42 ll. t. Ch. (8

. S. C. rn, Ed., Clltd Wr f Cnt frd, l. 4, lnprvrd r, Cbrd, MA, 0, p. 82. 4. . rtl, h trn f hltn Etblhd, hl dlph, 800. . . . rtntn, A tr f Chtr, l. , Mlln, ndn, 62, p. 0. 6. . . Cndt, Ann. Ch., 8, 2, 88. . Mr. l, rh übr d Wdrhrtlln dr Mt ll drh Wrtff, hphr, Shfl, Shfllbr, hflt Wrtff, phphrt Wrtff, Göttn n, 8. rnltd b A. G. W. ntn. 8. . W. Mllr, "tr f th Wtr rbl (Mr. lh hr f Ctl", . h. Ch., 1903, 6. . Mr. lh, An E n Cbtn, phr, hl dlph, 80. 0. . A. vnprt, "n nd lvn, th 8 tr f rfr h Cpr", . Ch. Ed., 1976, , 4. . . A. vnprt, "h Chtr tr f th rnd, Inn, Sntf nd lntd Mdp: rfr h C h hé Mthll pr, nn Cll, 88", hn nd Mr rnl, , , 28. that "there must be more historians of the American Civil War 2. . Cpr, A pl t Mr. r Invtv nt Mr. than there were generals fighting it and, of the two groups, the Cpr nd Mr. Wtt n th f Cn" , hnn, ndn, historians are the more belligerent"(2). nd lnr, Mnhtr, 2, pp. 8. It has been said that the art of revolution is really the art of . . Mln, h bl f f h Cpr, 88, making explicit the implicit and, on my better days, I delude Sth Crln, Clb, 6. myself that this simple aphorism is able to account for both the elements of continuity and discontinuity present in all such conceptual upheavals. If this characterization is even approxi- Dr. Derek A. Davenport is Professor of Chemistry at Purdue mately acceptable, then there is one very fundamental aspect University, West Lafayette, IN 47907, where he teaches a of the older chemistry which Lavoisier's work failed to trans- course on the history of chemistry. Kathleen M. Ireland is form immediately and that is the question of how to theoreti- currently completing an M.S. in Chemical Education at Pur- cally rationalize the specific or intrinsic properties of matter. due and plans to teach high school after graduating. For though, as I will argue later, Lavoisier implicitly provided the techniques which would lead to the modern viewpoint, he did not himself explicitly confront this issue, let alone revolu- tionize it. THOMAS DUCHE MITCHELL AND THE As even a superficial glance at 19th century chemistry CHEMISTRY OF PRINCIPLES textbooks (and some of the better 20th century textbooks) will show, this problem lies at the very core of chemistry's identity William B. Jensen, University of Clncinnati as an independent science (3). Whereas classical physics deals with the general properties common to all matter, such as mass, That Lavoisier' s work constitutes, in some fundamental sense, inertia, the laws of motion, etc., it is chemistry which deals with a true chemical revolution has never been doubted by chemists, the individuality of different kinds of matter; with their specific whether his contemporaries or those later generations blessed properties; with why they possess the colors, textures, odors, with the gift of historical, albeit whiggish, hindsight. Histori- and flavors they have; and with why they can be interconverted ans of science, on the other hand, have been less certain and a into certain kinds of materials with equally mysterious arrays small, but vocal, literature has evolved debating the exact of specific properties, but not into others. revolutionary content of Lavoisier's work, whether it was The modern interpretation of this problem is based on the indeed a true revolution, and even the question of whether atomic-molecular theory and the hypothesis that these proper- scientific revolutions exist in the first place (1). At times, and ties are in some manner the emergent result of the number, with more than a little exaggeration, one is tempted to compare kind, and arrangement of a substance's component atoms or, in th is state of perpetual historical uncertainty with David Donald's more reductionist terms, of its ultimate electronic composition evaluation of the state of American Civil War history - namely and structure. But from the time of the Greeks until the end of ll. t. Ch. (8 4 the 18th century, the accepted rationale was quite different and both material and isolable, though it might be argued that this was based instead on the concept of property-bearing prin- materialization was the end result of the increasing tendency of ciples or elements - the idea that the most important or salient later variants of the phlogiston theory to identify phlogiston characteristics of a substance were in some fashion the additive with hydrogen. Likewise, unlike the older principles, which reflection of the properties of its components (rnuch as a were literally the personification of the properties which they reddish color in a paint mixture automatically implies the conferred on material substances, hydrogen, oxygen and nitro- presence of a red pigment). Instead of being discontinuous and gen possess none of the properties of water, acidity or alkalin- emergent, specific properties were thought to be continuous ity which they supposedly imparted to their compounds. In and variable like those of physical mixtures (to make the paint passing, it should be noted that Robert Siegfried has also redder one simply adds more red pigment). Though the iden- recently challenged Perrin's interpretation, arguing instead tification of both the most important properties and their that this class of five elements is really a collection of odds and material approximations would vary from the earth, air, water, ends which Lavoisier was unable to group using his theory of and fire of the Greeks, through the sulfur, salt, and mercury of salt formation, which forms the basis for classifying the other the iatrochemist, to the various hybrid four and five element elements in the table - in short, that it is a kind of taxonomic theories of the 17th century, and finally to the phlogiston of the miscellany (7). 18th century, the underlying assumptions remained the same. Whatever the final consensus on this larger issue, there is Indeed, this concept was analyzed in some detail by David no doubt that Lavoisier did use oxygen as a generic property- Oldroyd in 1970, who found that it had an almost bewildering bearing principle and, if he failed explicitly to challenge the array of philosophical precedents, the most important of which basic assumptions of the theory of principles, who did and at was the Neoplatonic concept of ideal forms - the view that there what point did chemists switch to the modern view? Alas, with existed ideal essences corresponding to each of the character- the single exception which I will discuss in a moment, 19th istic properties which, though nonisolable, were transferable century chemists - at least as far as I can tell - never did from substance to substance and of which the isolable material explicitly challenge this concept and, for that matter, never analogs of earth, air, sulfur, etc. were but imperfect reflections explicitly recognized that there was a fundamental difference (4). between their premises and those of Lavoisier and his prede- The point of this rather lengthy philosophical digression is, cessors. Rather the change to the modern view seems to have of course, that not only did Lavoisier fail to affect an explicit occurred so slowly, or perhaps I should say, so obscurely, as to revolution in this time-honored mode of explanation, he ac- tively carried it over into his new chemistry, albeit in a slightly modified form, and, in actual fact, it died a slow and very obscure death in the early decades of the 19th century. The simplest evidence for this contention is Lavoisier's well-known use of oxygen as a principle of acidity. However, an even more pervasive argument was made by Carleton Perrin in 1973 as a result of analyzing the table of simple substances which appeared in Lavoisier's 1789 Traité (5). As Perrin noted, the first five entries in the table: light, caloric, oxygen, nitrogen (azote) and hydrogen are singled out and, in contrast to the other entries, which are always referred to as "simple substances", are alone in being given the name of "elements" - or to be more specific, are labelled as "simple substances belonging to all the kingdoms of nature, which may be consid- ered the elements of bodies"(6). Since caloric is further described as being the principle of heat and Lavoisier consid- ered oxygen to be the principle of acidity, nitrogen as a possible principle of alkalinity, and hydrogen as the principle of water, Perrin contended that the use of the word element in this context was intended in its older property-bearing sense and was a residual reflection of the older theory of property- bearing principles. There are, however, some problems with this interpreta- tion. In contrast to the older principles, which were both non- tl p f th nl pblhd vl f th Mr f th Cl material and nonisolable, oxygen, nitrogen and hydrogen are bn Chl St n hh Mthll ntl pprd. 44 ll. t. Ch. 5 (8 have been almost undetectable. Indeed, if we are to believe And n th frt pl, I ld brv, tht hl th dtrn f n Oldroyd, historians of science have not done much better than nflbl prnpl ppr t nrrt, t l the chemists with this subject, as he claimed in his 1970 article nphlphl. And hl I th, I lln t dt th that they did not gain an explicit recognition and appreciation rrr ftn d n th f th tr, prnpl f dt. th of the historical importance of the chemistry of principles until l r prpr. It ld b jt phlphl, hn pn the 1960's. f ntrl lt, t rt tht th d ntttd th prnpl f The sole exception to this litany of ignorance is an obscure ntrlt tht t rdd, xlvl, n th ll. brd 19th century American chemist by the name of Thomas Duché d th ppr Shll thn b xd, hn tht h Mitchell and, given the importance of this issue, as just out- bd btbl, f rt tht th prnpl f nflblt lined, in defining both the nature of Lavoisier's revolution and bln t n nt r, pn f n d, hll b lld t the course of its post-revolutionary consolidation, the rele- ll n f t nttnt th dfn prnpl? ... t n b f vance of briefly discussing Mitchell's critique of this concept, tr, ppltn f rd, t tht th r tht th prnpl as well as its suitability as a concluding footnote to this f nflblt r f dt. Infltn nd dt r fft symposium, are both self-evident. rltn fr th tn f rltv nd r nt ttrbtbl t Mitchell was born in in 1791 and studied nl nt r prnpl. medicine at the University of , receiving his M.D. degree in 1812 (8). While still a student, he was drawn into the In other words, Mitchell is contending that chemical and activities of the Philadelphia chemical-medical community, physical properties are not the inherent qualities of isolated having spent a year in the drug store and chemical laboratory substances, as implied by the chemistry of principles, but of Dr. Adam Seybert, a prominent member of the community rather the relative, system-dependent result of the interaction who specialized in the chemical analysis of minerals, and his of several substances, one of which could correspond to the apprenticeship under Dr. Joseph Parrish, who had been active organs of sensation in the human being. Thus, in another essay, as a chemical lecturer in the Philadelphia area. Mitchell began Mitchell wrote (12): to publish articles on chemistry and medicine while still a student, his first known chemical contribution, "On Nitric and Whr phlph nd rn hn nflblt, r th pr Nitrous Acids", appearing in the Mdl M in 1809. f brnn, nnd t n ltr nt? I hlln th hl This was followed two years later by his organization of a ht f ppnnt t th ntphlt t t dd n nl student chemical society in collaboration with a fellow medi- ntn n ll ntr n hh n bd prtl p n cal student named George Lehman. Known as the Columbian blt prnpl r lt. Whn p f th prprt f Chemical Society, it was the third such society organized in the bd, tt, ll, t., d nt n tht n f th p Philadelphia area (9). The first, which had been organized in p tv lt. h r rl ntn r fft rltn fr 1789 by John Pennington, had lasted only a year, whereas the th tn f th bd n r rn f tt, ll, t. Infl second - The Chemical Society of Philadelphia, organized by tn, l dr, th rlt f rltv rtn nd nt th Coxe in 1792 - had lasted for about 15 years (10). prdt f nl nt. Though the Columbian Chemical Society would last for only three years (1811 - 1814), it was unique in that it succeeded, Though other chemists would criticize Lavoisier's theory unlike its two predecessors, in actually publishing a volume of of acidity on purely chemical grounds, that is, in terms of memoirs in 1813. whether or not all acids really did contain oxygen, it is This 221-page volume contained 26 papers by members of important to realize that Mitchell is attacking on general the Society, nine of which were written by Mitchell, who had, philosophical grounds the premises behind the use of prin- incidentally, also served as the Society's first president in ciples in general, be they of acidity or inflammability. And he 1811. It is in these papers that Mitchell's initial critique of the is doing so on the basis of a critique of how we perceive and chemistry of principles first appeared, largely in connection detect the properties of matter in general - namely, that all with his defense of Lavoisier's system against Davy's work on properties are due to purely relative effects in which all of the the elemental nature of chlorine and against a revival of the interacting agents play an equal role, for (13): phlogiston theory proposed by John Redman Coxe, who was at the time Professor of Chemistry at the University of Penn- ... ht ntrl lt, bt th rlt f th tl ntrtn f n sylvania. d nd ll, nd ht btn, bt th fft f th tl Attacking Coxe's identification of hydrogen as a principle prtn f xn , n hp r thr, nd btbl? of inflammability on general philosophical grounds, Mitchell readily admitted that his objections applied with equal force to It is interesting to note that Mitchell's critique is virtually Lavoisier's use of oxygen as a principle of acidity. Mitchell identical to that given a century later by the German philoso- wrote (11): pher, Ernst Cassirer, who, in discussing the physics of Anaxogo- ll. t. Ch. (8 4 ras and Aristotle, referred to their "hypostatization of sensuous qualities" or the "procedure of converting the relative proper- ties of sensations into the absolute properties of things" (31). In 1831 Mitchell, after practicing medicine for nine years in Frankford, Pennsylvania, just outside of Philadelphia, moved to Cincinnati to accept the position of Professor of Chemistry and Pharmacy at the Medical College of Ohio. The next year he published a 553-page textbook based on his lectures at the College, entitled Elements of Chemical Philosophy, in which he again reiterated his relativist position on the origins and nature of specific properties in chemistry (14):

On th bjt f n dfn prnpl, I hv vn v t lnth, r . It nt b , hvr, t tt, n th pl, tht th dvn hh hl n ntntl n, hv nfrd rl pnn n th pnt. I rpt, tht th tr dfn prnpl ttrl nphlphl, nt nl ppld t xn, bt t hdrn, nd t vr nt hh b ppd t xrt n nfln n dvlpn d prprt. Evr rlt n ntr r prdd b rt, rltv fft, nd vr t n rnd, rtl r drtl, n th plhnt f th nd, ntl t tht nd. n, I nt, tht f n d b dvrd, hh hll ntn 0 pnnt prt, ll hh r rt n th frtn f th pnd, th nl hrtrt f hh dt, I ffr th l prprt f n n, f th thr, f t nttnt, tht th r tht th dfn prnpl. Abtrt fr th pnd thr f t prt, nd dtr th plr, dtntv hrtr f th d.

B y way of biographical completeness, Mitchell left Cincin- nati in 1837 to become Professor of Chemistry at the Medical School of Transylvania University in Lexington, Kentucky. In tl p f Mthll txtb n hh h rtrtd h 1839 he gave up teaching chemistry, concentrating instead on rt f th htr f prnpl. therapeutics and materia medica. After serving as Dean of the Transylvania Medical School for several years, Mitchell re- ous release and combustion of phlogiston (now identified as turned to Philadelphia, where he died in 1865 at the age of 74. hydrogen) from the inflammable, the hydrogen having im- Was Mitchell justified in his critique of the concept of parted the property of inflammability to the combustible in the property-bearing principles or was he merely an isolated first place. In addition, Franklin Bache, a fellow member of the American amateur flogging an already long-dead horse? In Columbian Chemical Society, actually published a paper in the terms of his immediate environment, at least, the answer is that Society's memoirs entitled, "An Enquiry into What Circum- the attitudes of many of Mitchell's fellow chemists did indeed stances Will Warrant Us Justly to Reckon Any Substance a justify such a critique in 1813. As already mentioned, most of Principle of a Common Property of Any Set of Bodies", in Mitchell's original comments appeared in his analysis of John hh he attempted to outline criteria for the development of Redman Coxe's recently published theory of combustion, a consistent chemistry of principles, albeit all now thoroughly

which made controversial use of Humph!) , Davy's apparent materialized (16). discovery of hydrogen in such combustibles as sulfur, phos- All of these cases indicate that not only chemists of phorus and carbon, to support what was, in essence, a revival Lavoisier's generation, such as Samuel L. Mitchill, but those of a form of the phlogiston theory similar to the late 18th of the next generation as well, such as Coxe and Bache, though century variants proposed by the French chemists, Macquer apparently accepting the results of Lavoisier's system, contin- and Guyton de Mourveau, and by the American chemist- ued to regress into explanations and modes of thought based on physician, Samuel L. Mitchill (15). Essentially, the theory the concept of property-bearing principles - in short, that suggested that combustion involved not only the combination Lavoisier's work did not explicitly revolutionize this concept of the inflammable substance with, oxygen, but the simultane- and that it lingered on well into the first decades of the 19th 46 ll. t. Ch. 5 (8

century (17). hd f lr, r tt, lblt r vltlt ntrdt btn, Even as late as 1832, Mitchell still had some justification nd n rt pd f, th prprt hh r for his remarks in his textbook. In 1828, just three years before ndrd n thr prnpl. h n lln r rrr hh Mitchell came to Cincinnati, Elijah Slack, his predecessor as drn htr hhl ntrtd t vrthr (tl ddd. Professor of Chemistry at the Medical College of Ohio, had published a small pamphlet on chemical nomenclature for the Likewise, the Scottish chemist, John Murray, gave a detailed students at the college (18-19). This was the last of a long line discussion of the same law in his 1806 text, a volume also easily of short chemical nomenclatures published in the United accessible to Mitchell, and even cited quantitative data on States, the first being Samuel L. Mitchill' nltr f th densities to demonstrate its truth (25). Though the acceptance Chtr, which appeared in 1794 (20). In this pamphlet, of this law is tantamount to rejecting the concept of property- Slack continued to adopt an organization similar to that used by bearing principles, it is interesting to note that neither Fourcroy Lavoisier in his rté, the sole difference being that the class nor Murray carried through with it in the later descriptive of acidifying principles or supporters of combustion had now sections of their books, where both continued to employ been generalized, via the suggestions of Davy, Gay-Lussac, Lavoisier's acidity principle, and it is only Mitchell, as far as Thomson and others, to include not only oxygen, but other I know, who explicitly spelled out its logical consequences for highly electronegative elements, such as the halogens and Lavoisier's original system. sulfur. Thus one had not only an oxygen family of acids, bases While the apparently unique approach of Mitchell to this and salts, but a chlorine family, a sulfur family, etc. (21). problem certainly merits the attention of historians, we are still Finally, we need to ask the question of where Mitchell got left with our original question of when and why the 19th his ideas on the origins of specific properties. Given his em- century chemist abandoned the chemistry of principles, for one phasis on the emergent, relativistic nature of these properties cannot seriously maintain that Mitchell had a major impact on and their interaction with our organs of sensation, the most his fellow chemists. Though he published, in addition to obvious source which suggests itself is the writings of the 17th several textbooks, more than 20 papers on chemical subjects, century British philosopher, John Locke, and his famous virtually all of them appeared in obscure medical journals with distinction between primary and secondary qualities (22). limited circulations which, like the Mr f th Clbn Unfortunately, we do not know enough about the details of Chl St, became defunct after only one or two Mitchell's education to show an explicit influence. In addition, volumes. Likewise, his impact as a teacher of chemistry and as the recent book by Peter Alexander has shown, most of as a textbook author was limited to audiences of beginning Locke's ideas on this subject are in reality a popularization of medical students in the newly-founded medical schools of concepts found in the writings of Robert Boyle and are a logical Ohio and Kentucky, which failed to produce any future genera- consequence of accepting a mechanical atomic theory of tions of chemists to carry on his particular point of view. matter - which Mitchell most certainly did (23). A tentative answer to our question can be obtained, how- Actually, there are some precedents in the chemical litera- ever, by briefly considering why the proposition that: ture of the period which are more likely candidates and which Mitchell would have almost certainly encountered in the properties f (composition) (1) course of his chemical training. The most important of these is found in the multi-volume text, A Gnrl St f Ch was so important to the 18th century chemist. Read from right l Knld, written by Lavoisier's friend and collaborator, to left, this statement can be charitably interpreted as one of the Antoine Fourcroy, which had been translated into English by theoretical underpinnings of alchemy. However, long after William Nicholson in 1804. In the first volume of this work, chemists had ceased to seriously pursue the dreams of the Fourcroy offered a list of established laws governing chemical alchemist, this proposition continued to be of importance as change, the sixth of which reads (24): read from left to right. For virtually the only way 17th and 18th century chemists could operationally implement the claim that Cpnd frd b hl ttrtn, p n prprt chemistry was the study of the composition of materials was dffrnt fr th f thr pnnt prt. via the premise that the composition of a substance could be directly inferred from its properties. Thus the presence of a In commenting on this law, Fourcroy further noted that: sharp taste automatically implied the presence of "salt", in- solubility and refractory behavior the presence of "earth", ... ht hv ln blvd th ntrr t pl ... h volatility the presence of "air" or "mercury", inflammability thht, n ft, tht th pnd pd prprt ntrd the presence of "sulfur", etc. t btn th f thr pnnt prt tht t bd, vr By changing the meaning of the word "composition" in lrd, vr pd r npd, lbl r nlbl, fbl r relation 1 from "nonmaterial, nonisolable principles" to nfbl, fxd r vltl, d, n hl bntn, "material, isolable simple substances", and by supplying, via ll. t. Ch. (8 4 the law of conservation of mass, a tool which allowed chemists synthesize from an unknown substance one or more known to accurately distinguish between decomposition reactions, on compounds, from whose established composition one can the one hand, and addition and displacement reactions, on the infer the composition of the unknown (thus, in classical or- other, Lavoisier supplied the means to circumvent this relation. ganic analysis, the unknown is converted into carbon dioxide Composition could now be inferred, not from properties, but and water) - a point which was emphasized by Fourcroy as via the use of chernical reactions to separate and isolate a early as 1804 (28). Even the known compounds produced in species' material components. As the century progressed, the the analysis may never have been directly decomposed into essence of a substance's identity came to be viewed less and their elements, but rather have, in turn, compositions inferred less in terms of such properties as inflammabilty, metal hefty or in a similar manner via their interconversions into yet other acidity and more and more in terms of mapping its position in known compounds - the final end set of compounds actually the reactivity matrix - that is, in terms of what it could be made having been directly decomposed into their elements being from and what it could be converted into. Indeed, though the quite small. terms as principle, acid and base, or combustible and sup- In other words, classical chemical analysis depends on porter, continued to be used into the third and fourth decades more than the definition of simple substances and the law of of the century, they gradually ceased to imply the necessary conservation of mass provided by Lavoisier. It also requires an existence of certain properties in the substances so labeled empirical knowledge of the interconversions of different (such as sour taste in the case of acids) and became instead materials and an extensive mapping of the reactivity matrix, indicators of their taxonomic positions in the reactivity matrix. much of which, as the study of late 18th century analytical Thus the debates over the nature of acids in the 1830's had little chemistry has shown, was done prior to the work of Lavoisier, or nothing to do (as so often misrepresented) with the question whose contributions can in many ways be viewed as a set of of whether oxygen or hydrogen was the true acidifying prin- rules for guiding the chemist through its manifold pathways ciple; rather they dealt with competing theories of salt forma- (29). Indeed, the history of the discovery of new elements tion, which is to say, with competing views of the taxonomic clearly shows that use of the reactivity matrix can even allow relationships between these substances in the reactivity matrix chemists to infer the existence of new elements through the (e.g., do acid and bases form salts via addition or via displace- behavior of their compounds (usually the oxides) without ment reactions ?) (26). having actually isolated the element itself (30). Consequently, as suggested earlier, there was no explicit Lastly, it is of interest to note that, with the advent of the confrontation with the chemistry of principles. It simply faded electronic theory of matter and the instrumentation revolution, away, along with the importance of relation 1 as an approach modern chemistry has again returned to a left to right reading to determining composition. Though Lavoisier failed to deal of relation 2 and direct physical methods of analysis are rapidly directly with the issue of principles and properties, he nonethe- replacing the methods of classical chemical analysis. On the less provided chemists with the tools that would eventually other hand, the reading of relation 2 from right to left, which direct their energies into a more fruitful approach to the prob- may be interpreted as a form of "molecular engineering" and lem of compositon. By the time the property-composition which is, in some sense, a modern equivalent of the alchemist's problem was revived in the second half of the 19th century and dream, still remains very much an open problem for 20th correctly reformulated as: century chemistry.

properties = f (composition and structure) (2) References and Notes

the newer generation of structural organic chemists was no . S, fr xpl, th rnt n A. nvn, Ed., "h longer aware of the details of the earlier program and, with the Chl vltn: E n ntrprttn", Or, 1988, 4. accumulated fruits of Lavoisier's approach to composition to 2. Qtd n . Shnn, nd, nd Chrhd Mth build upon, it seemed almost inconceivable that their program f Arn tr, Mrr, Yr, Y, 88, p. . was anything other than the completion of his own (27). . r n rl th ntr xpl, . C. , A Mnl In passing, it is of interest to note that there is evidence that f Chtr, n, Yr, Y, 88, p. . Al th nt it took chemists several decades to learn how to make full use n rfrn 24 n htr "pf" ph. r 20th ntr of the implications of Lavoisier's approach to composition xpl, W. Otld, rnpl f Inrn Chtr, M and, even to this day, it is misrepresented in both chemistry lln, ndn, 4, pp. . texts and in the history of science literature. Both sources 4. . . Oldrd, "h trn f rprtCnfrrn rn generally imply that what is involved in analysis is the simple pl n Chtr: Orn nd Antdnt", Ornn, 1970, 2 separation of a substance into its component elements. How- , . ever, as anyone who has practiced classical chemical analysis . C. E. rrn, "vr bl f th Elnt: A knows, this is seldom the case. What one actually does is to pprl", Abx, 1973, 20, . 48 ll. t. Ch. (8

6. A. vr, Elnt f Chtr, Crh, Ednbrh, l., Ednbrh, 806, pp. 2. 0, p. . 26. r td f th tr "d" n th pr f trntn, . . Sfrd, "vr bl f Spl Sbtn: It W. . nn, "brt r nd th f l n Ar", Orn nd Intrprttn", Abx, 1982, 2, 2. t b pblhd. 8. r th dtl f Mthll lf nd pbltn, W. B. 2. r r f th plhnt f th th ntr nn, "h hé Mthll, CIACS, 1988, 2(, 6 nd ht n th r , S. Sl, h ltn tn Chl 26(, 0. Cntttn nd S hl rprt, nn, Grn nd . W. . Ml, "h Clbn Chl St", Ch, C., ndn, 0, nd . Kffnn, zhnn hn 1959, , 4. hlhn Enhftn nd Chhn Kntttn, En, 0. W. . Ml, "Erl Arn Chl St", Ch, Stttrt, 20. 1950,3, . Al W. . Ml, "hn dn Cx nd th ndn 28. S rfrn 24, p. 88. f th Chl St f hldlph n 2",ll.t.Mdn., 2. . W. ln, "A Cntrbtn f trl tr t th Ch 6,0, 46 nd . C. ltn, "Erl Arn Chl St", l vltn n rn", Abx, 1985, 2, , nd . Cb p. S. Mnthl, 1897, , 8. nd G. Kffn, "h Anltl Cnpt f Chl Elnt n . . . Mthll, "r n th hlt nd Antphl th Wr f rn nd Shl," Ann. S., 1976, , 44. t St f Chtr, M. Clbn Ch. S., 1813, , 2 0. S th nt n M. E. W, vr f th Elnt, . r rtr lrt, Mthll pnttn h bn prtl 6th d., . Ch. Ed., Etn, A, 60. drnzd n f th ttn. . E. Crr, Sbtn nd ntn, Opn Crt, Ch, 2. . . Mthll, "Anl f rfr Cx E n I, 2, p. . Cbtn nd Adftn", M. Clbn Ch. S., 1813, , . . frn 2, p. 88. Dr. William B. Jensen holds the Oesper Position in History of 2. . . Mthll, Elnt f Chl hlph, Cr nd Chemistry and Chemical Education at the University of rbn, Cnnnt, O, 82, pp. 444. Cincinnati, Cincinnati, OH 45221. He is interested in the . . Sfrd, "An Attpt n th Untd Stt t lv th history of inorganic and physical chemistry and in the devel- ffrn tn th Oxn nd hltn hr", I, opment of the 19th century Cincinnati chemical community. 1955, 46, 2. 6. . h, "An Enr nt Wht Crtn Wll Wr rnt U t tl n An Sbtn rnpl f Cn rprt f An St f d", M. Clbn Ch. S ., 1813, A IOGAICA CECKIS , . . r d nl f th prprt prbl lr t The following is a checklist of biographies of Lavoisier n the tht f Mthll, A. Mll, Sp nd n Chtr, , Oesper Collection in the History of Chemistry at the University ndn, 6, pp. . of Cincinnati. For teachers and practicing chemists looking for 8. r th dtl f Sl lf nd r, W. B. nn, brief, accessible introductions, Guerlac (1975), McKie (1952) "Eljh Sl", CIACS, 1989, 26(2, 8 nd 26(, 8. and Davis are recommended. For more scholarly detail on . E. Sl, A K t th hnl n nd Othr specific aspects, Guerlac (1961) and Holmes are recommended. fflt f Chtr r Chl nltr, Wlln, Cnnnt, O, 828. A. r, vr, Wn, 06. 20. . 1. vn nd H. S. Kltn, "h Intrdtn f M. rthlt, évltn Ch vr, Grr vr Chl nltr nt Ar", I, 1954, 4, llèr, r, 80. 28 nd 68. M. rthlt, t tr r vr, Adé d 2. W. . nn, h Ad Cnpt: An Ovrv, Sn, r, 88. Wl Intrn, Yr, Y, 80, Chptr . . A. Chrn, vr, Cntbl, ndn, . 22. . ,AnECnrnn nUndrtndn (60, M. Crlnd, értr d vr, l d l évrt, Oxfrd Unvrt r, Oxfrd, . r, 68. 2. . Alxndr, Id, Qlt nd Crpl, Cbrd C. Cttlt, prtn nd th vr rdtn, Arn Unvrt r, ndn, 8: hlphl St, hldlph, A, 2. 24. A. . rr, A Gnrl St f Chl Knld M. , vr, Gllrd, r, 4. nd It Appltn t th hnn f tr nd Art, l. , M. , vr, hérn t Expérnttr, r Cdll, v t. l, ndn, 804, pp. 020. I ld l t Unvrtr d rn, r, . thn r. Sr Mpf fr brnn th r t ttntn. K. S. v, h Ctnr Sntt: rtl, vr nd 2. . Mrr, A St fChtr, l. , nn, rt, t. th ndn f Mdrn Chtr, tn, Yr, 66.