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Robert Mayer and the Conservation of Energy
By Kenneth L. Caneva PRINCETON UNIVERSITY PRESS
Copyright © 1993 Princeton University Press
All rights reserved.
ISBN: 978-0-691-08758-0
CHAPTER 1
Mayer the Person
1 Mayer's Upbringing and Education
Julius Robert Mayer was born on 25 November 1814 in the city of Heilbronn, a former Reichsstadt situated on the Neckar River in the southwest German kingdom of Württemberg. Heilbronn, a prosperous city and one of the quickest in the state to industrialize during the nineteenth century, saw its population rise from around 7,100 in 1820 to 11,300 in 1840 and 14,300 in 1860; growth in the surrounding district kept pace, and contributed an additional population about equal to that of the central city. Its inhabitants were overwhelmingly Evangelical (i.e., Lutheran), as was Mayer's family. Mayer's father owned an apothecary in which his three sons received early practical chemical experience. The eldest brother, Fritz (born in 1805), first worked as an assistant to his father, then took over the enterprise sometime around 1832 or 1833; the middle brother, Gustav (bom in 1810), worked as an apothecary in the Baden towns of Messkirch and Sinsheim before emigrating to America in 1849. Gustav Rümelin, one of Robert Mayer's lifelong closest friends, reported that Mayer senior devoted his free time to scientific studies and experiments and that the Mayers' house was filled with physical and chemical apparatus and instruments, botanical and mineralogical collections, medicinal plants, and many books, especially travel accounts. He recalled that Mayer performed experiments and exhibited curiosa to his friends, skillfully operating an air pump and various electrical devices. 'Young Mayer was familiar with elementary chemical procedures, could identify the contents of most of his father's apothecary canisters and tell what they were used for, and could name plants according to the Linnaean system.
In several of his autobiographical sketches Mayer told the story of his childhood fascination with machines and his abortive attempt to construct a perpetuum mobile. Although the lasting significance of the experience for Mayer has been called into question, I take Mayer's account seriously and will later argue that the lesson he thereby learned played a crucial role in the development of his theory of force. Mayer recounted his early endeavors in great detail (writing of himself in the third person):
Already as a young boy, chemical and physical experiments and the construction of watermills in his hometown were much more attractive to him than the prescribed study of Latin and Greek, which frequently drew down upon him the dissatisfaction of his teachers.
Is is perhaps appropriate here to recall an in itself unimportant incident which, given the impressionable spirit of youth, made a lasting impression on our investigator. He must have been somewhat more than ten years old. It was a common diversion in the afternoon hours to place small waterwheels in a small brook (the Pfühlbach) which flowed into the Neckar at Heilbronn, and by means of their rotation to move other small objects as well. Now it was on this occasion that our small man hit upon the great idea of constructing a perpetuum mobile. In his mind he fastened to the axle of such a wheel an Archimedes screw, whose operation he knew from Poppe's Physikalischer Jugendfreund, which he had gotten from his father for Christmas. But since when such an endless screw runs over a large cogwheel what is gained in "force" is lost in speed, he accordingly restored this loss easily again by having the large cogwheel engage a small one. Now on the axle of this small cogwheel there is again a screw, which engages a large cogwheel, etc. In this way, by means of such a transference, the boy concluded, so much force must obviously be gained that arbitrarily heavy machines could be driven by a tiny waterwheel. Set straight by other, older people — namely, that by means of the transference [of motion] from a large cogwheel to a small one as much "force" is again lost as one gains in speed — he in turn quickly gave up his project, but through his error at such a young age attained the insight [that mechanical work cannot be created out of nothing].
This disappointment, however, did not keep young Mayer from continuing to be fascinated by the mechanical devices that were becoming increasingly common in the area. Friend Rümelin, who had gone off to the Evangelical school in nearby Schöntal in the fall of 1828 (where Mayer would join him the following spring), recalled that Mayer wrote to him then "that he now spent his free time in the numerous and diverse mills and factories which lay next to each other along the Neckar, studying their mechanism and assisting the people in their work." Mayer apparently continued to be fascinated by machines' ability to do work and by the operators' ability to control their effect by means of relatively small causes. After noting, in a late essay, that people are by nature so constituted that they like to obtain the greatest possible results by expending the least means, he went on to reminisce about his boyhood fascination with machines: "From the years of my youth I still remember very well how on free afternoons I spent many an hour in a sawmill, where by pressing on a lever and withdrawing the sluice gate the mechanism was set in motion."
After attending the Evangelical school in Schöntal for two and a half years and then assisting in his father's apothecary for eight months, Mayer enrolled at the Eberhard-Karls-Universität in Tübingen in May 1832 to study medicine. With the exception of a physics course during his first semester, his five-year program of study was devoted entirely to his medical training. The medical faculty at the time seems to have consisted largely of relatively unprogressive and unphilosophical teachers of a practically oriented medicine, and the claim that the idealistic philosophy of Hegel "wholly determined" the intellectual climate at Tübingen while Mayer was there is without foundation. The dean of the faculty and chancellor of the university, Johann Heinrich Ferdinand Autenrieth, had a solid reputation as a defender of an empirical approach to medicine allied with anatomy and physiology and thus as an opponent of the various currents of Romantic medicine that were, in the early decades of the century, gaming widespread allegiance at many other German universities." Contemporary reviewers of Autenrieth's Handbook of Empirical Human Physiology repeatedly emphasized his devotion to empirical observation, in contrast to the speculations of those influenced by Naturphilosophíe. Of Mayer's teachers, I find only one to have shown any significant attachment to one of the then-competing major philosophical movements — Ferdinand Gottlob Gmelin, who in his General Pathology of the Human Body (a book Mayer owned) explicitly embraced Kant's notion of purposefulness.
Wilhelm Griesinger, a close friend of Mayer's who studied medicine at Tübingen from 1834 to 1837, praised only one of his teachers as good, the anatomist (and praeses of Mayer's dissertation) Wilhelm Ludwig Rapp, of whom we are told by an anonymous contemporary: "In accordance with his maxim only to believe what he can convince himself of through personal observation, he must direct his efforts to such fields as offer him no obstacle in this connection, and he thus accords almost no room to speculation. He does not directly admit his generally assumed attachment to materialism; however, in his lectures he concedes the highest significance to matter and (in particular) to the blood." Another member of Mayer's circle of medical-student friends, Wilhelm Roser, recalled that "the physiologist W. Rapp taught the propulsive force of the blood and the pathologist F. Gmelin the polarization of the vital force. The other pathologist, Autenrieth (junior), taught according to his own system, in which the scabious and miliary sequelae, etc., played a prominent role." Unstimulated by the instruction offered by the medical faculty, Roser and his cohort read Johannes Müller, François Magendie, and the four unauthorized volumes of Johann Lucas Schönlein's clinical lectures. But good books were hard to identify and obtain. The only member of the Tübingen medical faculty to inspire members of the younger generation was Albert Friedrich Schill, Privatdozent from 1835 until his untimely death from typhus in 1839. Schill was a major force in introducing his enthusiastic students to the new French and English clinical medicine, not least by lending students books from his own library. These students did not, however, include Mayer.
In addition to Griesinger and Roser, Mayer was close to one other reformminded and dynamic young medical student, Carl August Wunderlich. Griesinger, Roser, and Wunderlich, who were to become three of the most active voices in the reform of German medicine after 1840, had attended the Stuttgart Gymnasium together and actively shared an interest in natural history, botany, and chemistry. Wunderlich and Griesinger, like Roser, turned to the then brandnew text of Johannes Müller to make up for the deficiencies of the classroom, in which antiquated lore was dictated from old lecture notes.
The quality of Mayer's association with these young men is difficult to determine. Griesinger, Wunderlich, and Mayer were among the cofounders in 1836 of the forbidden student corps Guestphalia, having all previously been members of the corps Giovania. Yet there is no evidence that Mayer shared their disenchantment with the education being offered or their enthusiasm for Schill, and neither Wunderlich's necrologue on Griesinger nor Roser's and Heubner's on Wunderlich nor any other reminiscences of his three medical-student friends mention Mayer as having shared their reformist dynamism. His self-professed conception of medicine reinforces this impression:
With regard to the principles which guided and guide me at the sickbed, I belong to those who understand medicine, the ars medendi, as an art and not as a science. Here one must not follow the principles of some logically thought-out system, but each individual case is to be apprehended by itself and treated according to the rules of an eclectic empiricism, whereby the [doctrine of] "ex juvantibus et nocentibus" is decisive [i.e., according to whether the treatment helps or harms]. ... As my esteemed teacher, the ingenious [geistvoll] chancellor Autenrieth in Tübingen, nicely put it in his introduction to nosology, the system is like a tangent drawn to a circle, to nature; in order not to distance itself too far from the circle, the tangent must often be broken, and this inconsequentiality in the world of our thoughts is the necessary consequence of our insufficient knowledge of the objective world; otherwise the rigid system becomes a Procrustean bed.
Autenrieth was the only teacher of whom Mayer ever spoke highly, calling him geistreich in another recounting of his comparison of an explanatory system "with a tangent drawn to the great circle of truth." It is possible, too, that Mayer might have been alienated by the materialistic and reductionist approach to medicine to which his friends subscribed.
In February 1837 Mayer and a number of Corpsbrüder were arrested for wearing the colors of a forbidden organization. Mayer and Griesinger were expelled for a year, and Wunderlich received three weeks' incarceration. During the summer and fall of 1837 Mayer traveled to Switzerland and visited clinics in Munich and Vienna, though without notable effect. Rümelin could not recall any significant details of those visits, and Diepgen's later investigations failed to turn up any traces of Mayer's presence in either city. Nor are there any detectable traces of his later attendance at medical lectures and demonstrations in Munich in November and December 1838.
During his enforced absence from Tübingen, however, Mayer apparently solidified his desire to travel to the East Indies, a region of the world that had fascinated him since childhood. Having passed his medical exams and completed his dissertation (on santonin, an anthelmintic) in 1838, he traveled to Amsterdam in June 1839 to take the examination to become a ship's doctor in Dutch service. Having been admitted to that service late in September, Mayer spent the next four and a half months in Paris. There he hung out with his former university friends Griesinger, Wunderlich, and Roser, and made the acquaintance of Carl Baur, a student of mathematics and mechanics who lived with Mayer and Roser in the Latin Quarter. (Baur would later become an administrator and teacher at a number of Württemburg secondary schools before obtaining a professorship in mathematics and practical geometry at the Polytechnic School in Stuttgart.) Drawing apparently from information supplied to him by Baur, Weyrauch recorded that Mayer principally visited demonstrations at bedside and in the operating room, without showing any particular interest in purely scientific matters.
2 Mayer's Voyage to the Dutch East Indies
On 23 February 1840 Mayer left Rotterdam aboard the ship Java to sail to the Dutch East Indies. For most of the voyage his duties as ship's doctor took up little of his time, and he settled into a routine that included periods of "scientific activity" once or twice a day. Several letters written after the voyage allow a sharper specification of what those scientific activites were. In recounting the circumstances surrounding his discovery, he portrayed himself as "taking as my starting point physiological and pathological investigations" and as "occupying myself ... almost exclusively with the study of physiology"; he said he made his discovery "through the unremitting study of a specialized area of physiology," from "having occupied myself zealously and unremittingly with the physiology of the blood." This study and Mayer's reflections thereon set the stage for his observation of the lighter-than-expected color of the venous blood of Europeans recently arrived in the tropics. Mayer's first recorded account of this episode dates from 1845: "During a 100-day sea voyage there had occurred no appreciable incidence of disease among the 28-man crew; however, a few days after our arrival at the Batavian roads there spread in epidemic fashion an acute (catarrhal-inflammatory) affection of the lungs. In the copious bloodlettings I performed, the blood let from the vein in the arm had an uncommon redness, so that from the color I could believe I had struck an artery," From the entries in Mayer's medical log it appears that those venesections took place on or shortly after 20 June 1840. Subsequent accounts confirm the importance of these observations in setting off Mayer's chain of reasoning.
There is, unfortunately, little evidence as to what books Mayer had with him. It would seem safe to assume he took along Johannes Mtiller's then new and universally acclaimed Handbook of Human Physiology, of which he owned the second edition of the first volume (1835) and the first (and only) edition of the second (1837–40). The third part of the second volume, although dated 1840, came out at the end of 1839, hence Mayer could have had the complete work on board. Also in his library and reasonable candidates for inclusion among the books he had with him are Autenrieth's Handbook of Empirical Human Physiology (1801–2) and Burdach's Anthropology for the Educated Public (1837), which, despite its title, covered roughly the same ground as contemporary physiology texts. He might have had one of the several French or German editions of Magendie's Elementary Sketch of Physiology, the third edition of which was translated into German by one of Mayer's professors and published in Tübingen in 1834–36. Among other major contemporary works with which he was surely familiar one should add the first volume of Friedrich Tiedemann's Human Physiology (1830) and Berzelius's Textbook of Chemistry, most of the second edition of which was in his library. Mayer cited the fourth edition of the first volume of Geiger's Handbook of Pharmacy (1833) in his 1838 dissertation and undoubtedly owned a copy that might have accompanied him to Java. On the basis of evidence to be discussed in chapter 4, one can conclude that Mayer must have had at least one physics text with him, probably Jacob Friedrich Fries's Textbook of Physics (1826). Given the book's title and its discussion of problems of animal heat and respiration, it is tempting to imagine Mayer having tucked away a copy of Humphry Davy's Consolations in Travel — German editions of which appreared in 1833 and 1839 — but no evidence supports such an inference.
(Continues...)
Excerpted from Robert Mayer and the Conservation of Energy by Kenneth L. Caneva. Copyright © 1993 Princeton University Press. Excerpted by permission of PRINCETON UNIVERSITY PRESS.
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