The lessened locus of feelings: A transformation in French physiology in the early nineteenth...

The Lessened Locus of Feelings: A Transforma- tion in French Physiology in the Early Nineteenth Century

MICHAEL GROSS

School of Natural Science Hampshire College Amherst, Massachusetts

Physiology in France during the first quarter of the nineteenth century has been discussed in terms of methodology - its novel or increased reliance on vivisectional experiments; reductionism - its growing rapprochement with the physical sciences; philosophy - its in- corporation of assumptions from the philosophical system of ideology; and disciplinary structure - the development and ascendancy of a uniquely physiological conept of function, free of the limits of an earlier dependency on anatomical deduction. ’ Here, the point of departure is

1. William Coleman cites both vivisectional and physicochemical approaches in his Biology in the Nineteenth Century (New York: John Wiley, 1971), observing that a general conception of life and organism “commonly determined or, at the very least, offered essential premises for the determination” of a physiologist’s choice of method. More specifically, F. L. Holmes describes the physicochemical approach in “Elementary Analysis and the Origins of Physiological Chemistry,” Isis, 54 (1963), 50-81. Relatedly, Everett Mendelsohn argues that the role of physical and chemical theories in physiology was more important than vitalism or mechanism in characterizing physiological research, in “Physical Models and Physiological Concepts: Explanation in Nineteenth Century Biology,” Brit. J. Hist. Sci., 2 (1965), 201-219. Karl Rothschuh’s pioneering Geschichte der physio- logie (Berlin: Springer, 1953) and, more specifically, J. M. D. Olmsted’s Francois Magendie (New York: &humans, 1944) and M. D. Grmek’s “Franqois Magendie,” Dictionary of Scientific Biography (New York: Charles Scribner’s Sons, 1974), IX, 6-11, emphasize the use of vivisectional methods. V. S. Kruta puts J. J. C. Legallois first in the series of French experimentalists but likewise sees in that method a crucial transition from observation and speculation, in Dictionary of Scientific Biography, VIII (1973) 132-135.

Joseph Schiller likewise emphasizes experiment, but in relationship with a uniquely physiological concept of function in “Physiology’s Struggle for Inde- pendence,” Hist. Sci. 7 (1968), 64-87, and Claude Bernard et les problkmes scien- tifiques de son temps (Paris: Editions du CBdre, 1967). Denying that methodology was the source of novelty, W. R. Albury also emphasizes the development of a uniquely physiological concept of function which in turn required an experimental approach, in “Physiological Explanation in Magendie’s Manifesto of 1809,” Bull. Hist. Med. 48 (1974), 90-99, and “Experiment and Explanation in the Physiology of Bichat and Magendie,” Studies in History of Biology (Baltimore: Johns Hopkins University Press, 1977), I, 47-131. While Albury supports the conclusion stated here on the importance of Georges Cuvier in the reformulation

Journal of theHistory ofBiology, vol. 12, no. 2 (Fall 1979), pp. 231-271. 0022-5010/79/0122-0231 $04.10 Copyright 0 1979 by D. Reidel Publishing Co., Dordrecht, Holland, and Boston, U.S.A

MICHAEL GROSS

more narrowly internal, for the general interpretation depends upon the identification of a change in the content of physiological research on a network of issues related to the concept of feeling or sensibility. Such a change has, in turn, implications for the scientific treatment of the relationship between mind and body. This study interprets these inter- related transformations in physiological thought in terms of interactions not primarily between biology and the physical sciences but between distinct subdisciplines of biology. However, the change described here did not mean a renunciation of anatomy, for the nineteenth-century physiologists discussed here drew inspiration from the attitudes of comparative anatomists and zoologists. And, instead of depending upon functional thinking freed of anatomical considerations, the conceptual shift reordered earlier relationships between functions and structures. Such an analysis assumes that changes in the pattern of association between functions and structures diagnose significant transformations of physiological theory and occasion important changes in research objectives.

This paper recounts a change in the way physiologists treated feelings - including both sensations and motions - and emotions. The anatomical structures of an organism believed to be capable of feeling and moving became more sharply delimited anatomically. Major French physiological theorists in the first quarter of the nineteenth century systematically promoted the view that feelings and motions pertain to the neuromuscular system and specific sense organs. In contrast, toward the latter part of the eighteenth century physiologists had thought that every part of a living body which is at all alive also feels, to some extent. For instance, ligaments and tendons sometimes become hotly inflamed and painful, though usually they feel more calmly and subtly. When the stomach feels it has churned its contents sufficiently, it pushes them along into the gut. All the fibers - of muscle, artery, membrane, paren- chymatous organs like the liver, and so on - are aquiver and jostling, transforming the surrounding liquids, feeling them for proper “tastes” and consistency and sucking up only those which are agreeable and taste right. Thereby internal chemical transformations - secretion,

of physiological thought, a remark by Georges Canguilhem suggests difficulties with the notion that functional thinking was new to physiological reasoning: he notes that Harvey, Haller, and Lavoisier all introduced considerations other than those based on anatomical deduction. See his “La constitution de la physiologic comme science,” in Etudes d’histoire et de philosophic des sciences (Paris, 1968), pp. 226-213. The expectation that a concern with function per se probably underlies every major change in physiological theory underlies this study.

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nutrition, assimilation, absorption - occur. Emotions were treated also as feelings centered in the visceral organs, while ideas were in the brain.

The group of early nineteenth-century researchers discussed below disagreed with the eighteenth-century concept that all parts of the body are alive with sensation and motion. From early on in their careers, during the period 18051825, J. J. C. Legallois, Georges Cuvier, Francois Magendie, and Pierre Flourens articulated the opposing view that feelings were felt not peripherally but in the brain only, borne to it by fibers of the nervous system. Emotions, correspondingly, were mental events: like all sensations their point of reference was the brain, not the visceral organs. For the early nineteenth-century physiological theorists, emotions were a kind of idea, not a passion derived from the condition of such organs as heart, stomach, or lungs. In addition, they denied that feelings had anything to do with changes in the fluids - their absorption, secretion, or assimilation by the organs - or, consequently, with nutrition. Processes such as assimilation and absorption, which had been treated, rather cursorily, as manifestations of sensibility in the late eighteenth-century, were attributed in the early nineteenth century to physicochemical agents of as yet unknown nature. And the analysis of these forces was coming to be seen as the crucial problem of physiology. Throughout the following discussion, the term “metabolism” is employed, albeit anachronistically, even for late eighteenth-century treatments of internal chemical transformations, processes which then had been understood as results of feelings but which were, in the early nineteenth century, reinterpreted as the locus of sensibility receded.

This paper begins by documenting the transformation summarized above, describing the eighteenth-century theories and the early nineteenth-century experimental and theoretical results arrayed against them. It then names and attempts to assess some factors responsible for the change: institutional contributions coming through the influence of the French Academic des Sciences, and theoretical influences stem- ming largely from a zoological tradition which held assumptions different from those of the prevailing medically based physiology.

DIFFUSED SENSIBILITY AND CONTRACTILITY IN THE LATE EIGHTEENTH CENTURY

In the mid-eighteenth century, Albrecht von Haller had published experiments which established that only nerves are “sensible” or able, when disturbed, to elicit expressions of pain, while only muscles are “irritable,” or capable of self-motion. As he reported them, the experiments

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clearly and exhaustively eliminated these properties from all other parts of animals, including ligaments, tendons, membranes, secretory ducts, and blood vessels.* Yet in the succeeding half century, despite whatever differences separated them, a series of important French physiological theorists adopted and propagated a contrasting view of sensibility and contractility.

These theorists shared two main concepts in their interpretation of these properties. They thought that a host of nonnervous and nonmuscular tissues could exhibit sensibility and contractility. And, in relation to this, they thought that sensibility and contractility not only had to do with feeling and moving but also presided over a group of metabolic processes including selective absorption, nutritive assimilation, and secretion. In other words, sensibility and contractility were seen rather diffusely, both functionally and anatomically. These opin- ions emerged in the writings of a series of popular and influential medical thinkers publishing in France between 1750 and 1810: the Montpellier physicians Theophile Bordeu, Paul Barthez, and C.-L. Dumas; authors of major articles on medicine for the Encyclopidie; and the Parisian physicians Pierre J. G. Cabanis, Xavier Bichat, and A. Richerand.

Both Bichat and Richerand, for example, emphasized the contractility and sensibility of various sorts of membrances, including those constitutive of the internal visceral organs.4 They believed that in an

2. Albrecht von Haller, “On the Sensible and Irritable Parts of Animals” (1753),Bull. Hist. Med., 4 (1936), 659.

3. Many of these themes are explicated more fully, although for the different purpose of assessing Bichat’s debt to Montepellier thought and to R. Whytt, in Elizabeth Ha&h’s “The Roots of the Vitalism of Xavier Bichat,” Bull. Hisf. Med., 49 (1975), 72-86, and her “Vitalism, the Soul, and Sensibility: The Physiology of Theophile Bordeu,” J. Hist. Med., 31 (1976), 3041. Also Albury summarizes the emphasis - in the theories of Barthez, Chaussier, Dumas, and Richerand - on the principles of sensibility and contractility, illustrating that these physiologists shared Bichat’s views, in “Experiment and Explanation,” pp. 77-80.

4. Bichat endowed every organ, muscular or not, with some species of sensibility and contractility. The internal viscera, for instance, exhibited wavelike, macroscopic motions of “organic contractility,” which he regarded as an effect of “organic sensibility” (Physiological Researches on Life and Death, with notes on the text by F. Magendie, trans. F. Gold [Boston: Richardson and Lord, 18271, p. 104). Richerand cited the observed contractions and undulations in a fluid- filled membrane in the body of a surgical patient as evidence of the existence of contractility in nonmuscular fibers. The observation “serves to prove, much better than all experiments made on living animals . what we ought to think of the pretensions of Haller and his followers on the insensibility and non-irritablity of

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organism seats of sensation were spread among the individual organs and tissues, and not restricted solely to the central nervous system or the brain. Bordeu observed that “the living body has come to be viewed as an assemblage of diverse organs, viscera and others, each of which enjoys a particular feeling [sentiment] and movement, a decided disposition for such a feeling and such a movement.” s Bichat cited examples in which the sensibility responsible for the functioning of the visceral organs was seated in the organs themselves, not in any central nervous structure (as is the case for sensations respecting the external world): “The stomach is sensible to the presence of aliments, the heart to the stimulus of the blood, the excretory tube to the contact of this fluid which is peculiar to it; but the tern of this sensibility is the organ itself.“6 This sensibility on the macroscopic level - which Bichat denominated “organic sensibility” - explained digestive and, to some extent, nutritive processes by way of its effect on the state of “organic contractility” of

serous membranes and other organs of analogous structure” (The Elements of Physiology, trans. R. Kerrison [Philadelphia: Hopkins & Earle, 18081, p. 7). Similarly, Barthez spoke of muscular motion in nonmuscular organs such as the Fallopian tubes in Nouveaux elemens de la science de l’homme (Montpellier: Martel, 1778), pp. 64-65. Cabanis anatomically conflated nerve and muscle fibers by describing the latter as a combination of nervous pulp and cellular tissues (Oeuvres completes [Paris: Bossange Freres, 18241, III, 66-67). Every part which acted - which meant every living fiber in the organism - did so because innerva- tion made it sensible and contractile.

5. Theophile Bordeu, Ueuvres (Paris: Caille et Ravier, 1818), II, 800-801. 6. Bichat, Physiological Researches, p. 82. Likewise, Cabanis thought that the

phenomena of the animal economy could be imputed to the same cause as voll- tional movement - sensibility - because sensibility is exercised in organisms lacking nerves and brain, such as polyps, and because the parts which Haller had declared insensible “can in certain ill states become susceptible of lively pains; from which it seems clearly to result that, in the ordinary state, their sensibility, suited to the nature of their functions, is only weaker” (Ueuvres, III, 113; cf. also p. 122.) Cabanis’s comments suggest why physicians found reasonable such explanations involving sensibility: active functioning of a part could be compared to a mild inflammation.

Richerand adopted a view like the one Cabanis had expressed, relying on local sensibility to explain, for instance, why the pyloric valve does not let food pass until the fibers of that valve sense that it has been “sufficiently elaborated.” They know. (Eiements, p. 60.)

Bordeu, speaking of digestion but manifestly meaning assimilation and growth, observed that “digestion reduces to a true extraction, to a true choice, and to a very real distinction of good from bad; and no doubt sensibility presides over this function” (Ueuvres, p. 940).

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the viscera, which arrested some substances while allowing others to pass on.

Likewise, metabolic processes were explained - on the microscopic level - by the “organic sensibility” of the fibers affecting their state of “insensible organic contractility.” While Bichat’s predecessors lacked his specific term for the latter, they used the concept: an imperceptible trembling or quivering of the fibers which acts on substances in adjacent fluids.7 Bichat declared that “insensible organic contractility” was “the means by which excreting tubes react on their respective fluids . . . wherever the fluids are disseminated in small quantities or are very much divided.“* But neither he nor his predecessors went into much further detail on the fine points of metabolic transformations: their discussions offered explanations really only in principle; short on detail, they occupied little space in late eighteenth- and early nineteenth- century treatments of physiology.9

The clearest account of the role of sensibility in metabolic processes concerned its action not in the metamorphosis of substances but rather in their discrimination and separation from one another: “It

7. For instance, Barthez, in trying to explain secretion and assimilation, wrote (Nouveau elemens, pp. 104-105), “it is necessary to relate to the immediate action of the vital principle on these fluids the intestine movements which cause the formation of each humor, and which fix the duration of specific fermenta- tion” (also cf. pp. 43, 107).

8. Bichat, Physiological Researches, pp. 107-l 10. 9. Bichat figuratively threw up his hands: “Why do these organs establish

relations so different between the organs and the substances that are foreign to them? Let us stop here; let us be contented with proving this fact by a great number of examples without trying to discover the cause. We could offer nothing but conjectures upon this subject.” The “great number” of examples constituted a survey of the names of the secretions produced by the different tissues; there were no further comments on the mechanism involved in their formation. See his Anatomie g&Crate (Paris: Brosson et J. S. ChaudC, 1822), I, 85.

While the French theorists may have differed with Haller in their understanding of sensibility and contractility and of the nature of metabolic processes (which Haller explained with physicochemical models), they, like Halter, treated such processes summarily, and in passing. Halter had discussed metabolic processes only in interstices of his textbook in the essays “On Death,” “On Diges- tion” and “On the Cellular Tissue.” In Cabanis’s work, the relevant passages appeared in memoirs entitled “Intlucnce of the Ages on Ideas and on Moral Affections” and “First Determinations of Animal Sensibility.” Barthez included two or three relevant paragraphs in his 200-page treatise Nouveaux elemens de la science de I’homme (1788). Richerand’s pertinent comments occur only on 3 out of some 300 pages of text.

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is by the effect of a sensibility inherent in secretory and excretory organs, by a sort of touch [fact], that they distinguish which humour they should seize . . . The vitality, the sensitive touch of secretory organs, is announced in a manner which cannot be misunderstood”.1o Here C.-L. Dumas was echoing, among others, Bichat’s description of the consequences of the organic sensibility of an organ, rr “which places it in relation to this or that substance and not to another, and which makes it appropriate it to itself, is penetrated by it, and allows it to encounter its vessels on all sides while it draws back and contracts to prevent what is foreign from being introduced into its texture.“‘? In this description by Bichat, the actions of organic sensibility cannot be dissociated from its immediate consequences for the state of organic contractility.

Yet while Bichat denominated five categories - organic sensibility, sensible and insensible organic contractility, and animal sensibility and contractility - he, like his predecessors and colleagues, in fact conflated them as manifestations of one general phenomenon, sensibility. His distinct categories of sensibility and contractility differed not qualitatively but only quantitatively, in level of intensity. Regarding sensible and insensible organic contractility, “the one is but the extreme of the other; they are both connected by invisible gradations.” l3 Similarly, in animal contractility, the muscles “possess the maximum of organic contractility, but every living organ acts as they do through in a manner less apparent, upon the excitant when artificially applied, or on the fluid which , in the natural way, is carried to it for the purpose of supplying the matter of secretion, nutrition, exhalation, or absorption.“r4 Organic graded into animal (i.e., the consciously perceptible): inflammation, by exalting the organic sensibility of a part, transforms the organic into the animal sensibility.“‘5 Organic sensibility and organic

10. C. L. Dumas, Principles de physiologic (Paris: Imprimiere du Crapelet, 1800-1803) III, 587-588.

11. And, not so incidentally, he was also employing such explanations to deny Haller’s physicochemical models for such metabolic processes (ibid.): “Their functions depend neither upon the configuration of vessels which changes at every moment nor on any compromise action of surrounding parts, nor on any physical, mechanical, or chemical causes which have given rise to hypotheses of all sorts on the mechanism of secretions.”

12. Bichat, Anatomie, p. 82. 13. Bichat, PhysiologicalResearches, p. 111. 14. Ibid., p. 116. 15. Ibid., p. 86.

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contractility are “never separated,” for a wave of organic contractility is the immediate and inevitable response to a stimulus acting upon organic sensibility, and they both occur in the same fiber.16 Indeed, the only distinction which remained was that which deprived the cerebrospinal nervous system of any role in the organic actions of such organs as the heart or intestines,” and which denied the nerves any role in insensible organic contractility.‘*

.

Even Bichat’s doctrine of emotions reflected both the distinction between animal and organic and the breaching of the gap. Passions were of the body - their seat was in the visceral organs and their effect, primarily, was on organic systems of respiration, circulation, and nutrition. Volitions were of the mind - based on a process of judgment seated in the brain, which acts through voluntary muscles. However, the voluntary muscles, under the impulsion of such powerful emotions as grief or rage, become involuntarfy spasmodic or paroxysmal while “the brain is passive”;19 thus “the passions withdraw from the empire of the will those motions which by nature are voluntary.“20 For instance, Bichat relates, the knitted brows and pallor consequent upon receipt of bad news “are sympathetic phenomena produced by the abdominal viscera which have been affected by the passions, and which in consequence belong to the organic life.” This state persists until reason supervenes, “the man is capable of putting a constraint upon himself, his countenance clears up, his colour returns.“21

While Bichat followed his predecessors in identifying separate seats of reason and emotion and thus dichotomizing mind and body, his later critics also maintained such a separation, though on a different level. For, as the following sections show, they interpreted passions and emotions as species of ideas with the point of reference even of “internal sensations” being the brain rather than the body.

THE LOCALIZATION OF SENSIBILITY AND CONTRACTILITY DURING THE EARLY NINETEENTH CENTURY

A cadre of early nineteenth-century French biologists - J. J. C.

16. Ibid., pp. 127-129. 17. Ibid., p. 120. 18. Bichat bluntly stated, “life entails no necessary association with the brain,

at least not directly,” and argued the position in detail (ibid., pp. 318-334, esp. p. 327).

19. Ibid., p. 65. 20. Ibid., p. 67. 21. Ibid., p. 68.

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Legallois, Georges Cuvier, Francois Magendie, Pierre Flourens - took the highly diffuse concepts of sensibility and contractility of Bichat and his predecessors and turned them upside down. They reformulated the interpretation that sensibility and contractility differed only quantitatively into a qualitative distinction, and embodied that distinction in a highly specific assignment of those phenomena to particular parts of the neuromuscular system. In fact, the only distinction they blurred was precisely the one that Bichat sought to maintain: that which denied the cerebrospinal system a role in the actions of the viscera. Metabolic processes, which had been given relatively little attention and had been treated as an almost incidental manifestation of organic sensibility and organic contractility, they spotlighted as the central problem of physiology, one which could not be solved by appealing to feelings or motions but which had to do with molecular or macro-molecular structure and physical or quasi-physical forces. In other words, they took a group of phenomena which had been conflated and placed along a continuum of quantitative differences in intensity, and distinguished them qualitatively from one another. Moreover, they took processes which had been situated indiscriminately in every living fiber and segregated some of them in discrete anatomical structures of the neuromuscular system, while newly formulating others as urgent problems in the relationship between physicochemical forces and micro-anatomical structure. (This was no mere return to Hallerian concepts, however, though these workers refer appreciatively to Haller. For the focus here is specifically on the neuromuscular system and the detailed analysis of the properties of its parts, whereas Haller’s objective was to divide the tissues in general into sensible, irritable, and inactive).

Once the concerns of the early nineteenth-century physiologists are seen from this perspective, the objectives of Magendie’s initial research, the emphases of his didactic writing, and the relationship between his concerns and those of his physiological colleagues Legallois and Flourens become apparent. Magendie’s early work, as well as that of Legallois and Flourens, undermines the diffuse interpretation of sensibility and contractility and delimits those properties in areas of the neuromuscular system.

In their experimental studies, Legallois, Magendie, and Flourens employed “positivistic” criteria of sensibility and contractility: these had to be seen to be believed - they had to be established by definite evidence according to explicit criteria. Sensibility meant some overt expression of pain (such as convulsions) or some indication that the

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animal had tasted, seen, heard, etc. Contractility meant visible shortening of a muscle, motion of a limb, etc.

Legallois, like his eighteenth-century predecessors, continued to associate the general conception of life with feeling and movement, but published in 1808 an extensive series of experiments designed to establish that in animals life, feeling, and movement all pertained exclusively to the spinal cord.

Legallois deployed his results to contradict Bichat’s division of the body into “two lives,” animal and organic. Rather, the cerebrospinal, or “animal,” nervous system provides a constant source of power for the activities carried on by the organs of the “organic” system. Further- more, the very linkage between the animal and organic systems via the spinal cord explains such phenomena as a general disorder throughout the animal from pain in the bowels. Such phenomena - which previously would have been seen as the sensible response of nonnervous tissues - now depended on the mediation of the central nervous system.

Legallois showed that separation of a nerve from its connection with the cerebrospinal system deprived the parts it innervated of sensation and motion; that showed, he said, that “the sentient principle does not reside in the part which receives the impression, and likewise that the power of causing motion does not exist in the part which moves.“22 Legallois assumed that contraction necessitated the cooperation of nerve and muscle, which then raised the question of what the spasms of an isolated muscle or tremors of an excised heart are. Those latter phenomena he denominated “irritability,” which he treated (as had Haller) as an attribute of muscle fibers alone, and as qualitatively different from contraction, which presupposed life, i.e., spinal cord activity.23 He proved that metameric segments of the spinal cord, each

22. J. J. C. Legallois, Experiments on the Principle of Life, trans. J. G. Nan- crede and N. C. Nancrede (Philadelphia: M. Thomas, 1813), p. 24.

23. Legallois offered these observations in evidence (Experiments, p. 36): “The phenomena presented by the severed thigh of the frog are what are commonly called the phenomena of irritability. They are constantly observed for a longer or shorter time after death. Those observed in the decapitated frog belong to life and always suppose the existence of the principle that produces the power of feeling and moving. In short, there is such difference between those phenomena of irritability and of contractility-sensibility that we have reason to be surprised that they should have been confounded.” Such a contrast between irritability and contractility solved yet another interpretive problem. Having assumed that life in general “is produced by a certain impression of the arterial blood upon the brain and the spinal marrow” (p. 58), Legallois needed to clarify the observation that destroying a large part of the spinal cord - such as the lumbar region - caused

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of which gives rise to a pair of dorsal and ventral nerve roots, coordinate the sensory and motor activity of the regions to which their nerves are distributed.

Legallois later referred explicitly to the correspondence between his views and those of the zoologist Georges Cuvier on the limitation of sensibility to the nervous system as opposed to its diffusion among tissues in general.24 He contrasted his establishment in the spinal cord of “a variety of centers of sensation entirely distinct” - its metameric segmentation -with the

opinion by which it is supposed that in the natural state, each organ has a center of sensation and a sort of life peculiar to itself. This opinion, rejected by the soundest theories and the best established facts in physiology had acquired much influence in modern times, when Mr. Cuvier declared himself against it; nothing short of the influence of so justly celerated a man could arrest its progress.2s

However, the clearest written records of Cuvier’s views are dated after Legallois’s own publication.

In 1808, reporting to Napoleon in his official capacity as Perpetual Secretary of the Academic des Sciences, Cuvier went beyond mere reportage to criticize that view of the organism which interpreted different functional activities as the result of different degrees or modes of sensibility and contractility of the fibers constitutive of all organs. His Rapport historique sur les pro&s des sciences naturelles depuis

immediate death of the animal although the heart continued to beat. The heart, he explained, was merely manifesting its inherent irritability, but it actually lacked the necessary power - which would be present in contractile pulsations - to impel the blood around the body (pp. 78,110, 146-147). Legallois went to great lengths to persuade himself and his readers that the still-beating heart was no longer propelling blood through the vessels, and struggled to invent experimental criteria and methods for establishing that circulation had ceased in such instances. The implication of that struggle - that the concept itself was faulty - was pointed out by one of Legallois’s few vocal critics, A. W. Philip, in An Experimental inquiry into the Laws of the Vital Functions (London, 1817), Still, Philip only went Legallois one better by assigning life to the brain rather than the spine.

24. He also sustained Cuvier’s opinion that the spinal cord (by distributing an agent through the nerves) restored the ability of muscles to contract (Georges Cuvier, Rapport historique sur les progres des sciences naturelIes depuis 1789 jusqu’a ce jour [ 18081 [Paris: Verdi&e, 18281, pp. 214-215).

25. Legallois, Experiments, p. 11.

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1789 jusquii ce jour insisted that each organ or organ system had a distinct function which was not necessarily to be explained as a form of contractility. Cuvier further argued that sensibility was invariably associated with the central nervous system rather than situated locally in an organ, and that motions were associated with the action of the nervous system on muscle fibers. He criticized the belief that any fibers were independently contractile, emphasizing instead the cooperation of central nervous system, nerve, and muscle,26 and the need for visible motion to establish contraction.

In contrast with earlier theorists who allowed not only insensible contraction but also unperceived sensation, Cuvier insisted that sensibility must be defined only by its positive manifestations: “it is by an abuse of words that one extends this denomination to functions of this system which are not at all accompanied by perceptions.“27 He called “a supposed local sensibility without perception” a “species of con- tradiction and metaphysical obscurity.“28 Furthermore, contraction of a muscle fiber always “certainly depends in part on the nerve, without depending for that [contraction] on sensibility.“29 To conflate sensibility and irritability as had Bichat and Cabanis “seems to abolish all positive physiology,” 3o for it posits a phenomenon which cannot be observed experimentally. To distinguish them, by contrast, allows one to identify sensation with will and consciousness, and to relocate all sensation in the cerebrospinal system only.

Magendie expressed very similar views the following year, 1809, in a brief but pungent essay modestly entitled “Quelques idltes gCnCrales sur

26. “It is not at all by itself alone that the fiber is contracted,” he wrote, “but by the influence of nervous fibers which are always united to it. The change which contraction produces cannot occur without the cooperation of two substances; and it is still further necessary that it be occasioned each time by an external cause, by a stimulant. The will is one of these stimulants which has the particular character that its conductor is the nerve, and that it is the brain from which it comes, at least in animals of a superior order.” (Rapport historique, p. 213). In the absence of nervous action on muscle, he concurred with Legallois that the muscle independently exhibited irritability: the will “excites irritability in the manner of external agents, and without constituting it; for in apoplectic paralytics, irritability is conserved without the will having any control.” This comment would contradict that previous statement unless Cuvier assumed, with Legallois, that irritable contraction is qualitatively different from genuine contraction elicited by nervous stimulation.

27. Ibid., p. 214. 28. Ibid. 29. Ibid. 30. Ibid., p. 218.

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les phBnom8nes particuliers aux corps vivans.“31 In attempts to explain nutrition using Bichat’s “insensible organic contractility,” for instance, “the physiologists seem to forget”32 that such a phenomenon is “mere supposition . . . they speak of these properties as if they really existed and as if they were established and verified by observation . . . Whatever explanation may be given . . _ , nothing in it is founded on observation.” 33 As for “involuntary, sensible organic contractility,“34 Magen- die considered it “nothing other than the action of the organs in which this property is supposed to exist.” 35 And “the terms organic sensibility and fibrillar contractility designate no appreciable phenomena, but only pure suppositions, simple manners of conceiving.” 36 Magendie also criticized Bichat’s belief that animal sensibility and animal contractility were properties of isolated fibers themselves, and joined Cuvier in insisting that “there can be animal sensibility only insofar as there exist, in the same being, a sense-organ, a nerve, and a brain”37 which act in concert; likewise, animal contractility “does not reside in the muscle; for if the brain is compressed, no contraction; if the nerve is tied or cut, no contraction.“38 Thus, before he published a single piece of experimental research, Magendie had announced what its general significance would be: to reverse the diffusion of sensibility and contractility throughout the organism by localizing those properties in the neuromuscular system.

The argument of Magendie’s first experimental study in 1809, on the action of Javanese arrowhead poision, supported Legallois’s emphasis on the central nervous system, as others publicly noted.39 With his collaborator Delille, Magendie showed that the poison acted as a convulsant by way of the spinal cord (by showing that so long as the spinal cord is destroyed, and whether or not the cord is severed from the brain, the drug produces none of its convulsive effects on the

31. Franqois Magendie, “Quelques id&es g8nkrales sur les ph&nom&nes particuliers aux corps vivants,” Bull. Sci. Med. Sot. MPd. d’Emulation, 4 (1809), 151- 166. Texts cited refer to W. R. Albury’s translation, appended to his “Bichat and Magendie,” pp. 109-l 15.

32. Ibid., p. 109. 33. Ibid. 34. Ibid, 113. p. 35. Ibid. 36. Ibid., 115. p. 37. Ibid., 114. p. 38. Ibid. 39. See note 80, below.

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muscles).40 Concerned next with the question of how the drug could have acted so quickly, Magendie and Delille showed that it was absorbed not by the supposedly sensible mouths at the pores of lymphatic vessels41 but into the venous system. 42 They argued further that since the physical process of imbibition could explain such absorption there was no need to invoke a vital process effected by local sensibility and organic contractility. For the same objective, the denial of local sensibility, Magendie later turned to other physical phenomena - diffusion and capillary attraction - to account for absorption, and encouraged Poiseuille’s study of hydraulic models of the circulatory system.43

Magendie continued to use drugs to attack local sensibility, employing emetine in 1 813.44 Using that plant derivative to study vomiting, he refuted explanations founded on local sensibility or organic contractility in the stomach. Bichat had attributed vomiting to a direct irritation of the stomach: the sensibility of its walls responded to the irritant by con- tracting more violently in an effort to expel it.45 Magendie established,

40. Franqois Magendie, “Examen de l’action de quelques vegetaux sur la moelle epiniere,” Bull. Sot. Philotnut., 1 (1809), 368.

41. Olmsted, Mugendie, p. 100. See also M. D. Grmek, “FranGois Magendie,” Dicfionary of Scientific Biogmphy, IX (1974), 6-l 1, and M. P. Earles, “Earlier Theories on the Mode of Action of Drugs and Poisons,” Ann. Sci., 17 (1961), 97-l 10. The AcadCmie report by Pine1 et al., “Rapport du memoire de M. Magen- die sur les organes d’absorption dans les mammiferes,” Acud. Sci. Proc. Verb., 5 (1813), 142-146, suggests that Vicq d’Azyr, a physician with important research interests in comparative anatomy, had thought veins may absorb.

42. Olmsted’s biography of Magendie makes no mention of this second important point upon which he and Delille based their supposition.

43. Questioning Bichat’s claim that vessels and inert tubes shared no analogy because the former are sensible, Magendie in 1822 predicted (Bichat, Physio- logical Researches, p. 101n): “A great adv ce will unquestionably be made in physiology, when we shall arrive at a kno 2 ledge of the course of a fluid in a system of canals, which have the same physical conditions as the system of arterial and venous vessels.” Between 1828 and 1830, Magendie published a series of papers by PoisetriBe: “Recherches sur la force du coeur aortique,” Magendie, J. Physiol., 8 (1828), 272-306, and 9 (1829), 341-358; “Recherches sur l’action des arteres dans la circulation arterielle,” 9 (1829), 44-59; “Recherches sur les causes du mouvement du sang dans les veines,” 10 (1830), 277-295. Among others, Poiseuille published two major further papers on capillary circulation in the Memoires des Snvuns f?trang&es of the AcadCmie (7 [ 18411, 10.5175), and the Comptes rendus (16 [1843], 60-72).

44. Francois Magendie, De l’influence de l’kmktique sur I’homme er sur les animaux (Paris: Crochard, 1813).

45. Bichat, Physiological Researches, p. 118, locates the cause of vomiting in the fibers of the stomach itself, which “often assume such a susceptibility of contraction that the slightest contact produces the most violent motions in them.”

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by analogy with his prior pharmacologic studies, that the effects of emetine were also mediated by the circulatory and cerebrospinal system. Thus vomiting was not a result of increased gastric sensibility and contractility from the drug irritating the stomach’s walls; rather, Magendie claimed (wrongly6) that the stomach was completely relaxed during vomiting, and instead that nervous stimulation of the diaphragm muscles caused their contraction.

Another result of the same year, also concerning the digestive system, further weakened Bichat’s distinction between animal and organic systems and gave additional support to the localization in the cerebrospinal system of control over visceral as well as “animal” functions. Bichat had included the esophagus among the organs of the organic system because it was involved in digestion. Magendie established that it belonged to both systems: the upper half of the esophagus contracted like voluntary muscle (i.e., suddenly, following nervous excitation, rather than rhythmically) and was innervated by the cerebrospinal system, while the lower portion carried on peristaltic or rhythmic movements typical of organs of the “organic” system.47

Magendie’s name has survived primarily through eponymy because he was codiscoverer of the “Bell-Magendie law”: that the dorsal roots of the spinal cord are primarily associated with sensibility and the ventral roots with motility. But in the persistent discussion of whether Bell or Magendie had earned priority in this discovery, historians have largely lost sight of the broader landscape. The exclusive association of sensibility and contractility with the neuromuscular system - a general- ity upon which the Bell-Magendie law logically depends - was scarcely a decade and a half old when in 1822 Magendie announced his experimental result. Magendie’s alleged predecessor Bell, as well as his colleagues Legallois and Flourens, had all assumed (as had Magendie himself at the outset) that single nerves subserved both sensible and contractile functions. And in 1821, after having waited “for a long time” for suitably young animals upon which he could operate to sever the posterior root, Magendie first observed that the corresponding limb was “entirely paralyzed; it was insensible.” In other words, and it is worth underscoring the point, even in his report on the distinction between the functions of the separate roots, Magendie initially used language which conflated paralysis (lack of motion) and insensibility (lack of feeling). That would explain his “great surprise” (announced a few

46. Olmsted says that this is not actually the case in Franqois Magendie, p. 55. 47. Ibid., p. 54.

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sentences later) when he saw the limb move even though it remained insensible. Only then, he wrote, did he determine to cut the anterior root, leaving the posterior root intact. This difficult procedure success- fully accomplished, Magendie saw the associated limb become “flaccid and immobile” while it remained sensible.48 Hence the dorsal and ventral roots subserved distinct functions - sensibility and contractility, respectively.

The reason for emphasizing that Magendie thought he had observed something new (and not that he had merely replicated a procedure or sustained a theory of Bell’s) is not to resurrect once again the priority controversy.49 Rather, the aim is to relocate the “discovery” of the Bell-Magendie law in its broader context: a relatively focused and persistent concern with locating sensibility and contractility only in neuromuscular structures, and as specifically as possible. It is interesting to speculate as to whether, in motivating this discovery, the influence of general research objectives were supplemented by specific hints from Cuvier. For in the Leqons d’anatomie cornparke of 1805 Cuvier had wondered whether the same part of the nerve transmits sensations and motion and why in some clinical cases motion, but not sensation, remained in an injured limb. Likewise, he had wondered why rejoining a cut nerve may restore mdtion but not sensation.50

Even as he wielded the scalpel, Magendie did physiology with the pen. For instance, his 18 16-l 8 17 Prtcis &ltmentaire de physiologic had a most unusual tone for a textbook: instead of trading solely in established truths, it also raised questions about widely accepted views on many of the subjects it treated. One particularly relevant example is Magendie’s insistence that the use of sympathetic nerves is “unknown” and that all hypotheses - including Bichat’s belief that it was the center of organic sensibility - were a mere “jeu d’esprit.“5’ Moreover, Ma- gendie’s textbook included psychological theories which removed metaphysical supports from Bichat’s system. Magendie subordinated

48. Franqois Magendie, “Experiences sur les fonctions des racines des nerfr spinaux,” J. Physiol,. 2 (1822), 216-219.

49. See Paul F. Cranefield’s The Way In and the Way Out (Mt. Kisco, N.Y.: Futura, 1974) and Michael Gross, “Bell, Magendie, and the Spinal Roots,” Ap pendix 3 of “Function and Structure in Nineteenth Century French Physiology,” Ph. D. diss., Princeton University, 1974.

50. Georges Cuvier, Lecons d’anatomie cornparke (Paris, 1800-1805), II. 110-112.

51. Franqois Magendie, An Elementary Compendium of Physiology, trans. E. Milligan (Edinburg: John Carfrae, 1823), p. 81n.

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emotions to the intellect and, localizing both in the brain, thereby argued against a system which traced emotions to local sensibility in the visceral organs. Magendie’s psychology thus became one more element in the attack on local sensibility. Echoing Cuvier’s 1805 statement that all sensations pertain to the central nervous system,52 Magendie sup- porteds3 Cuvier’s point that “it is not external organs in which we feel but only the center of the nervous system.” 54 Internal feelings were transmitted to the cerebrospinal system, where they occasioned wants, which were among the ingredients of rational thought, rather than incompatible with it, as Bichat had believed. The passions “are internal sensations; they can have no seat. They are the result of the action of the nervous system, and particularly that of the brain.“s5 This dis- agreement was conducted entirely in terms of philosophical argumenta- tion based often on subjective psychological experiences, a fact which suggests that Magendie was concerned not simply with the results of experiments but also with establishing one physiological attitude in place of another. Unsurprisingly, his descriptions of passions and emotions are abstract, and the vivid descriptions of visceral experiences and expressions of feeling found in works such as Bichat’s are altogether missing in Magendie’s treatment. On another level of psychological analysis, Magendie referred to the soul as “an emanation of the Divinity,” yet asserted that it must be considered “the result of the action of the brain,” and that it should not be distinguished from “the other phenomena which depend on the actions of that organ.” With the seat of emotions shifted from body to brain, feelings became intellectualized. For instance, where Bichat has morality almost inevitably at war with pleasure,56 Magendie sees the problem in intellectual terms: happiness means not physical pleasure but fulfilled desires, where desires depend on judgment; and , should will conflict with a rational calculation of what can be obtained, we should “give such a direction to our desires that we may be enabled to obtain happiness.“57

In 1822, Magendie carried the attack into Bichat’s own territory by issuing an edition of Bichat’s Physiological Researches on Life and

52. Cuvier, Anatomic cornparke, 11, 105. 53. Magendie, Elementary Compendium, p. 108. 54. Cuvier, Anatomic comparke, II, 106. 55. Magendie, Elementary Compendium, p. 98. 56. Bichat, Physiological Researches, p. 48. 57. Magendie, Elementary Compendium, p. 115. Likewise, man’s “natural

wants” (e.g., food, water, sex) are “the most diversified of any animal,” Magendie asserts, “in proportion to his intelligence” (p. 117).

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Death, which he published so that he might protect young medical students from “error.” While noting that Bichat’s text had won praise from “exact minds” for its observations and experiments, Magendie asserted that it had gained popularity for its vague explanations. The latter he questioned or refuted in long and detailed annotations, found- ing his criticisms as much on meta-scientific and logical considerations, and on thought experiments, as on actual laboratory results. They converge in a general critique of Bichat’s way of thinking about the living organism.

On the most general level of characterizing life, Magendie objected to Bichat’s assumption that the organic system of animals and plants carry on analogous nutritive processes by means of a kind of sensibility. Magendie insisted that sensation implies the existence of a nervous system, found only in animals. 58 Yet, he used his own studies of the esophagus in swallowing and peristalsis as evidence that at least in some cases the “animal” cerebrospinal system exerts control over organs of the “organic” system.

He took a positivistic line by condemning organic sensibility because there was no observable evidence for it. By the same token, he remarked that no one has yet seen that “partial movement of oscillation in each fiber, in each molecule,” which Bichat had called insensible organic contractility.59 But his assault on sensibility was logical as well as methodological. He criticized the quantitative language Bichat had used in describing sensibility, for instance in referring to the blood vessels “each of which has its own proper sum of sensibility which puts it in relation with such or such a fluid.” Magendie replied (a priori) that quantitative language like “dose” or “sum” was inappropriate for such incalculable things as sensibility. 6o He also sought contradictions in the

58. Bichat, Physiological Researches, p. 12n. 59. Ibid., p. 128n. 60. Ibid., p. 87n. Magendie was not by any means antiquantitative, however.

In fact, he went on to recommend a study of the motion of fluids in a system of canals with the same physical conditions as the system of veins and arteries, in preference to “casting myself entirely in the field of hypotheses by supposing for the small vessels a sensibility or a contractility which evidently does not exist at all in the large” (p. 112n). According to Bichat, circulation in each organ was “withdrawn from the empire of the heart” and independently controlled in each organ by its local sensibility. If so, blood flow in the veins would depend on the state of the organ the blood passed through rather than on the impulsive force of the heartbeat and the elasticity of the vessels. Magendie’s study of circulation had shown; however, that even in veins “the action of the heart still makes itself felt in modifying the course of the blood” (p. 116n). See also note 43, above.

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concept itself, remarking, for instance, that organic sensibility, if indeed it existed, “would be found continually at fault” since it allows not only properly digested thyme, but any mixture, to leave the stomach; it permits the absorption of noxious fluids; and it causes contractions in a heart devoid of blood.61 Magendie drew also on thought experiments - for instance, to refute Bichat’s claim that the arterial walls must possess sensibility because circulation of a foreign fluid causes pain6*

As in his textbook, so in his notes on Bichat’s monograph Magendie criticized Bichat’s psychological doctrines largely on a priori grounds. For instance, Magendie commented on Bichat’s observation that the effect of fear is a stricture of the stomach (local sensibility/organic contractility) with the observation that fear deprives some individuals of the use of their legs but one would scarcely call such individuals’ legs the seat of their passions. Likewise, he cannot believe that when Bichat said “the brain is never affected by the passions” he meant it. Instead, Magendie reformulates the notion of passion so that intellectual operations are crucial: for instance, a man gets angry at news of a disadvan- tageous event only because “he examines the event in itself, and its relations with antecedent and future events,” judges himself injured, and, “from a knowledge of this only, his heart is sympathetically affected.” That is, the ratiocinative determination of this emotion “exists before the agitation of the heart [which] is the effect of it and not the cause.“63

In summary, Magendie rejected Bichat’s array of animal and organic sensibility and contractility, sensible or insensible. He argued for the localization of contractile phenomena in muscle fiber (their being dependent, however, upon the participation of nerves); for the localization of sensation in the cerebrospinal system; for the localization in the same system of control over at least some of the actions of the organic system; and for the substitution when possible of physical analogues like diffusion and hydraulic models for explanation invoking local

61. Ibid., p. 82n. He made an analogous criticism of the role of local sensibility in salivation. Sensation can be aroused only by direct contact of the sensing part with the substances to which it responds, but salivation can occur merely upon the sight of food; so local sensibility in the salivary duct could scarcely be the cause of salivation.

62. If an irritating substance were injected into a section of artery tied off by ligatures, he claimed, no pain would occur until these were removed; then, once the irritating substance reached any “sensible part in the cerebrospinal system, we can easily conceive that the animal must experience pain” (ibid., p. 85n).

63. Ibid, pp. 57n, 69n (my italics).

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sensibility. Finally, he seated emotion, instinct, and passion not in the viscera but in the cerebrospinal system, as complements of rational thought; emotional feelings were a product of reasoned judgment.

What Magendie accomplished for the spine - separate sites assigned to its two distinct functions of sensibility and motility - Flourens almost simultaneously attempted for the brain. His research began about 1819 with the initial aim of distinguishing between cerebrum, cerebellum, medulla, and spine, on the basis of their differing properties of sensibility and irritability. 64 By irritability he meant what others were then calling contractility.

In March 1822 Flourens described for the Academic des Sciences the results of his “physical researches” on the properties of the nervous system.65 He established that “irritability” - the ability to solicit

64. Flourens may have been motivated partly at least by his dissatisfaction with growing confusion about the use of the terms “irritability,” “sensibility,” and “contractility” during the half-century since Haller had assigned sensrbility to nerves and irritability to muscles. As he wrote (in his “Recherches physiques sur les prop&es et les fonctions du systeme nerveux dans les animaux vertebres,” Arch. Gen. Med., 2 [ 1823]), during the intervening period, the distinction had blurred and the terms had multiplied: “The contractility of Bichat is the irritability of Haller; the elastin’ty of Haller is the irritability of G&son; the contractility of Bichat and the irritubility of Haller are only particular cases of the sensibility of Cabanis and of LeGallois” (p. 327). He found unacceptable the yse of a single cause (sensibility) to explain the distinct phenomena of perceived and unperceived actions, as well as of movements commanded by the will. Thus he sought to return to Haller’s unitary use of sensrbility to explain “the distinct phenomena of sensation,” and to restore the independent use of the term “irritability,” which had been contlated with “sensibility.” By 1830, besides his findings on the func tions of the cerebrum and cerebellum, he gave greater precision to Legallois’s localization in the medulla oblongata of the site controlling respiratory motions, thus affuming Legallois’s arguments for the participation of Bichat’s “animal” system in the so-called organic, or vegetative economy.

65. Although Robert Young describes this work fully in his Mind, Bruin, Qnd Adapfion in rhe Nineteenth Century (Oxford: Clarendon Press, 1970), he relies on Flourens’s somewhat misleading restatement of his findings in the wake of Cuvier’s suggested reforms in their expression and interpretation. Thus Young treats Flourens’s psychology as a personal invention, whereas Flourens’s original paper suggests reliance on Condillac’s sensationalism and his later papers owe much to Cuvier’s somewhat different ideas.

Flourens’s early interest in sensationalist psychology is further suggested by the fact that Destutt de Tracy attended his 1821 course at the Athenee Medicale in Paris titled “The Physiological Theory of Sensations*’ and Flourens wrote to de Tracy that the latter’s ideas had “awakened” some of his own. See G. Legee, “M. J. P. Flourens (1794-1867) et Destutt de Tracy (1754-1836),” Hist. Nat., 4 (1974) 95-98.

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motion from contractile or muscle tissue - was a “property” of the nerves and of only that part of the central nervous system in which white matter surrounded gray matter and from which nerves originated, i.e., medulla and spinal cord. “Sensibility” - the ability to feel dis- turbances caused by the stimulation of sense organs or of nervous fibers - was the property of that part of the central nervous system in which gray matter surrounded white, and from which no nerves arose, i.e., the cerebrum.

Flourens’s methods included cutting and tying nerves and removing nervous tissue by successive slices. Studying primarily the nervous system of pigeons, he severed or ligated peripheral nerves and various parts of the spinal column in order to isolate them from their connection with the anterior parts of the central nervous system (i.e., the parts near the brain). When so separated, they continued to excite contraction in the muscles they innervated when they were artificially irritated by pinching, tearing, etc. This property, he found, persisted as high up in the cord as the medulla oblongata or the bigeminal or quadrigeminal tubercles. But in the intact nervous system, no irritation of the cerebrum, cerebellum, optic layers, or striated bodies elicited any motion. Moreover, a nerve or any part of the spine, once deprived of its connection with these anterior parts of the central nervous system, no longer elicited pain when disturbed. From this result, he concluded that pain, and thus sensations, were felt in some part of the brain.66 Flourens’s most compelling evidence for the discrete localization of sensibility and contractility obtained, however, from effects on the eyes. Removal of a single cerebral hemisphere destroyed sight in the eye on the opposite side; nevertheless, “a capital fact,” the contractility of its iris persisted. Therefore, he concluded, sensation and motion

66. Further evidence for this association depended upon some psychological reasoning. Removal of both hemispheres left the animal, usually a pigeon, in a “perpetual sleep, and even deprived of the faculty of dreaming during this sleep . . . it gave no sign of will.” It repeatedly thrust itself against some obstacle, whereas a normal animal would have soon turned aside. Placed on its back, it righted itself; it drank water put in its beak; it resisted efforts to open its beak; it beat its wings when disturbed; it excreted; “the least irritation disturbed and troubled it” (Flourens, “Recherches physiques,” pp. 351-352). By repeatedly hurling itself against some obstacle, it evidenced lack of judgment. It retained all organic functions, such as swallowing water, yet evidenced none of the functions based on sensation, according to Flourens, such as the will to repeat the sensation of tasting water. He supposed that these behaviors meant the animal had lost sensation, which he located in the cerebrum.

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could be dramatically distinguished, both functionally and anatomically, in the central nervous system.67

In attempting a like analysis of cerebellar function, Flourens found that sensibility and irritability were not adequate concepts.68 Removal of the cerebellum made the animal incapable of standing or of success- fully executing the coordinated movements of walking, jumping, flying, etc., although it continued to try to move and so retained its will and sensibihty. Moreover, the poorly coordinated motion which resulted upon removal of the cerebellum could not be due to sensations of pain for “in the midst of these contortions so unregulated, so impetuous, so petulant, there was not the least sign of convulsions.“69 Consequent- ly, the cerebellum is neither a seat of sensation nor an excitant of motion (for these pertain instead to the cerebrum and medulla, respectively). With the cerebellum thereby neither sensible nor irritable, Flourens himself almost acknowledged the futility of his original objective of analyzing the nervous system into two distinct systems only, based on the preconceived functional dichotomy between sensibility and irritability: “Sensations, contractions, the joining of these contractions into unified movements in jumping, flying, walking, or standing still, etc., the volition of these movements; all these phenomena are thus independent; the organs from which they derive, distinct;their isolation, manifest ; their localization, demonstrated.” ‘O The simple functional language had collapsed under the weight of two important new functions: the coordinative or regulatory function of the cerebellum, and a function related to “volition”, which was also distinct from both sensibility and irritability. It was only a review and reinterpretation of Flourens’s results which clarified those concepts.

The reviewer, Georges Cuvier, reporting to the Academic on Flou- rens’s work, affirmed that perception, consciousness, and intelligence did indeed all disppear with the loss of the cerebral lobes. While Flourens

67. However, not until he read Magendie’s results did he distinguish between sensible and contractile portions of the spinal cord or its nerve roots; initially he had associated the spine with irritability and had thought nerves were bifunctional.

68. This portion of his research almost drew him into a miniature priority controversy of his own with the Italian Luigi Rolando, who had been cutting up the cerebellum in the same way, but for a different reason: to show it functioned like a galvanic apparatus. See Ermanno Manni, “Luigi Rolando, 1773-1831,” Exp. Neural., 38 (1973), 1-5.

69. Flourens, “Recherches physiques,” p. 359. 70. Pierre Flourens, Recherches experimentales sur les proprit?tb et les

fonctions du systCme nerveux (Paris: Ball&e 1842), p. 368.

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said that this evidenced loss of sensation, in fact sensation did not disappear; for, Cuvier reasoned, if the animal moved when disturbed it evidently felt the disturbance. Yet it had lost something, for the decerebrated animal did not move spontaneously and hence it had no will. Cuvier here was reformulating his own 1805 interpretation of Legallois’s work, which, he thought, showed sensibility and will to persist in a decerebrated frog or tortoise.‘r Manifesting no sign of will, Flourens’s birds thus must have forgotten everything, and so, having instantly forgotten the obstacles they had crashed into a moment before, they again plunged into them. “Perceptibility” was Cuvier’s term for the cerebral faculty of comparing immediate sensations with memories,72 to make judgments or volitional intentions. These in turn manifest themselves as spontaneous behaviors which are lost in decerebrated specimens.

Cuvier had also criticized Flourens’s redefinition of the term “irritability,” which Haller had used, Cuvier said, in a perfectly acceptable way to mean the capability of muscle fibers to shorten when stimulated. Furthermore, and quite suggestively, Cuvier observed that Flourens was using this singie term to describe two distinct phenomena: conduction of irritation and conduction of sensation. But though Cuvier was thereby referring to a functional distinction between sensation and contraction which Magendie had just localized anatomically, he made no mention of the latter’s findings. Magendie had announced his results on the spinal roots in the June number of his journal, but Cuvier’s report on Flourens’s work, published on July 22, 1822, made no mention of them and he may well have been unaware of them at the time he wrote the report.

In the published treatise - the title changed from “Physical Re- searches” to “Experimental Researches” - Flourens accepted Cuvier’s terminology, replacing “contractility” by “irritability” and distinguishing “perceptibility” from “sensibility.” But Flourens’s general beliefs about psychology suggest even more strikingly than a revision of nomenclature the imprint of Cuvier’s beliefs. During some four decades, Flourens repeatedly deployed his experimental findings on the brain to deny the phrenological theories of Franz Joseph Gall. Yet his first assessment of Gall was far more charitable and seems to have undergone a reversal only as he became more closely affiliated with Cuvier. Cuvier had himself opposed Gall’s ideas as early as 1808, when he reported to

71. Cuvier, Anatomie compade, II, p. 93. 72. Flourens, Recherches experimentales, pp. 78-79.

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the Academic on Gall’s and G. Spurzheim’s Recherches sur le systkme nerveux. But Flourens criticized Gall - more vociferously and persist- ently than Cuvier himself - only after 1822, once he had publicly come under Cuvier’s aegis. Thenceforth, he interpreted all his work on the brain as evidence of its functional unity and equipotentiality, which was the view Cuvier favored (because it made the entire brain the material instrument of a unitary soul). In contrast, Gall’s phrenological theories had treated the brain as an assemblage of organs each diversely specialized for a particular faculty such as carnivorousness, self-defense, language, or poetical talent.

Earlier, in 1819, despite mild doubts about Gall’s specific choice of faculties, Flourens had been enthusiastic about the phrenological belief that there existed no unitary perception, memory, and judgment in the brain as a whole, and that instead each faculty had its own site and correspondingly its own perception, memory, and judgment.73 He added that such a belief was compatible with experiments in which the brain was destroyed by successive slices.74 This very procedure, which in 1819 gave results compatible with Gall’s concepts, was the one he employed in 1823 to deny Gall’s views. Replying to some of Cuvier’s objections to his first, 1822, memoir, he described further ablation experiments which now established what Cuvier had proposed in his critique of Gall: that the cerebral lobes acted as a whole - and either functioned fully or not at all - rather than piecemeal as a collection of separate organs, each the instrument of a particular faculty of the s0u1.‘~ In short, Flourens’s anti-Gall views, which endured through

73. For instance, one of Gall’s faculties was the sense of localities. And if its hypothetical organ within the cerebrum were removed, Flourens declaredin 1819, “relative to space there will be neither perception, nor memory, nor judgment” (Pierre Flourens, review of F. J. Gall, Anatomie et physiologic du systkme ner- vew, Rev. Encyc., 5 [1819], 457466).

74. Impressed then only with the animal’s failure to express pain, he did not indicate whether the parts so removed eliminated a specific kind of sensation, as Gall’s view would have suggested (ibid., p. 465).

75. Tenon et al., in their report on Gall’s treatise on the properties and func tions of the nervous system, Amd. Sci. Proc. Verb., 4 (1808), 4962, expressed Cuvier’s reservations. The commission reporting on Flourens’s work, which Cuvier chaired, had objected that, while Flourens had indeed proved that ablation of the hemispheres abolished vision and hearing, he had not proved that the other senses were also injured Flourens showed in new experiments that all senses were suddenly and totally abolished once the damage caused by ablation went too far. And as the wounded brain healed, all senses were recovered simultaneously, a fact which Flourens saw as an argument for the unitary, indissociable functioning of all faculties of an intact brain.

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his later career, emerged only after he came publicly under Cuvier’s stewardship.

CUVIER, THE ACADRMIE, AND INSTITUTIONAL SUPPORT FOR THE NEW PHYSIOLOGY

The Academic des Sciences fostered the transformation of physiology described above. Other Academicians supported Cuvier’s position by praising work of the kind he sought to promote: official reports on physiological research by members of the Academic (between about 1800 and 1825, the period during which they were published in the Pro& verbaux) singled out for particular commendation two aspects of the papers they treated. First, they emphasized those results which assigned sensibility and contractility to specific sections of the neuromuscular system. Second, they encouraged the use of experimental methods - in particular the use of visible movements to establish contractility, and of apparent pain (convulsions) or evidence of vision, audition, olfaction, etc. - to establish sensibility.

The commission reporting on Legallois’s studies recommended that he be given funds to defray past and future expenses required for his work. The report demonstrated exhaustively that all of the work was original (even in two cases where he reported earlier experiments, but put a wholly novel interpretation on them). The commissioners judged that Legallois’s work had no precedent in physiology; no previous work had been at once’ so extensive and its parts “so connected and so dependent upon each other that to arrive at the perfect explanation of a fact, it is necessary to reascend to all those by which the author has arrived at it.“76 They were outspoken in their enthusiasm:

The opinion of your commissioners is that the work of Dr. Legal- lois is one of the most beautiful and certainly one of the most important that has ever been produced in physiology since the learned experiments of Haller; - that this researcher, so modest, so diligent, so praiseworthy, deserves that this class should grant him its special benevolence, and also the encourgement which may be its power.”

Magendie entered physiology as an armchair theorist; this career, which lasted less than a year, was followed by a virtual obsession with

76. Legallois, Experiments, pp. 287-288. 77. Ibid., pp. 293-294.

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publicizing experimentation as the only valuable approach to physiology. (In that way he overlooked the dependency of his own ideas on nonexperimental factors.) With the first experimental paper he published in 1809, the Academic’s response supplied unambiguous guidance about what good science meant. The commissioners praised Magendie’s and Delille’s collaborative work on the arrowhead poison for their “severe experimental route” and their “having removed with care all gratuitous and frivolous explanations and . . , restricted themselves to simple facts and relationships of observed facts.“‘* If the commission analyzing Magendie’s 1813 absorption work found his conclusion “still a bit premature,” nonetheless it appreciated his sagacity in varying experimental procedures and recommended that he receive “all the encouragement he deserves,” not only because of his “natural sagacity” (again) but also because of “his manner of proceeding in his experiments with an extreme reserve.” 79

Reporting on Magendie’s study of vomiting, another commission urged that the president of the Academic invite him to pursue the work further and repay him for past expenses while making advances necessary for further work.*O The report detailed the significance of the work as an exemplary contribution to “one of the greatest needs of physiology,” namely, “to learn in a precise manner the proper function of different parts” of the s’pinal cord.*l

78. Pelletan et al., “Rapport du memoire Mm. Delille et Magendie qui a pour titre ‘Examen des effets de Pupas antiar et de plusieurs substances em&iques,‘” Acad. Sci. Foe. Verb., 4 (18091, 275-277.

79. P. Pine1 et al., “Rapport du memoire de M. Magendie SUI les organes d’absorption dans les mammiferes,” Acad. Sci. Proc. Verb., 5 (1811), 142-146.

80. One reason that Magendie’s study of vomiting so pleased the commissioners was that it confnmed Legallois’s work. The regarded it as “a particular and very remarkable application of that general truth demonstrated by M. Legal- lois, namely, that the seat of the nervous power (the brain and spinal cord) is the unique source of all the movements which occur in the living animal and that any part whatever can execute no movement without a particular and prior modiflca- tion of the portion of this seat by which it is animated . . . It is quite probable that most of the substances which have some effect on the animal economy act in this manner, which leads to entirely new views on the action of most medica- ments and poisons.” See G. Cuvier et al., “Rapport sur le memoire de M. Magendie relatif au vomissement,” Acad. Sci. Proc. Verb., 5 (1813), 174-179.

81. The report continued, perhaps somewhat coyly, “The need for and the severity of analysis have changed ideas and perfected judgment, and one knows what institution has the right to glorify itself for having instilled this great movement and give this useful example. Nobody has been more faithful to these principles than M. Magendie. He has never presented himself before us without

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And, in the same year, 1813, his study of the action of emetic drugs demonstrated “the patience, perseverance, and sagacity of M..Magendie in research which he knows how to render profitable to science.“s2 The commission invited him to think of himself as one of their own (although his election to the Academic was ln fact still eight years away) : “this young and diligent doctor has acquired a surfeit of titles and rights to the esteem, the good will, and the gratitude of the class which, for a long time already, has liked to count him among the scientists which bring to it with the greatest promptness the tribute of their medltations.“s3 To those weighty words, coming from among the most renowned scientists of his day, Magendie responded appropriately, turning his back on a nascent surgical career and striking out on his own as an experimental physiologist.

Here too, in terms of professional advancement, Cuvier and the Academic impinged on the careers of Magendie and Flourens. In 1813, in that “volte-face” (Flourens’s term) from surgery to physiology, Magendie resigned as prosector of anatomy of the Paris Faculte de Medecine and announced a course of private lectures in physiology. This turnabout has been ascribed to a personality conflict between Magendie and Chaussier, a prominent surgeon and Faculte professor of surgery; or to Magendie’s decision to avoid professional rivalries with either Dupuytren, the head of the Faculte’s anatomy laboratory, or Bicherand, a rising young surgeon. a4 But accounts of Magendie’s career often mention his preoccupation with being accepted into the Academic without drawing an obvious conclusion: with frustration looming in a medical career, effusive praise in the Academic in 1813 for a series of his memoirs may have pointed out to Magendie the path to tread in making haste from those difficulties. Elected to the Academic, however, only in 1821, Magendie began immediately and vigorously to participate in commissions reporting on physiological research.

being surrounded by demonstrations and all the memoirs with which he has paid homage to the section consist in proofs and facts.” Magendie was further labeled an “able experimenter . . . as judicious [as] an anatomist as [he was] severe [as an] experimenter.” Magendie apparently wanted the relationship to continue, for, the commission’s report observed, he “has never offered to the section a tribute of his distinguished talents without having at the same time contracted to soon offer it another.”

82. Cuvier et al., “Rapport sur le memoire de M. Magendie relatif a I’action de l’emetique,” Acud. Sci. Proc. Verb., 5 (1813), 244-248.

83. Ibid. 84. Olmsted, Magendie, pp. 4849.

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In the same year the Academic de Medecine in Paris also added him to its rolls.

Flourens’s two most recent biographers agree that Cuvier influenced Flourens from the start of his career; one calls him Cuvier’s proteg&85 It may be no coincidence that Flourens began his research on the nervous system the same year that Cuvier announced in the Academic a prize for the functional description of the parts of the braina In 1832, at Cuvier’s request, Flourens succeeded him in the post of Perpetual Secretary, having already received the Academic’s important Monyton Prize in experimental physiology twice in sucession (in 1824 and 1825) for his studies of the nervous system. In 1828, he had been elected to the Academic and had become Cuvier’s deputy lecturer at the College de France; on Cuvier’s death in 1832, he at once became professor there.

THE INFLUENCE OF ZOOLOGY AND THE PHYSICAL SCIENCES ON THE NEW PHYSIOLOGY

The transformation in physiological theory and research discussed above involved a systematic critique and reformulation of eighteenth- century concepts of sensibility and contractility. These properties were denied to structures other than those of the neuromuscular system and were allowed no role in metabolic processes such as selective absorption or assimilation. Moreover, the removal of feelings to the neuromuscular system included a reformulation of the psychological relationship between emtions and thoughts. Viewing emotions as ideas formulated in the brain, which may or may not have a bodily or organic component, was an arbitrary position for which Magendie had no experimental and scarce anecdotal basis.

As to the sources of this transformation, several suggestions can be derived from existing historiography. One possibility is that the theoretical change depended on the novel use of experiments to upset previous theories based on observation alone. This interpretation W. R. Albury lays to rest by showing that the eighteenth-century tradition was compatible with experimental investigation, as exemplified by

85. V. Kruta observed this relatiohsip in his essay on Pierre Flourens in Dictionary of Scientific Biography (New York: Charles Scniner’s Sons), VIII (1973), 132-135. Olmsted made a similar estimation in “Pierre Flourens,” in Science, Medicine, and History, ed E. A. Underwood (London: Oxford Univer- sity Press, 1953), II, 290-302.

86. Acad. Sci. Proc., Verb. 6 (1819), 426.

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Bichat’s work in particular. s7 Another suggestion is that the new views really owe more - as J. M. D. Olmsted’s biography of Magendie im@%ed - to the methods or prestige of the physical sciences. We can test this claim to some extent by examining how Cuvier and Magendie felt about the success and the potential of the new chemistry which had emerged around the turn of the centruy. While the prestige and power of the physical sciences did impress them, both Cuvier and Magendie, as will be shown below, expected little help from the physical sciences in solving the major problems of physiology and were not overly optimis- tic. A good deal of insight into this change comes from looking not outside but within the biological sciences - in particular at the relationship between zoology and physiology. There, as will be discussed below, we can observe the penetration of certain zoological assumptions into physiological theory.** The next two sections analyze the change in concepts of sensibility in terms of the influence on physiological theory of attitudes previously formulated for zoology, and evaluate the extent to which physics and chemistry supplied relevant knowledge or inspired new approaches to such problems.

“‘Zoological ” versus “Medical” Physiology

The delimited analysis of sensibility has two fundamental theoretical

87. Albury, “Bichat and Magendie,” pp. 58,83-84,118n47. 88. Albury clarifies and enriches Schiller’s suggestion that physiology achieved

its independence from anatomy via a concept of function which transcended the role of any single anatomical element or organ (see note 1, above). Still, it is striking that the bulk of the work on the localization of sensibility and contractility is best characterized by the most anatomically oriented of Magendie’s categories for studying a function: “the study of the action of each organ in particular to evaluate its contribution to the function” (Elementary Compendium, p. 20).

While Albury concurs that Cuvier’s ideas were important, the alliance with Cuvier should suggest that liberation from anatomy might be too cryptic a way of describing the rejection of the methods and assumptions of pathological anatomy combined with the acceptance of the assumptions of comparative anatomy. Albury himself drops the important hint that, as a result of Cuvier’s influence, “the directive idea of Magendie’s experimentation was biological rather than anthropomorphic” (“Bichat and Magendie,” p. 125n324); he might as easily have said “zoological rather than medical.” For the coherence of the multifaceted attacks on local sensibility suggest that something more than experimental fmd- ings are defining the functions to be researched. That coherence follows from the rejection by physigogists of both the theoretical assumptions and the specific content of the pathological anatomists’ local sensibility explanations, from their adoption instead of the assumptions of the comparative anatomists, and from their pursuit of those experiments suggested by such a reformulation.

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aspects which reveal a debt to zoological thought. One is that zoologists had for decades associated sensibility and contractility solely with the neuromuscular system. The other is that nutrition had long received considerable emphasis among zoologists as a central theoretical problem, but one to which sensibility and contractility were not relevant. For the zoologists perceived that nutrition was universal to all organisms, while sensibility and contractility pertained only to the neuromuscular system of animals. Moreover, while sensibility and contractility emphasized change and variability - which certainly reflected the clinical experiences of physicians - as an explanation of nutrition these properties would not suffice for zoologists, who were struck, rather, with its constancy. Thus any law of nutrition had to explain not the variability of pathological lesions in anatomical specimens but rather stability of structure - a stability so reliable that, as Magendie noted, one could determine in a rigorous manner all the phenomena of the life of an animal simply by considering one of its organs, a tarsal bone, for example.89 In other words, in its broadest ramifications, the nineteenth- century workers’ response to the medical approach to physiology grew from contrasting disciplinary commitments: in viewing living organisms, a zoologist would be quite likely to have a different set of preoccupa- tions and concerns than would a physician, The following exegesis of Cuvier’s general ideas about the province of sensibility and contractility and about nutrition and metabolism shows those same ideas, on the one hand, reflecting currents running through the views of earlier and contemporary zoologists and, on the other, reappearing in the early statements of Magendie.

Fundamentally, Cuvier’s views as expressed in his 1808 Rapport historique parallel those of such zoologists and natural historians as J. B. Lamarck, A. Dumeril, A. Daubenton, and Georges Leclerc Comte de Buffon. In contrast to the medical theorists, Cuvier held that sensibility was not a universal characteristic or distinguishing attribute of living organisms in general, but pertained only to animals. Lamarck, in making a similar distinction, deliberately contrasted his views with those of the physicians Cabanis and Richerand.9o While Buffon did not

89. Magendie, “Quelques id&es,” p. 112. 90. J. B. de Lamarck, ZooZogicul Philosophy, trans. High Elhot (London:

Macmillan, 1914). pp. 207, 226-229. Lamarck thought animals are irritable (i.e., they can move suddenly as a result of external of internal stimuli; p. 195), but not necessarily sensible (p. 53). He averred that only animals with a nervous system can sense, and further claimed that sensibility has nothing to do with the cause of either nutritional processes or irritable movements (p. 220) as any student of

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assert so absolute and clear-cut a distinction between plant and animal, he nonetheless emphasized a general contrast: in most instances, only animals evidenced “progressive motion,” and sensation or “the faculty of perceiving and of comparing ideas.“91 Daubenton distinguished more absolutely between plant and animal, for, he asked rhetorically, “how could one think that true plants have nerves, feelings, and spontaneous movement? A being of such a conformation is not a plant: it should be put in the rank of animals since it has all their properties, life, feeling, and movement.” 92 So only animals felt and moved, and this assumed a nervous system. The argumentative language suggests a conscious effort to confute an alternative point of view.

Besides differing from the physicians on the taxonomic criterion - maintaining that animals feel and move and, correspondingly, possess nervous systems - the zoologists held a contrasting view of nutrition and metabolism. While the physicians identified life with feeling and movement and treated nutrition and assimilation cursorily, the zoologists exhumed the traditionally important biological problem of nutrition and made it a defining characteristic of life. For them, the most striking thing about living organisms was their ability to maintain an organized structure. For the medical theorists, metabolic processes were only one of diverse manifestations of sensibility and contractility; they had little in detail to say about them and no program for studying them further. But the zoologists were fundamentally interested93 in the forces underlying nutrition and assimilation: as the process formative of anatomical structure they were the source of constant structural

“organization from the simplest animal up to man” readily perceives (p. 11). Likewise, Dumdril wrote in his ZooZogie analytique (Paris: Allais, 1806), p. 2, that while all animals react to the contact of external bodies, only some - presumably those with nerves - sense.

91. The oyster was an example of an animal which lacked these faculties, he noted. See Buffon’s Natural History General and Particular, trans. William Wood (London: T. CadelI & W. Davies, 1818), II, 356.

92. A Daubenton, “Introduction a l’histoire naturelle,” Encyc. methodique. Histoire naturelle, I (Paris, 1782), xiii.

93. Writing in his Traitk klkmentaire d’histoire naturelle, (2nd ed. [Paris: Deterville, 18071, p. 57) that nutrition was the only process characteristic of both plant and animal life, Dumdril noted too that only animals have sensibility and motility. Lamarck agreed that nutritive processes were fundamental because they were responsible jointly for organic form and function (Zoological Philosophy, p. 51). Buffon’s “molecules organiques” were his attempt to explain the development and production of organic forms.

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differences between types, which, in turn, guaranteed the certainty and reliability of comparative anatomical research.

Thus, from a more philosophical outlook, such as Buffon’s or Cuvier’s, the general laws governing organic form would arouse deep interest, for, ultimately, they must be the physiological basis of comparative anatomy.94 The physicians were not interested in constant differences among species. Rather, pathological anatomists sought in deformations of anatomical form in one species, man, to diagnose the fluctuating aches and inflammations of the diseased. Correspondingly, their account of assimilation, like their accounts of secretion or absorption, employed a concept of process and change - the transient feelings of sensibility - which also related to the experiences of sick patients.

Having posed constancy of form as the central question, Cuvier proceeded to speculate on what accounted for it. Just as ordinary chemical forces order the static form and composition of minerals, so, he suggested, a vital force maintains the form of structures of organic beings, although their material constituents change incessantly. (While Cuvier only went so far as to compare vital force metaphorically to physicochemical forces, Lamarck went beyond mere metaphor.95)

94. For decades, form was the standard basis for distinguishing living species from nonliving. Naturalists would refer to the development and maintenance of organic form in the former, as compared with the “accidental” formation and lack of organization of mineral crystals (i.e., their regularity and simplicity of structure).

In the mideighteenth century, Buffon had distinguished minerals and living organisms in accordance with his emphasis on the nutrition, growth, reproduction, and development manifested by living bodies (in his Natural History, pp. 355- 359). Thus, whereas plants and animals share “a species of animated organisation,” or specific organic structures, “minerals have nothing that approaches regular organs,” and lack “organization or the power of reproduction.” Daubenton took a similar tack. Minerals are not living because they lack organic form. Loss of the “conformation of their organs” is the natural cause of death in plants and animals, for they have lost thereby “the properties necessary for their functions.” (See his “Introduction A l’histoire natureBe,” p. xiii.)

95. By the action of caloric, Lamarck accounted for the phenomena Cuvier later attributed to vital force, suggesting, for instance, that caloric caused the “special tremor” involved in nourishing organic form through special kinds of chemical transformations. These chemical processes were analogous to fermenta- tions, but opposite in their effect. They resulted in assimilation rather than decomposition. (See his Zoologicd Philosophy, pp. 184-186, 212, 214-215, 220). Cuvier and Lamarck also differed with regard to the cause of muscle contraction. For Cuvier (in his Rnpporf historique, p. 21 l), contraction should be referred to a vital force: “movements are not produced by mechanical tremors or quiverings at

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Cuvier vividly mapped the program for physiology as a rapprochement between and synthesis of chemistry and anatomy:

[I] n living bodies, each part has its proper and distinct properties; none of their molecules remains in place; all enter and leave suces- sively; life is a continuous vortex . . . [T] he actual matter of the living body will soon be there no longer, and yet it is the depository of the force which constrains future matter to behave in the same ways as it. Thus the form of these bodies is more essential to them than their matter, since the latter changes incessantly while the former is conserved, and moreover it is the forms which constitute the differences of species, and not the combinations of matter, which are almost the same in all.

In a word, the form . . . becomes, in the study of living bodies, the dominant consideration and gives anatomy a role in it quite as important as chemistry.96

Life for Cuvier is ordered by forces which sustain structures built from incessantly shifting matter. Each “organic element,” which, in a mass, constitutes a different sort of organ, manifests a different sort of function. To learn the laws of the vital force meant studying “not only the general composition of animal principles, but the particular proportion of each separate principle”97 in the different organic elements; “the future of physiology” depended, he thought, upon the “analysis of forces proper to each organic element.“98 Yet Cuvier mistrusted direct recourse to the laws of physics and chemistry and wondered indeed if those laws were not incomplete even as accounts of inorganic phenomena: “Maybe the number of these chemical agents is greater than is thought; maybe indeed there are those which are still hidden from us and upon which will one day depend the explanation of a multitude of phenomena of nature, especially of living nature, today incomprehensible to US.“~~ In the meantime, vital force might stand

all, . . . there must be a constant productive source of force and movement.” For Lamarck, caloric caused the irritable shortening of muscle when the muscle was stimulated directly by mechanical means, while normal, powerful muscle contraction following stimulation of the nerves depended upon some component of the electric fluid distriiuted by the nervous system.

96. Cuvler, Rapport historique, pp. 187-188. 97. Ibid., p. 194. 98. Ibid., p. 218. 99. Ibid., p. 27.

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provisionally for the source of the special characteristics of living organisms.

Magendie’s “Several Ideas . . . ” of 1809 partook of Cuvier’s thoughts. Magendie’s basic objection to existing physiological explanation was that “the phenomena proper to organized bodies are not at all related to one and the same cause” but should be.loo Magendie proceeded to make a comment which vitiates his long-standing reputation as an anti- theoretical experlmentalist. While he did say that new experiments must be made to establish “most physiological facts,” he quickly brushed that aside and turned to the problem of COO many unrelated or unsubordinated facts. He wanted more clarity and comprehensiveness. How can the facts be comprehended? By seeing them as varied manifestations of the “general and essential character . . . observed in all organized beings during the whole duration of their existence.” lo1 It is noteworthy that Magendie thought that one simplifies, clarifies, and streamlines physiological theory by first deciding what phenomena are “general and essential” in living organisms: “if one admits vital properties, which is not an absolute necessity, they should be conceived of so as to belong to all living and organized beings.“lo2 Like Cuvier and the other zoologists, Magendie asserted that the crucial life phenomena are metabolic, nutritive processes formative of organic structure, not the sensibility and contractility of the medical theorists. And on that basis, he launched his assault against such properties as “insensible organic contractility,” which is not a vital property because it is not “a general and essential character of life.” The foremost example of a “general and essential” property is nutrition. According to Magendie, the problem with the medical theorists’ analysis was not their vitalism in general, for, like Cuvier, Magendie himself employed the concept of a “vital force.“lo3 It was their particular way of applying it to nutrition by first equating it with the properties of sensibility and motility.lo4

100. Magendie, “Quelques idles,” p. 107. 101. Ibid. 102. Ibid., p. 108. 103. Cuvier uses the term in his Rnpport historique, p. 211, as does Magendie

in “Quelques id&es,” p. 108. 104. The full text reads (“Quelques idles,” p. 109): “After having recognized

a particular force as the cause of the nutritive movement, rather than ardently giving themselves over to the search for the laws of this force - a search which would be, without exception, the most beautiful and most interesting subject of work which anyone could propose for himself - they wish instead to see, in some fashion, how each molecule animated by the vital force acts in order to produce this nutritive movement; and thus they gratuitously suppose that the vital force is

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Besides nutrition, the other “general and essential character” is a collection of activities that Magendie conjoined under the heading of “vital actions,” by which he meant such perceptible phenomena as the secretion of bile by the liver, the secretion of saliva by the salivary glands, the shortening of voluntary muscle - in short, anything the organism does besides nourish itself. These two categories, nutrition and vital action, are the distinguishing marks of living organisms. And since he sought to relate to “one and the same cause” all life phenomena, he found it (unsurprisingly) “very natural” to suppose vital action has the same cause as nutrition. This cause, vital force, “just like planetary and molecular attraction, is unknown in its nature but manifested by its effects.” But while he asserted that vital force should be studied by making inductions based on the experimental study of its effects,105 in fact his interpretation of vital force had no more to do with observable phenomena than did the medical theorists’. Less, in fact, since vital force pertained only to something which could not be seen:

the nature, the disposition, and the mode of union of living molecules - in a word, their organization - modify the vital force in such a way that the phenomena by which it is manifested in living bodies are always in a direct relation to the organization of those bodies . . .

Two living bodies with the same organization will exhibit the same vital phenomena; two living bodies organized differently will exhibit vital phenomena the diversity of which will always be in a direct (ratio) to the difference in organization.106

This is a refrain of Cuvier’s “analysis of forces proper to each organic element .” Magendie also adopted the contrast Cuvier and the zoologists had drawn between the static composition of minerals and the “double

manifested in each molecule of a living body by two properties; the first, sensibility (the faculty of feeling, that is to say, of experiencing a moreor less profound impression which changes the natural and usual rhythm of vibratility, etc.); and the second, motility (the faculty of movement which consists in a continual tendency toward contraction or tightening, etc.) . . . I refer to works of physiology in order to examine how nutrition is explained by means of sensibility and motility. Whatever explanations may be given it will be admitted that nothing in it is founded upon observation. What positive knowledge, then, do we have concerning nutrition?”

105. Ibid., p. 113. 106. Ibid., pp. 111-112.

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intestine movement” of composition and decomposition despite which living bodies sustain relatively constant structure for a time and then give rise to new bodies morphologically similar to themselves.lo7

For Magendie, then, metabolism was not a problem in modes of feeling and moving; nutrition had nothing to do with little spasms in the fibers. Nutrition and metabolism in general concerned the relationship between chemical processes and micro-anatomical structure. More- over, Cuvier’s and Magendie’s emphasis on nutritive metabolism - and even their terminology and imagery - were no transient idiosyncrasy; rather, they made their way into French physiological writing and there remained at least until the 1860s. Indeed, during that period, the search for some rapprochement between chemical theories and structural hy potheses persisted precisely as the two remained incommensurable. lo8

The Inadequacy of Chemistry

It seems natural to suggest that the concern with the chemistry of nutrition found in the works of Cuvier, Magendie, and their followers was inspired by the achievements in organic analyses of Lavoisier and his colleagues. After all, Magendie’s emphasis on metabolic processes appeared shortly after the first effloresence of elementary analyses of organic substances and the appearance of chemical models such as J. N. Hall&s animalization the&y. Furthermore, Magendie’s biographer, J. M. D. Olmsted, suggested that Magendie’s critical attitude toward contemporary physiology was “stimulated” by Laplace’s dissatisfaction, and that Laplace’s own interest in the subject grew from his collaboration with Lavoisier on the study of respiration.

But Magendie’s attitude towards Lavoisier’s work was in fact scarcely that of a reverent disciple. In 1811, he criticized a view he attributed to Lavoisier109 that animal heat resulted from an ordinary chemical combustion in the lungs of hydrogen and oxygen.lrO He claimed that water in pulmonary exhalations came from transpiration, not oxidative combustion.“’ He thought Lavoisier’s caloric theory was still so controversial an issue among physicists that it should not be applied

107. Ibid., p. 108. 108. Michael Gross, “Function and Structure,” chaps. 2 and 3. 109. Actually Lavoisier’s own views were more flexible. See J. S. Fruton,

Molecules and Life (New York: John Wiley, 1972), p. 264. 110. FranGois Magendie, “Experiences pour servir ri l’histoire de la transpira-

tion pulmonaire,“BuZl. Sot. Philomat., 2 (1811), 252. 111. Albury, “Bichat and Magendie,” p. 130n294.


prematurely to the problem of animal heat.l12 In his 1809 essay, he scarcely made mention of the work of contemporary chemists, except to say that “no analogy, not even a probable one, has yet been found between the play of ordinary chemical affinities and the nutritive movement.” 113 Likewise, the molecular movements responsible for vital action “cannot at this moment he compared to those which occur within inert bodies.” *14 Moreover, “it is impossible at the present time to conceive that this phenomenon could be produced by the general laws of nature.““* Thus, even when Magendie undertook his later studies of nonnitrogenous diets, while he drew upon knowledge of elementary composition of organic materials, his approach was that of traditional physiology and pathological anatomy and his conclusions were irrelevant to the structure-forming aspect of nutrition. Magendie’s interest was of course engaged by the practical concerns of the Acade- mie, leading for instance to studies of the nutritive value of gelatin. But the proximate source for his initial conception of nutrition and its significance in the overall pattern of physiological thought can be more precisely specified, and the explicit evidence points to Cuvier as the mediator of Magendie’s early views on nutrition and metabolism.

Perhaps, then, it is Cuvier who interpreted for physiology the significance of the new chemistry. However, as indicated above, Cuvier’s approach shares with earlier zoologists writing even before Lavoisier’s time an interest in metabolic processes responsible for the formation and maintenance of organic structure, although he drew back from the sort of facile identifications Lamarck had made between such processes and the operations of physical agents like caloric. Indeed, one of the most striking aspects of Cuvier’s comments on chemistry and metabolism is not his emphasis on the achievements of the new chemistry but, rather, his perception that these achievements were irrelevant to the fundamental problems of physiology as he perceived them. This is not obvious, however, from his observation that “the chemical part of the problem” of life had been “almost completely” resolved.116 That had to do with composition, that is, with “what matters beings attract, and what they reject from themselves. “11’ Yet his satisfaction with the

112. Magendie, “Quelques idles,” p. 108. 113. Ibid., p. 110. 114. Ibid., p. 109. 115. Ibid. 116. Cuvier, Rapport historique, p. 189. 117. He also accepted the general contrast between chemical inputs and

outputs of plants and animals which had been developed by Lavoisier, Crell, de

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solution of “the chemical part of the problem” left a wide berth for nonchemical problems: according to Cuvier, the largest lacunae remained in the study of “the dynamic, or properly physiological, part” of the problem of life, that is, the “forces” by which nutritive matters are attracted, retained, directed, and expelled, 118 or how the “distribu- tion of elementary materials of living bodies in their diverse parts occurs” throughout the formation of “what one calls secretions.” But despite the achievements of the chemists, the understanding of secretions had made little progress:

Of their mechanism, still only very obscure ideas have been advanced: some suppose for each secretion a kind of sieve; others, some tissue which attracts by way of affinity; there are some who, with more reason, have the whole system of vital forces cooperate in it. What one may say in general is that secretion is connected to the primitive form of each organ. Each organ has, for its part, like the whole body, the power to attract and reject substances which are brought to it, according to whether they agree with its nature. One thus may do for each organ what is done for the whole body. One may examine, for example, what enters the liver, what leaves it, and what remains there; but it is understandable that here it would be necessary to know with rigor not only the general composition of animal principles, but the particular proportion of each separate principle; and we have seen above that, in these minute differences, chemistry abandons us.l19

In discussing nutrition, the deposit that the blood makes of new molecules to enlarge or support the solids,” Cuvier saw it as the object of “grand researches,” i20 but these were not done by chemists. Instead, he cited the studies of Scarpa on bones, and of Hunter, Blake, Tenon, and himself on teeth.121 And so, interestingly enough, did Magendie.a year later when he commented that the tendency of organisms to take

Saussure, Sennebier, Spallanzani, Vauquelin, and Hall6 (ibid., pp. 189-193). He praised the new capacity of chemistry “to transform at its pleasure a host of immediate principles into one another” so that “these same animal and vegetable acids which also result from the concurrence of vital forces are formed at will” by the chemist (pp. 118-119).

118. Ibid., p. 189. 119. Ibid., pp. 193-194 (my emphasis). 120. Ibid., p. 240. 121. Ibid., p. 230-233.

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up alimentary substances for a definite period of time only, and “the results of experiments on the coloring of bones and some other analogous experiments, are all the positive knowledge we have on nutrition.” rz2 Finally, after stating his conviction that embryonic development is epigenetic (or characterized by differentiation and organ formation) rather than preformed (or dependent merely upon enlarge- ment of preexisting structures in the egg), Cuvier noted that “the general theory of organized beings remains still, as we have said, the most profound mystery of the natural sciences.“rz3

To sum up, Cuvier and Magendie strongly emphasized metabolic processes, especially nutritive processes related to the development and maintenance of organic structure. But they did so as the heirs of a relatively long-standing interest of zoologists rather than because the analytical achievements of the new chemistry had persuaded them of its efficacy in treating the main problems of physiology. While they interpreted nutritive metabolism as a problem in the rapprochement between anatomy and forces on the order of chemical attraction, they saw chemistry having as yet made no inroads. Instead of simply ack- nowledging methodological problems, they anticipated new laws which transcended those of existing physical and chemical theory.

Still, the physical sciences may have offered some inspiration. Beyond the phenomena of life which physics and chemistry may explain lie unknown elements, Cuvier wrote in 1806, which must be analyzed for what they share in common, the end point of such analysis being “the laws which must be attributed to this common principle if it is found that one exists.“lz4 Magendie in 1816 anticipated the genius who would “discover the laws of the vital force, as Newton made known to us the laws of attraction.” iz5 They envisioned not necessarily a fully physicochemical analysis of living organisms but laws of life as deterministic as were existing physical laws. Ultimately, they bore witness to a faith in the possibility of the sort of deterministic control the physical sciences had so dramatically achieved over the apparent variability and unpredictability of their subject matter.

Small wonder that their actual work focused on the central nervous system, and that their psychological doctrines reduced ambiguous emtions to clear concept formation. For the nervous system did give the researcher some definite control over actions or expressions he

122. Magendie, “Quelques idles,” p. 109. 123. Cuvier, Rapport historique, pp. 239-240. 124. Cited in Abury, “Bichat and Magendie,” p. 106. 125. Magendie, Elementary Compendium, p. 9.

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could elicit or eliminate by stimulating or destroying its parts. So, too, Magendie’s observation on the uncertainties of internal sensations aptly illustrates the ramifications of such deterministic thinking: “generally [such thoughts] are vague, confused, and frequently we know not even what they are; they are always more or less fugitive.” lz6 Viewing emotions as ideas suggested that rational process could determine them as well.

CONCLUSION

Overall, the transformation described here represents a changed relationship among physiological functions and a corresponding shift in their anatomical localization. Within two decades, a generalized and diffused conception of sensibility and contractility gave way. No longer viewed as properties which could account for an array of processes besides feeling and moving, sensibility and contractility became identified exclusively with perceived feeling and observable motion. This limitation in the purview of sensibility and contractility as functions was embodied in a corresponding anatomical localization: no longer all the tissues, but now only the neuromuscular system, manifested sensibility and contractility. A property spread through the whole organism had been located in discrete parts. This functional distinction and localization persisted as a basis for physiological research at least throughout the remainder of the century.12’ The isolation of feeling as a central nervous phenomenon included 2 subtler shift. Feelings and emotions - previously interpreted as seated in such viscera as the heart, stomach, gut - came now to be primarily mental and even intellectual events situated in the brain: emotions became a species of ideas.

This transformation in physiology was not the direct result of either new research findings or the adoption of an experimental methodology. Nor was it simply a consequence of the reductionistic dependency of a branch of biology on the physical sciences. Rather the change reflects, more immediately, the resolution of a schism within biology over conflicting theoretical and investigative priorities, in which attitudes and assumptions of one subdiscipline, supported by the power and

126. Ibid., p. 80. 127. See Gross, “Function and Structure,” Appendix I; Young, Mind, Bruin,

and Adupfution, p. 94; and “Recent Discoveries on the Physiology of the Nervous System,“Edinburgh Med. Surg. J., 21 (1823), 142-143.

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prestige of a renowned scientific institution, supplanted the contrasting principles of another.

Acknowledgment

At every stage of this project, Gerald Geison has offered more thorough, insightful, and patient advice than I have been able fully to profit from.

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