, and more condensed than textbooks. To concentrate thus upon chemistry in its external relations is not to imply that external factors had more influence than internal ones. It would clearly be perverse to argue that Schelling, Hegel, Coleridge, or Whewell had more impact on the progress of chemistry than Lavoisier or Berzelius, and us a general principle external factors should not be invoked until internal ones have been exhausted. All that is implied here is that those facets of chemistry which have in the past interested laymen are likely to interest nonchemists studying the history of chemistry. On the other hand, the canons of chemistry have been affected by philosophical and other doctrines current at the time; and prominent chemists, even if they have not been guided in the laboratory by metaphysical or theological beliefs, have like Newton at least welcomed their discoveries being used to support such beliefs. Neither an internal nor an external history of chemistry can be complete; since in a course of finite length one cannot teach everything, it is better to concentrate on whatever is going to mean most to teacher and students. For nonchemists, to use case studies from chemistry to illustrate general questions in philosophy of science, and to find what general points contemporaries emphasized in chemistry, seems as promising an approach as any.
Literature Cited Dnvr, H.. "The Collected Worke" (Edilov: DAYY, JOHN), Smith Elder London, vol. V I I I , p. 326, 1842. (2) P*n*n*r, M.. "Chemical Manipulation." reprint with introduction by D. M. Knight. Frank Cess, London, in press. is a useful guide to
(1)
techniques. C. P., T. S.,
(3) SNOV, The Timm Lde7ar.y Supplemenl, p. 739 (July 9, (1970): see Kunn. "The Struoture of Scientific Revolutions," Chicago
L.,
U. P., Chioago. 111.. 1962; SCOTT,V. "The Conflict between Atomism hnd Conservation Theory," Elsevier, NBIVYork. (4) P o ~ m r r M., , "Personal Knorvledge." Routledge & Kegan Paul. London, 1958: HOLT,l3 W. G., J. 31, 181 (1970): IHDE, A.. "The Develaoment of Modern Haroer and Row
Bra.
Sociol., Chemistrv."
1970.
