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Richet, Charles Robert


(b. Paris, France, 26 August 1850; d. Paris, 3 December 1935)

physiology, psychology.

Richet was the son of Alfred Richet, a distinguished surgeon. While attending the Lycée Bonaparte, he was undecided whether to devote himself to literature or to science. He entered medical school but was bored with anatomy and surgery, and wrote poetry and drama to divert himself. Serving as an intern in 1873, he was placed in charge of a female ward, where he witnessed a hypnotic experiment. Over the next two years he produced numerous hypnotic trances in his patients, publishing a summary of his experiences in 1875. The characteristic behavior of hypnotic subjects, he argued, could not be explained away as simulation. The basic phenomena of a hypnotic trance followed as regular a course as a disease. The more often a person is placed in a hypnotic state, Richet observed, the more distinct the hypnotic phenomena become.

Richet’s experience with hypnotism stimulated a lifelong interest in the associations between psychic and physiological phenomena, and helped persuade him to abandon a surgical career and turn to physiology. At the time he made that choice, physiology had passed through three decades of rapid, formative growth. Although debate over fundamental questions continued, the bulk of the research consisted of extensions and refinements of earlier investigations. Most of Richet’s early physiological work followed that pattern. While discovering little that was startling, he made significant contributions to knowledge of gastric digestion, the nature of muscle contractions, the toxic effects of inorganic salts, and the production and regulation of animal heat.

Richet entered physiology at a time when the center of experimental activity had shifted to Germany and when French scientists were complaining of the lack of adequate support. Nevertheless, he gained access to an extraordinarily rich scientific milieu. Between 1876 and 1882 he worked extensively in the laboratories of Jules Marey and of Marcelin Berthelot at the Collège de France, and of Alfred Vulpian at the Faculty of Medicine. He also made histological examinations in the laboratory of Charles Robin, and studied digestion in fish at a marine biological station directed by Paul Bert. Richet never worked under the direct supervision of Claude Bernard, yet Bernard probably exerted a decisive influence, especially in terms of general orientation. He was influenced especially by Bernard’s view of the relation between physiology and pathology, by his toxicological studies, and by his generalization that a poison introduced into the blood must act upon a specific tissue. Despite his switch from medicine to physiology, Richet continued to be involved in medical problems. In 1876 he served as assistant to the surgeon Aristide Verneuil. The work of Jean-Martin Charcot and others on hysteria and hypnotic therapy especially interested him. Richet seems to have been unusually suggestible; he absorbed ideas readily from those around him, and he eagerly followed up whatever was pointed out to him as a promising problem or approach. His familiarity with the literature of his field enabled hire frequently to locate important gaps in the knowledge of problems that had been extensively investigated, and to find ways to fill them.

Richet entered Marey’s laboratory primarily to learn the latter’s methods of graphically recording physiological phenomena. Although the use of revolving drums to record muscle movements and pressure changes had been developed in the laboratory of Carl Ludwig, Marey had devised the most precise and versatile recording devices. Richet quickly found ways to apply Marey’s recording methods in the context of his medical service. Recording the respiratory motions of tetanus patients, Richet showed that there were two forms of respiratory spasm: one occurred during inspiration, the other during expiration.

Verneuil recommended that for his doctoral dissertation Richet investigate the phenomena of traumatic pain. Richet began, in January 1876, by comparing the pain caused by electric stimulation of the healthy and affected sides of hemianesthetic hysteria patients; soon, however, he focused on the general function of sensory nerves. Utilizing frogs poisoned with strychnine, he demonstrated that sensory nerves deprived of their blood supply die gradually from the periphery toward the center. He measured the abnormal delay in the perception of an electric shock by ataxic patients, and showed that the lag was not proportional to the distance of the stimulus from the central nervous system. Subjecting normal humans to electrical stimuli, he found that stimuli too weak to be perceived if widely separated were felt if they were closer together. For equally spaced stimuli, the delay between their beginning and the first moment of perception was inversely proportional to the intensity. These effects were analogous to the known summation phenomena for muscle contractions.

In July 1876, Verneuil performed a gastric fistula operation on a young man named Marcelin R., whose esophagus had become blocked after he swallowed caustic potash. He urged Richet to use the opportunity to repeat William Beaumont’s famous experiments on digestion. Although there had been dramatic progress in the experimental study of gastric digestion over the intervening period, some of the main features of the process remained obscure and controversial. Uncertainty still remained over whether the gastric acid was hydrochloric, lactic, or some other, for analysts could not be sure which of the acids recoverable from the complex gastric juice was in a free state.

Richet undertook this research in the laboratory of Berthelot, who gave him assistance, including a new method to ascertain the nature of the gastric acid. In 1872 Berthelot and E. C. Jungfleisch had shown that the relative quantities of a solute distributed between equal volumes of two immiscible solvents are constant, which they called its “partition coefficient.” Berthelot advised Richet to mix an aqueous solution of gastric juice with ether. The high ratio of acid dissolved in water to that dissolved in ether indicated that the principal acid was a mineral acid and therefore undoubtedly hydrochloric. By an extension of the procedure Richet showed that an organic acid with a partition coefficient approaching that of an isomer of lactic acid forms during digestion, and suggested that the lactic acid derived from the fermentations of certain digesting aliments. This consideration led him to undertake experiments on the conditions affecting lactic fermentation, an investigation he pursued for many years.

At Bernard’s suggestion Richet next studied the gastric juice of fish, which he found to provide very favorable conditions for investigation. It was highly active, strongly acidic, and, unlike the juice of mammals, was secreted as a coherent, mucilaginous mass. With it he confirmed that there is more chloride than the quantity contained in the salts of the juice, thereby supporting the opinion that the principal acid is hydrochloric. When he mixed sodium acetate with the juice, however, he discovered by means of the partition coefficient method that less than half as much acetic acid formed as the same quantity of hydrochloric acid ought to displace from the salt. He inferred that hydrochloric acid does not exist free in gastric juice, but in combination with an organic substance that he guessed might be a derivative of protein. In 1878 he published a comprehensive memoir on the properties of gastric juice in which he reviewed all aspects of the digestive process and its variations in mammals, fish, and invertebrates. He gave reasons for the disagreements among previous authors over the identity of the acid, and argued that the partition coefficient method was best suited to resolve the question because it did not alter the gastric juice. He noted that in order to obtain pure gastric juice from Marcelin R., he had him chew highly flavored foods, which produced an abundant flow. Since the food could not have entered Marcelin’s stomach, Richet ascribed the secretion to a nervous reflex.

During 1878 Richet passed his agrégation examination and was named professeur agrégé at the Faculty of Medicine, where he began to work in the physiological laboratory directed by Vulpian. His first major investigation there was inspired mainly by Marey’s research on muscle contraction. The earliest graphic recordings of muscle contractions were made in 1850 by Hermann von Helmholtz, who analyzed the resulting curves into a latent period, a short period of rapid ascent, and a more gradual descent, measuring the time consumed in each phase. The relatively large mass of his recording mechanism, however, limited its accuracy. Many physiologists labored to refine his method and to determine the influence of varied conditions on the amplitude and time relations of the contractions. During the 1860’s Marey developed myographs that minimized the inertia of the system transmitting the muscle motions to the recording drum. He attained remarkably precise curves, distinguishing subtle differences in the characteristics of the movements according to the duration and intensity of the stimulus, and the condition of the muscle. Among the phenomena Marey helped to establish was that the extended contractions produced by direct electrical stimulations were composed of a series of brief “shocks,” which fused to form a tetanic contraction if the stimuli were repeated at short enough intervals. He and others carried out most of these investigations with the gastrocnemius muscle of the frog because it was readily available and simple to prepare, although they were aware that the responses of different muscles varied widely.

Richet decided that a detailed study of an invertebrate muscle might help to distinguish general properties of muscle contraction from peculiarities of individual types. He therefore applied the current analytical techniques to the claw and tail muscles of the crayfish. They reacted quite differently. The tail muscle produced brief, strong contractions, did not go into tetanus unless the stimuli were very frequent, and quickly became fatigued. The contractions of the claw were much longer, and repeated stimuli easily produced a persistent tetanus. The claw muscle exhibited with remarkable clarity the phenomenon of latent summation.

Conflicting measurements of the latent period by other physiologists led Richet to examine more closely the length of the period in the crayfish claw. The time turned out to be variable, the length increasing especially with fatigue. If, however, while the muscle was still in a contracted state from one stimulus, he gave it a second identical stimulus, the second latent period was shorter than the first. As in his earlier study of hypnosis, Richet was particularly interested in the way in which a physiological response to a given influence may be conditioned by prior exposure to that influence. He also noticed that the relaxation of a detached claw muscle, after a contraction produced by a strong stimulus, was divided into two distinct periods—a short, quick descent followed by a plateau period, which he called contracture. In 1880, using a fresh, lightly weighted muscle, Richet was able to evoke a more distinctly demarcated contractive phase, consisting of a second contraction without an additional stimulus. He called the phenomenon the “secondary wave.”

By 1883 Richet was well-established as an experimental physiologist and was directing students of his own. He also began to give the lectures in physiology at the Faculty of Medicine. For two years he concentrated his course on animal heat while carrying out experiments on the same topic. During the preceding decades attention had spread from the question of the source of animal heat to the problem of how warm-blooded animals can maintain a nearly constant temperature. Isidore Rosenthal, Eduard Pflüger and his students, Léon Fredericq, and others were seeking to answer experimentally such questions as what role changes in heat production and heat loss played in compensating for external changes; whether the stimulus to which such mechanisms respond is a peripheral reflex or a change in the internal temperature of the animal; and where the nervous center that coordinates this regulation is located. These problems had already been extensively investigated when Richet took them up; but the systems involved were so complex, and the conditions requiring investigation so extensive, that none of the questions had been conclusively answered.

The first question Richet treated was the role of the central nervous system in controlling temperature. Numerous observations by others had established that the temperature of a mammal rose when the cervical region of the spinal cord or the medulla oblongata was excited or injured. Richet and his two assistants, Eugene Gley and Pierre Rondeau, found in March 1884that they couldobtain the same effect by exciting the anterior lobe of the cerebral cortex of rabbits. This result, however, left Richet in the same dilemma that others had faced in analogous situations: Was the effect due to “a greater production of heat or a lessened loss at the periphery?” To resolve the question decisively, he realized, he would have to measure precisely the quantities of heat that the animals produced. After the pioneering studies of Lavoisier, and of Dulong and C. M. Despretz in the 1820’s, few direct calorimetric measurements had been made; physiologists usually calculated the output indirectly from the products of respiratory combustion. In May 1884 Richet thought of constructing a very sensitive calorimeter in which the heat formed within a chamber would expand the air in a closed surrounding chamber, forcing a corresponding volume of water to overflow from the open end of a siphon connected with the air chamber. After calibrating the apparatus, he could measure the heat produced by the quantity of water collected. At almost the same time Arsène d’Arsonval also invented a calorimeter that utilized the expansion of air, but with a different measuring method. From d’Arsonval, Richet received several suggestions for his own instrument.

Meanwhile Richet showed that the characteristic rapid breathing of dogs was a cooling device, increasing the heat loss by evaporation of moisture from the tongue. In 1887 he demonstrated that the process was not a means to increase the respiratory gaseous exchanges; it could, in fact, take place only under conditions in which the dogs did not require immediate normal respiration—that is, when the blood was low in carbonic acid and saturated with oxygen. For this reason he named the effect thermal polypnea. Although thermal polypnea is a specialized adaptation in animals that do not perspire through their skins, it provided a very convenient means for elucidating the general character of temperatureregulating mechanisms, because its occurrence was directly observable.

By November 1884, Richet had perfected his siphon calorimeter. With it he demonstrated that the lesions of the cerebral cortex of rabbits that caused their temperatures to rise always produced a substantial increase in the heat evolved. These experiments led him to believe that changes in heat production were more important than vasomotor control of heat losses in regulating the general temperature of animals. His work also provided strong evidence for the involvement of the higher centers of the brain in the control of heat production.

Richet took advantage of his new calorimeter to examine the effects of other conditions on the heat output of animals. The most important factor, he found, was size. For rabbits, dogs, and guinea pigs he established that the larger the animal, the less heat it produced per unit weight. This was not a surprising result—Carl Bergmann had predicted it in 1848 on the basis of the mathematical relation between surface and volume—but it was a satisfying verification of the conformity of animals to physical principles. Calculating the surface area of the animals tested from their weights, by means of the simplifying assumption that they were approximately spherical, Richet demonstrated that their heat production was nearly proportional to their surface areas. In Germany, Max Rubner established the same relationship independently, using different methods.

Between 1887 and 1891 Richet extended his investigations of animal heat. He supported his view that thermal polypnea takes place only when the carbonic acid concentration of the blood is low, by showing that the breathing of a mixture of oxygen and carbon dioxide precludes its appearance. He confirmed his law of the proportionality of heat and surface area for several mammals, using the indirect method of measuring heat production by the quantity of carbon dioxide exhaled. In 1889 Richet showed that dogs anesthetized by chloral no longer produced heat in proportion to their surface area, from which he inferred that the different rates of heat production normally maintained by animals of different sizes must depend on the control of the central nervous system. Nevertheless, he reasoned, the great difference between the heat output of large and small animals must derive from differences in the rates of activity of muscle tissue—that explained why large dogs tend to be lethargic, whereas small ones are continually active and shiver frequently. The last observation led him to investigate shivering as a means of thermal regulation; he regarded it as the mechanism that compensates for coldness in the same way that polypnea compensates for heat. Like polypnea, he showed, shivering can be brought on either by a peripheral reflex or by a direct action on the central nervous system. To demonstrate the latter he anesthetized dogs with chloral. The internal temperatures of the animals gradually decreased, until at a certain point the animals characteristically began to shiver. As soon as that happened, their temperatures started to rise. The heat production in the chloralized dogs was much less than normal, but returned almost to normal when they shivered.

The research by Richet described so far dealt mostly with what had already become classical problems in physiology. Closely attuned to current trends, he reflected in his diversified investigations a representative cross section of the dominant concerns of that maturing science. Increasingly after 1880, however, his work was influenced by the spreading evidence of the pervasive biological effects of microorganisms. These phenomena apparently first impinged on his activities in 1877, when a critic remarked that the organic acids found during his artificial digestion experiments were probably produced by bacteria in the gastric juice. Richet accepted this criticism but replied that bacteria must also be present in the stomach, so that the phenomenon probably occurred physiologically. Soon afterward he was able to find a few bacteria in the stomachs of fish. In 1882 and 1883 he discovered Bacillus and other types of motile bacteria in the peritoneal fluid, blood, and lymph of fish, and in the fluids of marine invertebrates. Using a medium of sterile beef bouillon, he and Louis Olivier succeeded in developing cultures from some of them. In 1881 Richet examined the transformation of urea to ammonium carbonate that he observed in the stomachs of dogs rendered uremic, and ascribed the reaction to the organized ferment discovered by Louis Pasteur. These studies involved the methods Pasteur had developed for growing pure cultures of specific microorganisms in suitable nutrient media. It was, therefore, probably in order to learn those methods that Richet carried out some of these investigations in the laboratory of Philippe van Tieghem, a former student of Pasteur’s who had helped to perfect the techniques.

The event that was decisive in drawing Richet into the new field was Pasteur’s announcement, in February 1880, that he had discovered a way to immunize chickens against the fatal fowl cholera by inoculating them with attenuated microbes cultured in a broth made from chicken muscle. Pasteur brought some of his preparations of the fowl cholera microbes to Vulpian’s laboratory. Richet, who watched him demonstrate there, was deeply impressed. He was particularly attracted to the idea that the microbes might secrete a Chemical toxin that caused the disease, and that there might also be a chemical substance opposing the toxin in immune animals. During his physiology course in 1881 he mentioned an observation by Auguste Chauveau that Algerian sheep are resistant to anthrax, whereas French sheep are susceptible to it. Richet proposed the hypothesis that the difference might arise from some extractive substance in the blood of the Algerian variety. That idea suggested to him that he might be able to protect animals vulnerable to a disease by giving them transfusions of blood from resistant animals. He was not able to follow up this plan, however, for several years.

In 1888 Richet and Jules Héricourt discovered a new type of staphylococcus bacterium in an epithelial tumor of a dog. Adopting the strategy that had become standard since Pasteur’s investigation of fowl cholera, they grew a pure culture of the bacteria. Rabbits inoculated from the culture died, but in dogs the injection produced only a large abscess. This difference paralleled what Pasteur had found for the fowl cholera microbe, which caused the death of chickens but left guinea pigs healthy except for an abscess that contained the microorganisms. Still following Pasteur’s methods, Richet and Hericourt attenuated the new microbe by cultivating it for several days or at a temperature above the optimum for its growth. Rabbits vaccinated with the attenuated microorganisms became immune to inoculations with the virulent form. Recalling Richet’s earlier speculation that the blood of resistant animals might contain some special substance, they now sought to attain the same result in another way, by transfusing blood from dogs into rabbits. When injected directly into a vein, the dog’s blood was toxic to the rabbits; but they obviated this difficulty by transfusing instead into the peritoneal cavity, from which the blood was gradually absorbed. Transfusions made from dogs that had previously been inoculated with the staphylococcus conferred immunity on the rabbits.

Following this success, Richet and Héricourt attempted to apply their new principle of “hemotherapy” to tuberculosis. They were able to retard the progress of the disease in rabbits by transfusing dog’s blood, but were unable to prevent the death of the rabbits. Nevertheless, in December 1890 they transfused dog blood serum into a human tuberculosis patient, again attaining only a delay in the course of the disease. By inoculating dogs with bacilli of avian tuberculosis, a form of disease against which the dogs were resistant, they were able to make them immune to human tuberculosis, to which they normally were sensitive. Next they transfused blood from dogs vaccinated in this way into dogs infected with human tuberculosis and were able to slow, sometimes to arrest, the disease. Despite these hopeful effects, their goal of developing an effective vaccine for human use eluded them. They were also unsuccessful in their attempts to apply serum therapy to human cancer.

After his hopes for serum therapy in tuberculosis had been disappointed, Richet turned to dietary factors, long known to have some effect. In 1899 he found that a diet of raw meat brought about a remarkable improvement in the physical condition of tubercular dogs. In 1900 he determined that the effect was due principally to “muscle plasma,” that is the fluids extracted from meat. He ascribed the result not to the alimentary value of the plasma but to some kind of immunizing action, and called the method of treatment “zomotherapy.” For many years he urged its application to human tuberculosis.

By 1900 Richet had completed a quarter-century of fruitful, prolific experimental activity. He had attained an eminent professional position, having been named to the chair of physiology at the Faculty of Medicine in 1887, and had attracted many able students. His resourceful research had contributed substantially to several important areas of physiology and to a new field of medicine; but he had made few discoveries that strayed beyond the bounds of the normal development of these fields. Most of his investigations were typical of a large, well-organized science; that is, they clustered around the fundamental work of other men. In the first decade of the twentieth century, when he had passed his fiftieth year, Richet finally entered the charmed circle of scientists who have discovered major unexpected phenomena.

The investigations from which Richet’s principles of hemotherapy and zomotherapy emerged involved him in subsidiary toxicological problems. In 1889 he was confronted with the fact that the blood of one animal species is toxic to another. In 1900 he found that muscle plasma was toxic if injected directly into a vein. During the following year he tried to establish the toxic dose of muscle plasma for dogs, defined as the quantity per kilogram of the animal that would cause it eventually to die. His approach resembled efforts he had made twenty years earlier to define toxic doses of various metallic salts. Later in the year, as a member of a scientific expedition on the yacht of Prince Albert of Monaco, he had an unforeseen opportunity to utilize his toxicological experience. The prince and another scientist on the voyage advised him to study the toxic properties of the tentacles of the Portuguese man-of-war. While still on board, Richet and Paul Portier established that an aqueous or glycerin extract of the tentacles was extremely toxic. After returning to France, Richet decided to compare the properties of the poison with those of the poison obtainable from members of another class of coelenterates, the sea anemones. The effects of a glycerin extract of this toxin were similar to that from the Portuguese man-of-war. in his customary manner he set out with Portier to determine the toxic dose. They began by giving intravenous injections to a large number of dogs, in doses ranging from 0.05 to over 0.30 cc. of the extract per kilogram of the recipient. Those that received more than.30 cc. died after four or five days. Richet and Portier kept the surviving dogs in order to use them again for a similar experiment after they had recovered. When they reinjected these animals two to three weeks later, all those receiving doses of 0.08 to 0.25 cc. quickly died. This extraordinary outcome led them to reflect that the poison must have properties that are the opposite of the immunizing properties of serums, attenuated bacterial cultures, and other toxins. Instead of reinforcing the resistance of an animal to later injections, a sublethal dose diminished it. For this reason they called the property anaphylactic (“contrary to protection”). On 15 February 1902 they demonstrated the effect at a meeting of the Société de Biologic by injecting two dogs, one of which had been injected previously.

Richet and Portier next pursued the question of how long the anaphylactic effect of the poison would last, and found that the condition persisted for at least two and a half months. In 1904 and 1905 Richet observed effects lasting, with gradually diminishing intensity, for nearly eight months. The complexity of the symptoms of the anaphylactic animals led him and Portier, however, to suspect that the toxin contained several active substances. With the collaboration of Auguste Perret they were able, by February 1903, to isolate from the poison a whitish powder that reproduced most of the effects of the original glycerin extract. Because of the strong action on the vasomotor system, they called the substance congestin. During the next two years Richet refined the experiments, using a purer, more potent form of congestin and repeating with rabbits the results he had obtained with dogs. Suspecting from the beginning that many other poisons would produce analogous actions, he now began to study other cases. In 1905 he obtained an increased sensitivity by repeated injections of morphine, and in 1907 he extracted from mussels a poison similar in its effects to congestin. Meanwhile other investigators were finding that nontoxic albuminous substances, such as blood serum, could also cause anaphylactic phenomena. Inoculations of bacteria produced highly specific anaphylactic reactions to further inoculations with the same microbe. The anaphylactic response to blood serum turned out also to be specific for the species of the donor animal. Thus anaphylaxis was soon revealed to be a phenomenon of broad scope with potentially crucial consequences for medical practice.

In 1907 Richet began to construct a general theory of anaphylaxis based on his accumulating observations and those of his colleagues. The opposite, yet obviously analogous, effects of anaphylactic and immunizing toxins induced him to envision mechanisms patterned after the concepts of antigenantibody interactions that Paul Ehrlich, Jules Bordet, and others had proposed to explain immunization. Reasoning along lines similar to theirs and also to the reasoning that he had followed a decade earlier when he transferred immunity by transferring the blood of a resistant animal, Richet inferred that some special substance must form in the blood of anaphylactic animals and must react with the toxin later injected. He confirmed this surmise when he was able to make dogs anaphylactic by injecting them with serum from an anaphylactic animal. The heightened sensitivity of an anaphylactic animal, he concluded, must derive from the presence within it of a substance that is not toxic but that reacts with a toxin such as congestin to produce a third, highly toxic substance. He designated the first and last of these substances “toxogenin” and “apotoxine,” respectively. An anaphylactic poison, he asserted, produces a true disease. The temperature changes and denutrition that follow an injection of congestin are entirely equivalent to the evolution of a microbial infection. A better way to put it, he thought, was that a disease is really a slow intoxication in which the toxin is produced within the animal by the microbes and then provokes the formation of an immediately toxic substance.

The fact that anaphylaxis appeared to be a reaction harmful to the animal itself must have posed an awkward dilemma for Richet, who had often stressed that all physiological actions help to conserve the life of the organism. In some of his 1907 experiments he found that the anaphylactic period was followed by one of relative immunity, so that he was able to view the phenomena as an “admirable adaptation,” in which anaphylaxis hastens the defensive reaction of an animal to feeble doses of microbial poisons. In subsequent experiments this effect did not appear consistently, however, so he was forced to try to reconcile anaphylaxis with biological finalism in a broader sense. He admitted that, on the whole, the defense of the organism must be weakened when its sensitivity to poisoning is augmented; but he claimed that the violent reaction that is harmful to the individual is essential to protect the stability of the species. If the albuminoid substances of other species that produce anaphylactic responses were permitted to penetrate repeatedly into the blood and tissues and remained there, the chemical identity of the species would be endangered; the somatic constitution acquired by natural selection would be continually at the mercy of accidental circumstances. That these explanations were teleological did not embarrass Richet; despite his faith in the physicochemical foundation of physiological phenomena, he also reiterated frequently that the teleological view “must always serve as a guideline in every biological doctrine.”

In 1911 Richet reviewed the development of research on anaphylaxis in a monograph in which he assimilated the work of other investigators into the framework set by his own. He could already claim with justification that “the domain of anaphylaxis is very vast,” and he could realistically portray that domain as emerging principally from his discovery. By 1913 its scope had become well enough recognized so that Richet was awarded a Nobel prize for his part in it.

Richet had many interests beyond physiological research and writing. Attracted to aviation through Marey’s experiments on bird flight, he participated in the design and construction of one of the first airplanes to leave the ground under its own power. Through friends he became interested in spiritualistic phenomena, coming to believe that true premonitions sometimes occurred, and exerted a formative influence on the early development of what he called metapsychics. Richet was a dedicated pacifist and wrote a number of general history books in order to demonstrate the malevolent effects of war. He also composed poetry, novels, and drama.

Richet continued his research on anaphylaxis, lactic acid fermentation, zomotherapy, and other subjects after 1913. He spent part of World War I at the front investigating problems in the transfusion of blood plasma. In 1926 he received the Cross of the Legion of Honor.


I. Original Works. Books by Richet include Rcherhes expérimentales et cliniques sur la sensibilité (Paris , 1877); Des circonolutins Cérébrales (Paris, 1878), translated by E. Fowler as Physiology and History of the Cerebral Convolutions (New York, 1879); Du sue gastrique chez l’homme et les animaux (Paris, 1878); Physiologic des muscles et des nerfs (Paris, 1882); L’homme et l’intelligence: Fragments de physiologie et de psychologie (Paris, 1884); La chaleur animale (Paris, 1889); Essai de psychologie générale, 2nd ed. (Paris, 1891); Dictionnaire de physiologic, 10 vols. (Paris, 1895–1928), with the collaboration of P. Langlois, L. Lapicque, et al.; L’anaphylaxie (Paris, 1911); Traité de métapsychique (Paris, 1922); La nouvelle zômothérapie (Paris, 1924); L’intelligence et l’homme (Paris, 1927); and L’avenir et la prémonition (Paris, 1931).

Among Richet’s most significant research articles are “Du somnambulisme provoqué,” in Journal de l’anatomie et de la physiologie normales et pathologiques de l’hormne et des animaux, 11 (1875), 348–378; “Des propriétés chimiques et physiologiques du suc gastrique,” Ibid., 14 (1878), 170–333; “Contribution à la physiologic des centres nerveux et des muscles de l’écrevisse,” in Archives de physiologic normale et pathologique, 2nd ser., 6 (1879), 262–284, 522–576; “Étude sur l’action physiologique comparée des chlorures alcalins,” Ibid., 2nd ser., 10 (1882), 115–174, 366–387; “Recherches de calorimétric,” Ibid., 3rd. ser., 6 (1885), 237–291, 450–497; “Des conditions de la polypnée thermique,” in Comptes rendus … de l’Académie des sciences, 105 (1887), 313–316; “Sur un microbe pyogène et septique et sur la vaccination contre ses effets,” Ibid., 107 (1888), 690–692, written with J. Héricourt; “De la transfusion péritonéale, et de l’immunité qu’elle confère,” ibid., 748–750, written with Héricourt; “Le frisson comme appareil de régulation thermique,” in Archives de physiologie, 5th ser., 5 (1893), 312–326; “De la formation d’urée dans le foie après la mort,” in Comptes rendus … de l’Académie des sciences, 118 (1894), 1125–1128; “Du traitement de l’infection tuberculeuse par le plasma musculaire, ou zômothérapie,” Ibid., 130 (1900), 605–609, written with Héricourt; “De l’action anaphylactique de certains venins,” in Comptes rendus de la Société de Biologie, 54 (1902), 170–172, written with P. Portier; “De l’anaphylaxie en général et de l’anaphylaxie par le mytilo-congestine en particulier,” in Annales de l’Institut Pasteur, 21 (1907), 497–524; “De l’anaphylaxie et des toxogénines,” Ibid., 22 (1908), 465–495. The chronological evolution of his research can most easily be followed through the many short notes he published in Comptes rendus de la Société de Biologie.

Biographical material for this article is based mostly on an autobiographical essay in L. R. Grote, ed., Die Medizin der Gegenwart in Selbstdarstellungen, VII (Leipzig, 1928), 185–220, and Richet’s L’oeuvre de Pasteur (Paris, 1923).

II. Secondary Literature. See Jean-Louis Fauré, “Discours: Funérailles de Charles Richet,” in Notices et discours. Académic des sciences, 1 (1937), 626–633; Marilisa Juri, Charles Richet physiologiste (1850–1935), which is no. 34 of Zürcher Medizingeschichtliche Abhandlungen, E. H. Ackerknecht, ed. (Zurich, 1965); André Mayer, “Notice nécrologique sur M. Charles Richet (1850–1935),” in Bulletin de l’Académie de médecine, 115 (1936), 51–64; Paul Painlevé, “Charles Richet et l’aviation,” in A Charles Richet: Ses ands, ses collègues, ses élèves (Paris, 1926), 61–63; A. Pi-Suner, “Charles Richet et la physiologic interfonctionnelle,” Ibid., 68–72; and F. Saint Girons, “Charles Richet (1850–1935),” in Revue générale des sciences pures et appliquées (1935), 677–679, with portrait. There are also obituaries in Nature, 136 (1935), 1017–1018; Proceedings of the Royal Society of Edinburgh, 56 (1935), 276 278; and Revue métapsychique, 17 (1936), 1–42.

Frederic L. Holmes

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Richet, Charles (1850-1935)

Richet, Charles (1850-1935)

Pioneer psychical researcher, honored professor of physiology at the Faculty of Medicine in Paris, and winner of the 1913 Nobel Prize in Physiology and Medicine. He was also the honorary president of La Societé Universelle d'études Psychiques, president of the Institut Métapsychique Internationale, and president of the Society for Psychical Research, London(1905). Richet was born on August 26, 1850, and educated at the University of Paris. He had an initial personal experience in lucidity (paranormal knowledge) in 1872. He confessed that although it had tremendous effect on him, he lacked the requisite intellectual courage to draw conclusions. In 1875, while yet a student, he demonstrated that the hypnotic state was a purely physiological phenomenon which had nothing to do with "magnetic fluids." "Following my article," he wrote of the result, "many experiments were widely made, and animal magnetism ceased to be an occult science."

A few years later, he published his studies in multiple personality. He sat with various mediums, including William Eglinton and Elizabeth d'Esperance, and in 1886-87 conducted many experiments in cryptesthesia with four subjects Alice, Claire, Eugenie, and Leontine. Some were in a hypnotic, some in a waking state. They reproduced drawings enclosed in sealed envelopes. As a result of these experiments Richet formulated the theory of cryptesthesia in these words: "In certain persons, at certain times, there exists a faculty of cognition which has no relation to our normal means of knowledge."

He founded with Dr. Dariex the Annales des Sciences Psychiques in 1890, and two years later he took part in the investigation conducted by the Milan Commission with the medium Eusapia Palladino. The report admitted the reality of puzzling phenomena, expressing also the conviction that the results obtained in light, and many of those obtained in darkness, could not have been produced by trickery of any kind.

Richet did not sign the report and in his notes on it in the Annales des Sciences Psychiques carefully stated his conclusions as follows:

"Absurd and unsatisfactory though they were, it seems to me very difficult to attribute the phenomena produced to deception, conscious or unconscious, or to a series of deceptions. Nevertheless, conclusive and indisputable proof that there was no fraud on Eusapia's part, or illusion on our part, is wanting: we must therefore renew our efforts to obtain such proof."

He became convinced of the reality of materialization phenomena by his experiments with the medium Marthe Béraud (better known as Eva C. ) at the Villa Carmen, Algiers, in General Noel's house. His report, published in the Annales des Sciences Psychiques (April 1906) aroused wide attention. He confirmed his experiments in later sittings at the house of Juliette Bisson and at the Institut Métapsychique of which, after the resignation of Professor Santoliquido, he was elected president. He was unable to detect Eva C.'s fraud which was conclusively revealed only in the 1950s.

He conducted experiments with a number of different mediums including Franek Kluski, Jan Guzyk, and Stephen Ossowiecki, both in Paris and Warsaw.

His book Traité de Métapsychique (1922; translated as Thirty Years of Psychical Research, 1923) summed up the experiences of a lifetime. The book was dedicated to Sir William Crookes and F. W. H. Myers. It became a sign of repentance for his earlier skepticism. He stated in his work:

"The idolatry of current ideas was so dominant at that time that no pains were taken either to verify or to refute Crookes' statements. Men were content to ridicule them, and I avow with shame that I was among the wilfully blind. Instead of admiring the heroism of a recognized man of science who dared then, in 1872, to say that there really are phantoms that can be photographed and whose heart beats can be heard, I laughed."

He accepted cryptesthesia, telekinesis, ectoplasm, materializations, and premonitions as abundantly proved. On the other hand, he considered doubtful apports, levitations, and the phenomena of the double, which he had no opportunity to examine thoroughly. He was most emphatic in stating: "The fact that intelligent forces are projected from an organism that can act mechanically, can move objects and make sounds, is a phenomenon as certainly established as any fact in physics." As if to leave a loophole for more definite proofs on psychic photography, direct writing, apports, psychic music, and luminous phenomena he added, somewhat naively: "No one would have thought of simulating them if they had never really occurred. I do not hesitate to think them fairly probable, but they are not proven."

His struggle with the problem of survival was very interesting. He stated: "I admit that there are some very puzzling cases that tend to make one admit the survival of human personalitythe cases of Leonora E. Piper 's George Pelham, of Raymond Lodge and some others."

His basis for disbelief in survival was twofold: first, the human mind has mysterious faculties of cognition; second these mysterious cognitions have an invincible tendency to group themselves around a new personality. He explained:

"The doctrine of survival seems to me to involve so many impossibilities, while that of an intensive cryptesthesia is (relatively) so easy to admit that I do not hesitate at all. I go so far as to claimat the risk of being confounded by some new and unforeseen discoverythat subjective metapsychics will always be radically incapable of proving survival. Even if a new case even more astounding than that of George Pelham were to appear, I should prefer to suppose an extreme perfection of transcendental cognitions giving a great multiplicity of notions grouping themselves round the imaginary centre of a factitious personality, than to suppose that this centre is a real personalitythe surviving soul, the will and consciousness of a self that has disappeared, a self which depended on a brain now reduced to dust.

"But except in a few rare cases, the inconsistency between the past and the present mentality is so great that in the immense majority of spiritist experiences it is impossible to admit survival, even as a very tentative hypothesis. I could more easily admit a non-human intelligence, distinct from both medium and discarnate, than the mental survival of the latter." Treating of the so-called death bed meeting cases he stated: "Among all the facts adduced to prove survival, these even seem to me to be the most disquieting."

He did not accept the facts of materialization as proof of survival.

"The case of George Pelham, though there was no materialization, is vastly more evidential for survival than all the materializations yet known. I do not even see how decisive proof could be given. Even if (which is not the case) a form identical with that of a deceased person could be photographed I should not understand how an individual two hundred years dead, whose body has become a skeleton, could live again with this vanished body any more than with any other material form."

He called the phenomena of materialization absurd, yet true, and explained:

"Spiritualists have blamed me for using this word 'absurd'; and have not been able to understand that to admit the reality of these phenomena was to me an actual pain; but to ask a physiologist, a physicist, or a chemist to admit that a form that has a circulation of blood, warmth, and muscles, that exhales carbonic acid, has weight, speaks, and thinks, can issue from a human body is to ask of him an intellectual effort that is really painful."

In concluding his weighty Thirty Years of Psychical Research, he was assailed by doubts:

"Truth to telland one must be as cautious in denial as in assertionsome facts tend to make us believe strongly in the survival of vanished personalities. Why should mediums, even when they have read no spiritualist books, and are unacquainted with spiritualist doctrines, proceed at once to personify some deceased person or other? Why does the new personality affirm itself so persistently, so energetically, and sometimes with so much verisimilitude? Why does it separate itself so sharply from the personality of the medium? All the words of powerful mediums are pregnant, so to say, with the theory of survival? These are semblances, perhaps, but why should the semblances be there?" Then, again, as if repenting his doubts, he explained:

"Mysterious beings, angels or demons, existences devoid of form, or spirits, which now and then seek to intervene in our lives, who can by means, entirely unknown, mould matter at will, who direct some of our thoughts and participate in some of our destinies, and who, to make themselves known (which they could not otherwise do) assume the bodily and psychological aspect of vanished human personalitiesall this is a simple manner of expressing and understanding the greater part of the metapsychic phenomena."

His next book, Notre Sixième Sens (1927; translated as Our Sixth Sense, 1929), was a courageous attempt to grapple with the problem of cryptesthesia. He conceived it physiologically as a new sixth sense which is sensitive to what he called the vibrations of reality. It is a sweeping theory that, in its implications, is nearly as far-reaching as the spirit theory.

In La Grande Espérance (1933), following an important monograph, L'Avenir et la Premonition (1931), he himself admitted that this vibratory theory is far from being sufficient for "there are cases in which á la rigeur one could suppose the intervention of a foreign intelligence."

These were the cases of veridical hallucinations. Even there he would have preferred to fall back on the vibratory explanation but for the puzzle of collective veridical hallucinations in which "one is almost compelled to admit the objective reality of the phantom." That admission did not allow him to doubt that "in cases of simple veridical hallucinations there is an objective reality as well." Pursuing this line of reasoning, he stated: "It appears that in certain cases phantoms are also inhabiting a house. I hesitate to write this down. It is so extraordinary that my pen almost refuses to write but just the same it is true."

Still, after having analyzed the purely psychological phenomena, if the choice was between the spirit hypothesis and a prodigious lucidity he would lean towards the second. For that explained all cases, whereas the former, although it is the better one in a small number of cases, was inadmissible in many others.

The grand hope of humanity lay in psychical research, in that immense incertitude which we feel in face of its extraordinary, truly absurd phenomena.

"The more I reflect and weigh in my mind these materializations, hauntings, marvelous lucidity, apports, xenoglossie, apparitions and, above all, premonitions, the more I am persuaded that we know absolutely nothing of the universe which surrounds us. We live in a sort of dream and have not yet understood anything of the agitations and tumults of this dream.

"Everything came down to this: "Either the human intelligence is capable of working miracles. I call miracles the phantoms, ectoplasm, lucidity, premonitions. Or assisting in our doings, controlling our thoughts, writing by our hand, or speaking by our voice there are, inter-blending with our life, mysterious, invisible entities, angels or demons, perhaps the souls of the dead, as the spiritualists are convinced. Death would not be death but the entrance into a new life. In each case we hurl ourselves against monstrous improbabilities (invraisemblances ), we float in the inhabitual, the miraculous, the prodigious."

Richet died December 3, 1935.


Berger, Arthur S., and Joyce Berger. The Encyclopedia of Parapsychology and Psychical Research. New York: Paragon House, 1991.

Gauld, Alan. The Founders of Psychical Research. New York: Schrocken Books, 1968.

Jules-Bois, A. H. "Charles Richet: Father of Metaphysics." Journal of the American Society for Psychical Research 30(1936).

Richet, Charles. Notre Sixième Sens. N.p., 1927. English ed. as Our Sixth Sense. N.p., 1929.

. Traité de Métapsychique. N.p., 1922. English ed. as Thirty Years of Psychical Research. New York: Macmillan, 1923.

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Charles Robert Richet

Charles Robert Richet

The French physiologist Charles Robert Richet (1850-1935) was awarded the Nobel Prize in Physiology or Medicine for his discovery of the phenomenon of anaphylaxis.

Charles Richet, the son of Alfred Richet, a professor in the University of Paris, was born in Paris on Aug. 25, 1850. He studied medicine in Paris and intended to become a surgeon, but he soon abandoned surgery for physiology. He graduated at Paris as a doctor of medicine in 1869 and as a doctor of science in 1878. He became a lecturer in physiology in 1879 and in 1887 professor of physiology in the Faculty of Medicine at Paris.

Discovery of Anaphylaxis

In 1890 the phenomenon of antitoxic immunity was discovered, and in 1891 diphtheria antitoxin was first used in treating diphtheria. It was soon found that the guinea pigs used for testing diphtheria antitoxin became acutely ill if long intervals separated the test injections. About 1900, while cruising in tropical waters, Richet studied the poison of the tropical jellyfish, the Portuguese man-of-war. Working with Paul Portier, he found that injection of a glycerol solution of the poison produced the symptoms of poisoning by the jellyfish. On their return to France they studied the toxins of local jellyfish. They determined the minimum dose that was fatal for dogs several days after its injection. Smaller doses than this produced only transient effects. But if a dog that had been injected with a small dose received a similar small dose after an interval of several weeks, a violent reaction killed the dog.

By 1902 Richet had studied this phenomenon in different animals. Reactions produced by the injection of antitoxins or minute doses of toxins had already been called prophylactic, or protective. Richet realized that in this new phenomenon the first dose sensitized the animal, so that the second injection produced a violent reaction. The first dose was the opposite of prophylactic, and he therefore called the phenomenon anaphylaxis. He showed clearly that the first injection of an animal toxin sensitized the test animal to even a very small second injection, and that, with very small doses, the violent symptoms following the second injection were out of all proportion to the mild symptoms following the first. He also established that, to produce the violent reaction, there must be an interval of several weeks between the injections.

In 1903 Nicolas Maurice Arthus of Lausanne described the Arthus phenomenon. If a rabbit was injected subcutaneously with repeated doses of horse serum, no effect was produced by the subsequent injections at first, but as the interval from the first injection lengthened, the injection site became swollen, hardened, and ulcerous. In 1905 Richard Otto showed that it was not the toxin in the "diphtheria antitoxin" (at that time a mixture of toxin and antitoxin was used) that produced serious effects in guinea pigs injected with repeated small doses at long intervals, but the horse serum in which the toxin was contained. Further, the reaction depended not upon the dose but upon the time interval. It was soon shown that a guinea pig injected with horse serum showed no hypersensitivity to the serum of other animals, and also that specific reactions occurred after the injection of milk, egg, or muscle extract. It was thus conclusively demonstrated that Richet's anaphylaxis was due to the injection of any protein, whether or not it was toxic on the first injection.

In 1907 Richet showed that, if the serum of an anaphylactic dog was injected into a normal dog, the latter became anaphylactic. The anaphylactic state could therefore be passively transmitted, and it was an antigen-antibody reaction. He continued to study anaphylactic phenomena, and for his work he was awarded the Nobel Prize in 1913. Anaphylaxis is closely associated with serum sickness and allergy, and later investigations of allergic diseases stem from Richet.

Richet wrote numerous works on physiology and edited two journals. He retired from his chair in 1927 and died in Paris on Dec. 4, 1935.

Further Reading

There is a biography of Richet in Nobel Lectures, Physiology or Medicine, 1901-1921 (1967), which also includes his Nobel Lecture. For his work in relation to the immunology of the period see C. Singer and E.A. Underwood, A Short History of Medicine (1962), and W. Bulloch, The History of Bacteriology (1938). □

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Richet, Charles Robert

Charles Robert Richet (shärl rōbĕr´ rēshā´), 1850–1935, French physiologist. From 1887 to 1927 he was professor at the Univ. of Paris. His special study was anaphylaxis, a term he used to describe a phenomenon noted earlier by Theobald Smith, i.e., a hyper-sensitive reaction (akin to allergy) to injections of foreign proteins, e.g., serums. For his work on anaphylaxis he received the 1913 Nobel Prize in Physiology or Medicine. He also worked on serum therapy, the nervous system, and animal heat and was interested in psychical research. Richet discovered that hydrochloric acid is the base of gastric juice.

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