Research: Science and Education
The Role of the Laboratory in Chemistry Instruction M. J. Elliott, K. K. Stewart, and J. J. Lagowski* Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712; *
[email protected] Although nowadays few instructors would consider offering a course in basic chemistry without a laboratory component, that has not always been the case. The apparent need for laboratory instruction in chemistry has been essentially instinctive among teaching chemists; it appears to be a part of their psyche. Precious little direct evidence exists that such instruction provides a useful function in the way(s) students learn chemistry. In spite of this anomalous behavior of scientists in their apparent lack of interest in data supporting their behavior, most academic chemists, and indeed industrial chemists also, will swear fealty to some concept relating laboratory instruction to the formal teaching of chemistry, especially at the undergraduate level. The historical roots of this idea and its theoretical foundation are presented here in an attempt to bring clarity to a subject on which almost everyone has an opinion or a theory. Basic questions concerning the role of laboratory experiences in the learning process for chemistry—or, indeed, any laboratory in any science—persist. Here we continue to pursue our on-going interest in understanding the role of laboratory instruction in the educational process(es) associated with learning chemistry, specifically in the laboratory experience for undergraduate science majors.1 Historical Antecedents The evolution of laboratory instruction is difficult to separate from the historical development of the discipline. If chemistry were to be found in an 18th century academic institution, it would be classified under natural philosophy; many of the subject’s practitioners were medical doctors. Natural philosophy is the term applied to the objective study of nature and the physical universe. From our perspective, natural philosophers were scientists—astronomers, physicists, chemists, biologists, and so forth. Science was simply a synonym for knowledge or study. Chemistry, as we know it, did not exist before Lavoisier (1743–1794). The wealth of facts that had been accumulated by the practitioners of the chemical arts were gathered by Lavoisier and others and interpreted correctly to start what some have called “the chemical revolution”. Before this period, the chemical arts were usually an adjunct to medicine and the best place to learn the “doing” of the chemistry of the day was in a pharmacist’s shop or, perhaps, in the mining trade. Practical instruction in the chemical arts was generally not available in an academic setting, although many of historically notable chemists of the time gave lectures in academic institutions; lucky students in those courses might be invited to work in the professor’s private laboratory. In some cases, academicians gave private laboratoryoriented courses of instruction. It was these academicians who were “doing the research” that was needed to move chemistry along the path defined by Lavoisier; their research was accomplished in private laboratories with the help of assistants.
Teaching Laboratories The chemical milieu of the times can be summarized as an emerging science struggling with, at least, three concepts; how to do the research necessary to move the subject forward, a need for precise composition analysis, and the training of novice chemists on the appropriate laboratory skills. Friedrich Stromyer first began offering laboratory instruction to students in Göttingen in 1806; J. N. von Fuchs in Landshut in 1802; Döbereiner at Jena after 1811; N. W. Fischer at Breslau after 1820 (1); and Liebig at Giessen in 1824. Liebig’s laboratory-oriented teaching methods stand out among this group because his methods seem to be the antecedents of those found in the modern graduatelevel chemical research program. As Liebig observed (2), “At that time, chemical laboratories in which instruction was given in analysis did not exist anywhere; what people called such, were rather kitchens, filled with all sorts of furnaces and utensils for carrying out metallurgical or pharmaceutical processes. Nobody understood how to teach analysis.” Although he is remembered as an organic chemist, Liebig recognized the importance of analyses, which led to formulas for substances; early laboratories were focused on what we, today, might call synthesis of new substances or the isolation of pure substances from naturally occurring mixtures. Liebig may have been the right person at the right time in the evolution of chemical thought because of his focus on analysis of organic substances. Organic analysis, the predominant research tool of the times, produced empirical formulas that revealed an inner structure of the subdiscipline called organic chemistry. Liebig, together with Wöhler, was among the leading chemists of the 19th century who helped make organic chemistry a field of systematic study within the framework of the known chemical laws. Liebig’s method(s) for the precise analysis of organic substances produced the data that led to the concept of radicals—groupings of atoms in organic compounds that retain their identity, even when those compounds are transformed into other substances. The identification of radicals can be seen as an early step along the path to modern structural chemistry. From this perspective, it is reasonable to imagine that Liebig had more ideas than he had hands to collect the experimental evidence necessary to test them; he had a need for students who could do reliable chemical analysis. It is easy to imagine that Liebig established the teaching laboratories in Giessen to help him further his research interests. The teaching laboratories produced well-trained chemists (technicians?) who could, in turn, produce empirical formulas. That point of view is consonant with the training students received in Liebig’s Giessen teaching laboratories, which history indicates were built to his specifications and supported by the university. Putting this situation in modern terms, the university provided for the support of Liebig’s research interests; all he had to do was to turn these resources to his advantage, which he did by creating analytical
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teaching laboratories, not laboratories designed for synthesis work or any other chemical subject. The teaching model for students in these labs is a version of the apprenticeship process. Novice students were given 100 substances (3) of known composition to analyze using Liebig’s methods as described in a laboratory manual he had written (Anleitung zur Analyse Organischer Korper); examination of an English translation of that manual (4) shows that the “manual” is really a very detailed description (59 pages) of how to do analysis by measuring the amount of H2O and CO2 produced in the complete combustion of organic substances. Students in the course learned all the details of basic chemical processes and combustion analysis under the supervision of one of Liebig’s assistants. Liebig gave the younger students little personal instruction in the basics of laboratory processes; this was the task of the older students to act as mentors to guide the beginners in their work. The older students worked on original problems, turning in a report each morning on their progress the day before. These reports were discussed by Liebig with the various students in planning their future work. When the beginning students successfully completed the analysis of the 100 standard substances, they were considered capable of working on individual research problems supervised by Liebig, which involved the analysis of new substances prepared, isolated, and purified by Liebig. Liebig was, indirectly, active in the formal training cycle of the novice students by inventing apparati and procedures that permitted students to perform analyses more efficiently; it is reported that his kaliapparat (5, 6) allowed students to perform four hundred analyses per year. Consider the implications of training 5–10 students each year in a time-on-task environment where each student will perform hundreds of analyses. This environment was certainly capable of producing expert analysts each of whom, in addition, can produce internally consistent data on, at least, tens of new compounds each year. Liebig had the capacity to disseminate the work of his students because he was also the editor of Annalen der Pharmacie (which was replaced by Amelan der Chemie and Pharmacie); in a single year, Liebig’s students published 32 articles in this journal. It is not surprising that Liebig’s teaching laboratory regularly drew foreign visitors as laboratory assistants who wanted to learn about the techniques that yielded such an enormous volume of research-level results. Liebig’s Giessen laboratory exerted a pre-eminent influence on the training of chemists for nearly 50 years and his methods influenced the progress of chemistry around the world. The perceptive reader will recognize in this description of Liebig’s Giessen laboratory echos of the modern university chemical research laboratory for graduate students. In the Domin classification scheme for instructional laboratory experiences (7), Liebig’s style of laboratory instruction would have to be described as “inquiry” or “problem-based” because these kinds of experiences are intended to help students develop true research skills and strategies. When Liebig established his laboratory teaching methods (1811), the British American colonies had been established and had gained their freedom from the Crown. The art of chemistry was important in colonial times for the production of substances necessary in the everyday lives of the colonists, for example, salt, iron, glass. The manufacture of glass implied access to local supplies of potash, which was obtained from wood ashes, a well-known art.
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The evolving chemistry of the times was introduced to the colonies by physicians trained in the European manner and who were starting medical schools in America. Thus, Americans were following paths parallel to those developing in the “old countries”. Infusion of ideas from the latter occurred through occasional visits by Americans to Europe. A lack of proper equipment, chemicals, and the most modern books were additional burdens for American chemists. Not surprisingly, the colonists also had established academic institutions starting in the last quarter of the 18th century. Before 1820, about forty colleges and universities had been established; about half of these offered courses in chemistry (8). Early on, chemistry was taught as a part of natural philosophy, but then its teachers evolved to professors of chemistry, who were, for the most part, physicians. The first professor of chemistry in America was Benjamin Rush (1745–1813) who taught chemistry in the Philadelphia Medical School as early as 1769. From one point of view, Rush can be considered as the “conduit” of European chemical education of the times (late 18th century) to America. He was born an American, obtained his B.A. degree at the College of New Jersey (now Princeton University), and obtained a medical degree at the University of Edinburgh. While at Edinburgh he studied chemistry for two years with Joseph Black, also a physician, but also an important figure in the development of the science of chemistry. In 1770, Rush published Syllabus of a Course of Lecture in Chemistry, which is probably the first textbook of chemistry by an American published in America (9). Thus, the American development of chemistry instruction fell into step with the processes occurring in Europe. The ongoing connections to the development of chemistry occurred via study tours by Americans who had the means to travel and an interest in learning about the medical arts and the applications of the chemical arts for commercial reasons. If Americans were to succeed personally and nationally, they had to connect to developments in Europe, and this could only be done effectively face-to-face. Laboratory instruction in the American milieu was still an apprentice-like experience, but perhaps not so organized as was Liebig’s system. American Academic Laboratories Initially, actual laboratory instruction of students was limited, as was the case in Europe. At most of the American academic institutions where chemistry was taught, students watched the professor of chemistry do experiments (not demonstrations); they were not permitted to handle apparatus. Privately owned laboratories offered one of the best openings to chemistry students who desired to become familiar with methods of chemical analysis. Two such privately owned laboratories were opened in 1836: in Boston by Charles Thomas Jackson (10, p 99) and in Philadelphia by James Curtis Booth (10, p 99). The credit for establishing the first regular laboratory chemistry course at an American institution of higher education—Yale University— probably goes to Benjamin Silliman, the younger, in 1842; the subject of the course was chemical analysis. As an aside, a great deal of interest in America of Liebig’s work was generated by the publication of Liebig’s “Treatise on Agricultural Chemistry”. That subject had great practical appeal in a country that was concerned with developing its capacity in agriculture. Based on the success of Silliman, the younger’s, course, and the growing interest in agricultural chemistry, Silliman, the elder,2 convinced
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Research: Science and Education
the Yale College Corporation3 to establish a school of science in 1847, later named the Sheffield School of Science after an important Yale benefactor. In the same year as the foundation of the Sheffield School at Yale, the Lawrence Scientific School in Boston was established as a part of Harvard University. Thus, in that year, the availability of student places in formal institutions of higher learning for chemical laboratory instruction went from zero to tens of students. Almost immediately, the Lawrence School came under the influence of Liebig’s ideas, when Eben N. Horsford was made its director (10, p 177). Horsford had just returned from his laboratory training at Giessen under Liebig! Harvard was also the nexus for bringing laboratory instruction in chemistry and physics into the secondary school curriculum through the agency of Charles W. Eliot who was, in order, assistant professor of chemistry at the Lawrence School, acting dean of that institution, professor of chemistry at the newly founded Massachusetts Institute of Technology (MIT), and president of Harvard University in 1869. It was in that last position that Eliot revolutionized the teaching of science in America by implementing chemistry and physics as mandatory entrance requirements (11) to Harvard. Completion of specified high school experiments would entitle entering students to receive admission credit and, perhaps, advanced study in these subjects. As a result of this action, high schools created new laboratory courses featuring individual laboratory work. For a useful detailed discussion of this fortuitous collection of events see ref 10. The successful struggle to include a laboratory experience in the early courses in the chemistry curriculum in high school and college chemistry neglected to recognize the importance of the content of these laboratory-oriented courses. For example, the manual by Nichols (1872) (12), which was an abbreviated version of Eliot and Storer’s manual has the experiments embedded in the textbook; the manual by Remsen (13a) is closely associated with his textbook (13b). The experiments in these manuals are clearly expository in nature using Domin’s classification (7). Thus, the Liebig’s research-oriented laboratory experience was converted in America into an expository experience with all of the current implications of that description. Function of Laboratory Instruction Since Liebig’s time, laboratory instruction in chemistry has been universally viewed as an important part of the chemistry curriculum from the high school (14) through the graduate programs. The idea that chemistry implied laboratory work grew steadily, but the kind of laboratory experience had not been established on the American scene. Arguably, the discipline might not have developed as quickly as it did through the 1800s without the approach attributed to Liebig that produced research quality data as well as capable and competent chemists. The facts of chemistry were being consolidated into bigger ideas, concepts, and theories by Liebig and other “research” chemists of the time. In order to establish an overarching philosophy for the discipline, sufficient observations had to be collected to create the larger message. The facts of chemistry had become significantly numerous to allow their consolidation into the larger concepts about which lectures could be logically organized, and the bulk of the formal instructional process could be done in that more efficient (but
not necessarily more effective) format. The basic knowledge in chemistry could easily be transmitted through lectures; the Liebig laboratory experiences could train students on how that knowledge was obtained. While lecture-oriented instruction in chemistry has become largely standardized through organizing the course by way of major concepts and theoretical principles rather than descriptive chemistry (15), the nature of laboratory instruction in chemistry from institution to institution, and even between laboratory courses within an institution, has become widely divergent, which may be the result of an ever-widening understanding of chemistry. Indeed, some chemists now believe that laboratory instruction in chemistry has been rendered irrelevant (16). The Liebig model—the training of students to produce research quality data—does not seem to be applicable at the undergraduate level because the tools and techniques used in modern chemistry are well beyond the grasp and interest of novice students taking chemistry courses. Currently, the Liebig apprenticeship model is well expressed with more mature students—graduate students—who are the modern equivalent of the students taught at Giessen. For a great many years, organized laboratory activities have been regarded as a critical part of the education of chemists. The laboratory experience is viewed by many as the essence of science. Yet the available evidence for the past half century, at least, suggests that laboratory activities fall short of achieving the potential for enhancing student learning with understanding (17). Future of Laboratory Instruction An inspection of the possible individual factors that appear to be related to laboratory instruction (vide supra) produces a jumbled mosaic and not necessarily a unified whole analytical picture. So, perhaps, a better description of the role of the laboratory can be derived from the roots of this discussion—Liebig. Liebig, like all practicing chemists, was interested in solving the complex chemical problems of his day. In retrospect, these problems that were focused on analysis seem trivial today, but only because we have the advantage of the hindsight of history. If we consider how chemists deal with the complex “chemical problems of the day”, the answer most often is through research. And chemical research can be characterized as learning to think about how to systematically solve complex problems requiring multiple steps to gain the solution. The multiple steps usually require the repeated application of tools—both sophisticated manipulative and detailed cognitive tools grounded in theory. To acquire skills using those tools requires repetition, probably to the extent of boredom. The most effective means of overcoming boredom is to gain such skills in a greater, more interesting context to the student. In other words, to show the student the importance of gaining such skills in a research context. Then, the results of using such skills can be expressed as a part of their integration into the solution of a problem that is meaningful to the student. Thus, the continuation of the successful Liebig legacy seems to be embodied in its current manifestation at the post baccalaureate level—the graduate program at most institutions offering advanced degrees in chemistry. The usual undergraduate chemistry programs are not, however, necessarily devoid of a research experience.
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For example, the National Science Foundation (NSF), through various programs, supports initiatives that place research-grade equipment in small colleges and universities with the expectation that lower-division undergraduate students will use these instruments. The fact that the NSF has taken on this initiative suggests that it sees value in Liebig’s approach, namely, having students work on authentic modern-day chemistry problems that require tools more sophisticated than those required by Liebig to do organic elemental analysis. The most recent NSF initiative to engage undergraduates in a research experience is the Undergraduate Research Collaboratives (URC). The Ohio REEL project (Research Experience to Enhance Learning) is designed to provide a laboratory-based research experience through the development and implementation of “research modules” that are to be integrated into first- and second-year chemistry courses (18). At Purdue, NSF is supporting another multi-institutional undergraduate initiative through the Center for Authentic Science Practice in Education (CASPIE), the goal of which is to provide first- and second-year students with access to research experiences as part of the mainstream curriculum (19). Arguably students in such programs gain a marketable skill as well, but it is a fact that instrumentation is the basis of advancing the discipline by its natural method, research, that makes these programs so valuable; experience in that kind of instrumentation generally is not possible with the numbers of students for which we have a responsibility. Additionally, the Council for Undergraduate Research (CUR) encourages faculty in many disciplines, not just chemistry, to provide opportunities for students to engage in research. These programs are by necessity an apprenticeship; the faculty member must work one-on-one with each student, assisting students to ply their respective trades. We believe that it is possible to begin to help undergraduates experience a research ambience in the context of a standard first-year chemistry laboratory course using the Cognitive Apprenticeship Theory (20) as an organizational template (20). The Cognitive Apprenticeship Theory describes a pedagogical model developed within the situated learning paradigm. The theory is inspired by the apprentice master model of traditional crafts commonly found in non-formal instructional environments, but it has been adapted to cognitive or intellectual domains. The theory describes the details of a learning environment in terms of four dimensions—content, methods, sequence, and sociology. Thus, the formal course-oriented laboratory environment can be manipulated to maximize that environment to help students learn chemistry from a research laboratory perspective. Previously, we have described (21) the details of an entry-level laboratory course that provides many of the research-oriented experiences that lead to deep learning of the subject. The nature of research, not just in chemistry but in any science, is inductive. The outcome of research is not predetermined or known. Research involves capitalizing on previous knowledge and skills, but unlike many of the typical formats of laboratory instruction, research is focused on a narrow problem, explored in depth, rather than being a collection of unrelated (expository) experiments. Laboratory experiences intended to mimic the research experience should not involve a series of disparate experiments but rather a sequence of experiences as part of a coherent whole. A detailed description of such a course as well as an evaluation of its effectiveness is forthcoming.
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Acknowledgement We gratefully acknowledge the generous support of the Robert A. Welch Foundation. Notes 1. We are, perhaps, remiss in separating the large cohort of nonscience majors who take chemistry, but, in our view, the intellectual needs of these students are different from those of the science majors. The answer to the question of a laboratory experience for nonscience majors is best left for another time. 2. The Sillimans, father (Benjamin, the elder) and son (Benjamin, the younger), were profound early influences on the development of sciences not only at Yale University, but in the United States as a whole. Silliman, the elder (1779–1864), often described as a “geologist”, was appointed to Yale College’s new professorship of chemistry and natural history in 1802. It is reported that he left for two winters to study at the Medical College of the University of Pennsylvania, and in his spare time he and chemist, Robert Hare, performed experiments in a laboratory that they set up in a cellar kitchen of their boarding house. After that experience, he concluded that chemistry could not easily be self-taught. His appointment at Yale included natural history, which was understood to cover geology, mineralogy, botany, and zoology. To fill the gaps in his knowledge, he spent 1805 and 1806 in England and Scotland. He emerged from these years of study with a solid background in theoretical and experimental chemistry. Silliman, the elder, grew to become a source of great influence in Yale. Silliman, the younger (1816–1885), was also a professor of chemistry at Yale. His contribution to chemistry was the work he did on the fractional distillation of the components of “rock oil” (now known as petroleum) that had been found in western Pennsylvania. Silliman, the younger’s, report on his work concluded that “rock oil is a raw material from which…they may manufacture a very valuable product”; distilled petroleum (kerosene) burned far brighter than any fuel on the market, except those that were far more expensive. All this activity evolved in parallel with their work on the processes of teaching chemistry. 3. Yale University comprises three major academic components: Yale College (the undergraduate program), the Graduate School of Arts and Sciences, and the professional schools.
Literature Cited 1. Ihde, A. J. The Development of Modern Chemistry; Harper and Row Publishers: New York, 1964; p 261. 2. Lockemann, G.; Oesper, R. E. J. Chem. Educ. 1953, 30, 202– 206. 3. Good, H. G. J. Chem. Educ. 1936, 13, 557–562. 4. Liebig, Justus. Instructions for the Chemical Analysis of Organic Bodies; Gregory, William, Translator; Richard Griffin & Co.: Glasgow, 1839. 5. Morrell, J. B. Ambix 1972, 19, 1–47. 6. Ihde, A. J. The Development of Modern Chemistry; Harper and Row Publishers: New York, 1964; pp 179–183. 7. Domin, D. S. J. Chem. Educ. 1999, 76, 543–547. 8. Newell, L. C. J. Chem. Educ. 1976, 53, 402–404. 9. Goodman, N. G. Benjamin Rush, Physician and Citizen (1746– 1813); University of Pennsylvania Press: Philadelphia,1934; p 31.
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Research: Science and Education 10. Silliman, Benjamin, Jr. “American Contributions to Chemistry.” An essay prepared for the Priestley Centennial Celebration at Northumberland, Pa., in 1874 and published in The American Chemist 1874–1875, 5, 70–114, 195–209, 327–328. 11. (a) Rosen, S. J. Chem. Educ. 1981, 58, 1005–1006. (b) Sheppard, K.; Robbins, D. M. J. Chem. Educ. 2005, 82, 561–566. 12. Nichols, W. R. Elementary Manual of Chemistry; Ivison, Blakeman, Taylor and Co.: New York, 1878. 13. (a) Remsen, Ira. A Laboratory Manual; Henry Holt and Co.: New York, 1898. (b) Remsen, Ira. The Elements of Chemistry; Henry Holt and Co.: New York, 1887. 14. Sheppard, Keith; Horowitz, Gail. J. Chem. Educ. 2006, 83, 566–570. 15. Lloyd, B. W. J. Chem. Educ. 1992, 69, 633–636. 16. Hawkes, S. J. J. Chem. Educ. 2004, 81, 1257. 17. (a) Hofstein, A.; Lunetta, V. N. Science Education 2003, 88, 28–54. (b) Tobin, K. School Science and Mathematics 1990, 90, 403–418. (c) Hofstein, A.; Lunetta, V. N. Rev. Ed. Research 1982, 52, 201–217. (d) Tobin, K.; Gallager, J. J. J. Curriculum Studies 1987, 19, 549–560. (e) Herron, J. D. Nurrenbern, S. C. J. Chem. Educ. 1999, 76, 1353–1361. 18. Research Experiences to Enhance Learning. http://www.ohio-reel. osu.edu (accessed Oct 2007).
19. The Center for Authentic Science Practice in Education. http:// www.purdue.edu/dp/caspie (accessed Sep 2007). 20. (a) Collins, A.; Brown, J. S.; Newman, S. E. Cognitive Apprenticeship: Teaching the Crafts of Reading, Writing, and Mathematics. In Knowing, Learning, and Instruction: Essays in Honor of Robert Glaser; Resnick, L. B., Ed.; Lawrence Erlbaum Associates, Publishers: Hillsdale, NJ, 1989. (b) Stewart, K. K.; Lagowski, J. J. J. Chem. Educ. 2003, 80, 1362–1366. (c) Stewart, K. K.; Elliott, M. J.; Lagowski, J. J. Cognitive Apprenticeship Theory and Graduate Education. In Am. Chem. Soc. Abstracts, 223rd ACS National Meeting, Orlando, Florida, April 2002; CHED Abstract 1134. 21. Elliott, M. J.; Stewart, K. K.; Lagowski, J. J. Teaching Future Scientists Laboratory Chemistry using Cognitive Apprenticeship Theory. In Am. Chem. Soc. Abstracts, 223rd ACS National Meeting, Orlando, Florida, April 2002, CHED Abstract 1133.
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