The chemistry of the founding fathers - Journal of Chemical Education

The chemistry of the founding fathers. John J. Beer. J. Chem. Educ. , 1976, 53 (7), p 405. DOI: 10.1021/ed053p405. Publication Date: July 1976. Cite t...
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John J. Beer University of Delaware

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The Chemistry of the Founding

In the very years that the English colonies were established on the Atlantic seahoard, chemistry was evolving away from Renaissance alchemy and acquiring an identity of its own as a branch of natural philosophy on a par with physics, mathematics, and astronomy. By 1650 chemical philosophers had come under the influence of Francis Bacon who had urged rational empirical inquiry into nature and the manufacturing crafts for the sakeof ultimately improving the health and comfort of mankind. In Bacon's own pithy words: "Nature to be commanded, must be obeyed." It was in this spirit that the English colonists approached the chemical arts. However, frontier conditions provided less time for scholarship and fewer scientific resources than had been availahle in the mother country. Sustained experimentation and dialogue with knowledgeable colleagues was impossible until after 1875 when, to paraphrase Benjamin Franklin, the first drudgery of settlement was pretty well over and there were in a few cultural centers enough gentlemen of leisure and wealth to support institutions of learning that disseminated the latest scientific intelligence from Europe and added, however modestly, to the common stock of knowledge (1). Right from the beginning, the British colonists engaged in nroductive o~erationswhich form Dart of what we today c a i the chemiEal industry. They prospected greedily f& cold and silver but their assavs revealed onlv scattered de" posits of copper ores too insignificant in size to smelt here so they shipped them to England for processing. Iron ore was much more abundant and was eventually smelted in every colony. Iron was usually consumed domestically hut by mid-eighteenth century the mid-Atlantic colonies were exporting sizable amounts to England and other British colonies (2). From their abundant forests the colonists ohtained pitch and tar for waterproofing and preserving the hulls of ships. From wood ashes they leached potash. This alkali found use in cleansing textiles, the making of soap, glass, and saltpeter. Saltpeter in turn was incorporated with sulfur and charcoal into gunpowder. Lime was burnt and found multiple uses in agriculture, whitewash paint, mortar, in making glass, and for dehairing hides prior to tanning. Leather was so indispensable for shoes, straps, harnessing, satchels, clothing, and even hinges that no settlement was long without its tannery. Tanning required large quantities of tan hark and alum. Alum, a complex double salt usually of potassium or ammonium aluminum sulfate, also found use in medicine as an astringent and in textile dyeing as a mordant. Some Old World dyes like indigo were grown and extracted in the southern colonies, others were made from newly discovered American plants. For example, sumach and quercitron gave yellow shades and tan, respectively (3). When mixed with iron sulfate (copperas), sumach yielded a strong black dye also useful in making inks (4). With the passage of time an increasing number of medicinals and chemicals sold by pharmacists were compounded in their own shops. I refer to such items as cosmetics, solvents, mineral-acids, pigments, and drugs of all kinds, like sal ammoniac (a mixture of ammonium chloride and ammonium carbonate) sold as smelling salts, and to tin smiths as a flux for soldering. All this practical chemical knowledge came to our shores stored in the minds

of immigrants or was carefully noted by colonists on visits to Europe. I t was supplemented by the continuing flow across the Atlantic of correspondence, learned hooks, and technical manuals like that of Thomas Stephens, "The Method and Plain Process for Making PotAsh," London,

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In no chemicallv related enterprise were books as vital and as regularly consulted as in medicine and pharmacy. I estimate that publications purchased in these related disciplines exceeded in number all other chemical treatises taken together. This medically oriented chemical literature was also more likely to concern itself with chemical theory. Thus i t often did double duty as a practical manual and as an academic text. Indeed, chemistry, as generally perceived in the seventeenth and eighteenth centuries, was identified most closely with medicine and pharmacy. As an academic subject it was taught most extensively and rigorously in medical colleges. Since the first of these was founded only in the year 1765, we see at once that formal instruction in chemistry is a late colonial phenomenon.

.. frontier conditions provided less time for scholarship and fewer scientific resources than had been available in the mother country. Prior to the start of graduate medical education, some chemistry had been taught to undergraduates in the liberal arts at Harvard, Yale, William and Mary, and in the institutions we now call Princeton, Columbia, and the University of Pennsylvania. But the study of chemical principles formed only a modest part of a general course on natural philosophy. Natural philosophy was usually taught to seniors after they had acquired in the three years previous what was considered proper grounding in Latin, Greek, rhetoric, religion, philosophy, logic, and mathematics. Initially only about 10% of the liberal arts curriculum in colonial colleges was devoted to science but as the eighteenth century advanced, this proportion increased a t all these schools. most markedlv at the College - of Philadel~hialater renamed the University of Pennsylvania-where 40% of the curriculum was devoted to science (5). The central object of all undergraduate courses in natural ~hilosovhvwas to understand Newtonian astronomy and'physics. The supreme ambition of colonial science students and scholars was to master Newton's mathematics of fluxions (calculus) and to fully understand his "Principia." Only a handful of Americans achieved that distinction hefore 1800. As interest in Newtonian science deepened, the college courses in natural philosophy became increasingly devoted to physics and this eventually necessitated the establishment of separate courses in astronomy and chemistry. Thus the first course exclusively devoted to chemistry at the undergraduate level was established in 1757 at the College of Philadelphia. I t was taught by the school's first provost, William Smith (1727-1804). Smith was an Anglican clergyman, born in Reprinted from Transactions of the Delaware Academy of Sciences, (1976)with permission of the editor, J. C. Kraft. Volume 53, Number 7, July 1976

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Scotland, with degrees from Aberdeen, Oxford, and Trinity College in Dublin. He was hand-picked by Benjamin Franklin, a trustee of the College, because he was well schooled in science. Smith made the study of science mandatory of all undergraduates. His course on "Chemistry, Fossils and Agriculture" was taught daily in the last semester before graduation (6). Similar chemistry courses for seniors were subsequently introduced a t the College of William and Mary in 1774 by the Rev. James Madison, a t Harvard in 1787 by Charles Morton, and at Princeton by John Maclean in 1795 (7). But as mentioned earlier, the most advanced teaching and study of chemistry took place not in the liberal arts colleges hut in the late colonial medical schools. The first of these was the Philadelphia Medical College which between. 1779-1791 was merged with the city's undergraduate college into the University of Pennsylvania. From the year of its founding in 1765 a course in chemistry and materia medica was taught annually hy the new medical school's founder, Dr. John Morgan. Morgan was no specialist in chemistry hut he had first studied that subject a t the College of Philadelphia under Provost William Smith and later taken more courses in chemistry a t the University of Edinburgh where he had gone to study medicine. During the eighteenth century Scottish universities were more progressive in their teaching of science and medicine than were Oxford and Cambridge. Morgan's chemistry professor at Edinburgh, William Cullen (1712-1790), taught the subject "not as a mere adjunct to medicine, hut as a science entitled t o recognition on its own merits" (8).The Scottish approach to science soon came to dominate chemical and medical education in America as graduates from Glasgow, Edinburgh, and Aherdeen filled other chairs being founded in these fields a t American colleges and universities. For instance, it was not long after returning to Philadelphia to teach that Morgan urged one of his best students, Benjamin Rush, to study medicine in Scotland with emphasis on chemistry so that Rush would eventually be a strong candidate for a professorship in chemistry which Morgan hoped to establish at the Medical College. I t all worked out as Morgan and Rush had hoped. After studying chemistry at Edinburgh with Joseph Black, the discoverer of the idea of latent heat and of carbon dioxide ("fixed air"), Rush came hack to Philadelphia in 1769 to assume the first chair exclusively created for chemistry in North

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In his zeal to secure the appointment Rush had written to Morgan, "I should like to teach chemistry as a professor

because I think I could show its application to medicine and philosophy in a stronger light than ever has yet been done" (9). But once the course got under way it was little more than a carbon copy of the lectures he had heard Joseph Black deliver a t Edinshurgh. Nor did his lectures change very much over the years. The 1770 edition of his Syllabus of a course of lectures on chemistry1 differs little from that published 13 years later. And yet i t was a good course on a par with the better chemistry courses given in Europe. Its content, therefore, tells us a lot ahout the approach to chemistry a t the time of the Revolution. According to class notes taken in 1771 by Francis A l i ~ o n Rush ,~ devoted his first lecture to the indis~ensahilitvof chemistrv to medicine. Chemistry, he expiaim, is the key to understanding "the laws of Animal Aeconomy." I t describes the effects on the body of toxic substances, diet, and medicinals (10). Subsequent lectures introduced the student to "the history of chemistry, heat, evaporation, mixtures, solution, decomposition, chemical attraction, and apparatus." The main body of the course is divided into seven units: "salts, earths, inflammables, metals, waters, vegetables, and animal substances." Under the heading "animal substances," which touches medicine most closely, Rush lectured on "Solids (hones, skin, membranes), and Fluids (blood, gastric, sinovial (sic) juices, saliva, tears, sweat, insensible perspiration, urine, mucus, bile, wax, fatt (sic), marrow, milk, semen, nervous eather, faeces" (11). Like his mentor. Josenh Black. Rush eschewed loftv scientific theorizing. His course reveals a Baconian preference for low-level eeneralizations closelv linked to exoerience and observation. Sometimes he does explain a phenomenon in terms of phlogiston but neither that theory or any other is given prominence. Rush was not noted for illustrating his lectures with experimental demonstrations. Neither did he do much research. But he was an enthusiast for chemical learnine and ureed his students to think for themselves accordingto the Lest principles of scientific skepticism. He was in demand as a practicing physician (even though today we cringe a t his all too ready recourse t o bleeding) and he was highly regarded as a Christian layman, a civic leader, and patriot. During the Revolution the Medical College was closed while the British occupied Philadelphia and Rush found himself absorbed in politics (he was a sig-

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1 The first chemistry text written and published in America. 'Son of the Rev. Francis Alison who in 1743 had founded the New London Academy which later moved to New-Ark, Delaware, and eventually became the University of Delaware. . . ,,.. . ,,...

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James Woodhouse (1770-7809). Professor of Chemistry at the Philadelphia Medical College (17951809).

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Journal of Chemical Education

Anatomical Hall of the University of Pennsylvaniawhere Woodhouse taught and had his laboratory. It was located on 5th and Walnut Streets. over the green behind Independence Hall.

ner of the Declaration of Independence) and busy practicine medicine (at Vallev Foree. for instance). He was eviddntly losing touch with chemistry which was undergoing a revolution of its own in France at the hands of 1.avoisier and his colleagues. This was probably a factor in the resignation of Rush from the chair of chemistry in favor of the chair of medicine which had become vacant through the death of John Morgan in 1789 (12). As a professor Rush took a fatherly interest in his students, and while still teaching chemistry he inspired a number of young men to become chemists. Among these were Caspar Wistar, James Hutchinson, James Woodhouse, and John Redman Coxe, all of whom were to follow him in succession as professor of chemistry a t the medical school. Of these James Woodhouse (1770-1809) was the only one who did not eo to Eurone for further studv: vet he became the most infuential anb able chemist of the group. After receiving his Bachelor of Arts degree from the University of Pennsylvania a t age 18, Woodhouse entered the medical school where he attached himself to the influential Benjamin Rush. With lavish praise he dedicated his doctoral thesis "On the Chemical and Medical Properties of the Persimmon Tree," to his mentor who returned the compliment by praising his pupil's "zeal and industry . . . which have led you to valuable discoveries" (13). In 1795 Rush used his formidable influence to secure Woodhoore's appointment 10 the chair of chemistry in the school of medicine which \Voodhouse then occupied for 14 years till his early death a t 39. In contrast to the-outwardly impressive and statesmanlike Rush, Woodhouse was a quaint little man with a florid face, an academic specialist with only one passion: chemistry. T o his students Woodhouse recommended that they take "Miss chemistry as their only mistress, the only object of their devotion and homage" (14). He himself spent virtually all his time in a little laboratory located in Anatomical Hall on 5th Street overlooking the yard behind Independence Hall. One of Woodhouse's students, Charles Caldwell, later reminisced about an exceptionally hot summer during which he had visited the professor's laboratory. The temperature outdoors was between 110 and 115OF. and in the laboratorv. -. working obliviously among red hot furnaces and blazing charcoal. was Woodhouse. collar open. sweat-drenched from head to toe. In answer to how- hecould stand this "perfect pureatorv." the doctor launched on an impromptu lecture on the manner in which perspiration cools the body by carrying off caloric. Caldwell concluded that "alchemy and chemistry have deranged a greater number of intellects than all other branches of science united" (15). Benjamin Silliman, who subsequently distinguished himself a t Yale, also studied under Woodhouse and later said that the professor lacked "the gift of a lucid mind" and fluid diction: that "He appeared, when lecturina, as if not quite at ease, as if a littlifearful that he was nothighly appreciated-as indeed he was not very highly" (16). However, the long-run evaluation of Woodhouse by his colleagues and suhsequent historians is different. All are agreed that he was an exceptionally skillful analyst and experimenter; that he demonstrated the indispensability of the laboratory to university teaching and research; and that he proved the great utility of chemistry, not only to medicine, but to many facets of agriculture and manufacture. Woodhouse did virtually everything that we today expect from a chemistry professor. He corresponded with the leading chemists of America and Europe. He kept abreast with the latest chemical discoveries and theories. He published continuously and significantly. His marvelously concise "The Young Chemist's Pocket Companion" (1797) was the first laboratory manual written in America. He edited and enlarged three European chemical treatises, by Parkin-

Woodhouse did virtually everything that we today expect from a chemistry professor. He corresponded.. . He kept abreast. . . He published.

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son, Parkes, and Chaptal, respectively, which were reprinted in this country. He also took an active part in debating the hottest chemical issue of his time: the phlogiston hypothesis versus the oxidation theory. In the early 1790's most American chemists, including Woodhouse, had been won over to Lavoisier's explanation of hurning and to the Frenchman's definition of an element as a chemically irreducible substance. Upon this definition tlie French had also launched a sweeping reform of chemical nomenclature. However, doubt about the rightness of the French school was rekindled in 1794 when Josenh Priestley immigrated to Pennsylvania (17). Since Benjamin Franklin had died four vears earlier. Priestlev became the only scientist in the united States kith a world-wide reputation. Americans were proud of his wresence. In 1795 h'was offered the chair of chemistry in tke medical school of the University of Pennsylvania but he declined graciously thereby clearing the way for Woodhouse's appointment to that post. Priestlev was the staunchest defender of the phlogis