Dalton, John Call

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(b. Chelmsford. Massachusetts, 2 February 1825; d. New York, New York, 12 February 1889)

medicine, physiology.

Dalton was the eldest of four sons of John Call Dalton, a prominent physician, and of Julia Ann Spalding. He graduated from Harvard College in 1844 and from the Harvard Medical School in 1847. During the next three years he probably practiced medicine in Boston. In 1848 he reported, to the Boston Society for Medical Observation, the case of a child with lead poisoning who subsequently recovered: and in 1849 he published a description of a human fetus with a malformed cranium. By means of postmortem examinations of human ovaries, Dalton established that the corpus luteum of pregnancy is distinguishable from, and persists longer than, the corpus luteum produced during the normal menstrual cycle. His essay on this subject won a prize from the American Medical Association in 1851.

By then Dalton had decided to study experimental physiology. In 1850 he visited Paris, where he attended the lectures of Claude Bernard, just as Bernard was emerging as the foremost physiologist in France. Dalton was deeply impressed by Bernard, whom he regarded afterward as his mentor. After his return to America, Dalton gave up medical practice to devote all of his time to physiology. No American had done so before, and his colleague Silas Weir Mitchell therefore later called him “our first professional physiologist.” He was professor of physiology at the University of Buffalo Medical School from 1851 to 1854, then held a similar position at the University of Vermont until 1859, when he accepted the chair of physiology at Long Island College Hospital. In 1854 he lectured on physiology in a course entitled “Physiology and Pathology” that was given at the College of Physicians and Surgeons of New York. In 1855 the College made physiology independent of pathology, through the creation of a new chair of “physiology and microscopic anatomy.” Dalton was the first person appointed to this chair.

Undoubtedly inspired by Bernard’s brilliant vivisection demonstrations, Dalton introduced into American teaching the practice of illustrating physiology lectures with experiments on live animals. During the first five years of his teaching career he repeated many of the experimental investigations recently made in Europe, confirming all of the major results through which Bernard had discovered the action of the pancreatic juice on fats, the production of sugar by the liver, and the effects on body temperature of sectioning the sympathetic nerves. While examining the larynxes of etherized dogs during the winter of 1853- 1854, Dalton observed that the glottis is opened and closed synchronously with the respiratory movements, through the action of the posterior cricoarytenoid muscles on the vocal cords. Since this observation was contrary to statements in Francois Longet’s recent textbook of physiology, Dalton published his finding.

Over the next four years he focused his research on digestion, taking up problems that were then at the center of attention of French and German physiologists. Using the gastric fistula method devised by René Blondlot and perfected by Bernard, Dalton investigated the action of gastric juice in 1854. Among the conclusions he reached was that “true” gastric juice cannot be obtained by irritating the stomach walls with indigestible substances, a method that some investigators had recommended to obtain it in a pure state; the secretion of the juice is excited only by the kinds of food it normally digests. He also found, in support of Bernard’s view, that starch is not converted to sugar in the stomach and that the action of saliva on starch does not continue in the presence of gastric juice. During this investigation, however, Dalton noticed that the presence of glucose could not always be detected, because gastric juice interfered with the standard Trommer’s test for that sugar. Later he discovered that organic substances in such fluids as gastric juice, saliva, pancreatic juice, bile, and blood serum interfered with the test for starch, blocking its color reaction with iodine. The difficulty could be overcome, he reported in 1856, by adding a little nitric acid prior to adding the iodine.

Between 1855 and 1857 Dalton carried out sixty-seven experiments on the chemical and physiological properties of bile. He confirmed Adolph Strecker’s identification of glycocholate and tauro-cholate of soda as the two characteristic ingredients of ox bile. In opposition to Strecker’s opinion, however, Dalton found in the bile of other animals substances that, although similar, were not identical with these compounds. In order to determine at what time, after feeding, the bile is secreted most abundantly, he established permanent duodenal fistulas in dogs. Collecting the intestinal fluids at various intervals after a given meal, he estimated the quantity of bile poured into the intestine, as well as its proportion to the total quantity of the intestinal fluids, by means of Pettenkofer’s test for the two characteristic bile compounds. Dalton concluded that the largest quantity of bile is secreted during the first hour, a lower but uniform quantity over the next eighteen hours, and that some bile is present at all times. Taking up the long-debated question of whether bile is a simple excretion or plays a role in digestion, he showed that the characteristic biliary compounds disappear during their passage through the intestine; they are, therefore, probably reabsorbed into the blood. He was unable, however, to detect them in the blood of the portal vein, so he had to assume that the compounds underwent some chemical change before being absorbed.

In 1859 Dalton published A Treatise on Human Physiology, designed for “students and practitioners of medicine.” Judged by his stated objective— to communicate, “in a condensed form.” the recent progress of physiology —his text was uneven. Although quite current for those areas in which he had been especially interested, such as digestion and nutrition, his discussion of other topics was less so. His chapter on the circulation made no mention of the important quantitative methods of the Ludwig school; and that on the electrical phenomena of nerve conduction relied on the work of Longet and Matteucci rather than the later, more rigorous investigations of du Bois-Reymond. Dalton dwelt at disproportionate length on those topics about which he had previously published his own investigations, while treating other equally important subjects rather cursorily. His inclusion of the stages of embryological development as an integral part of physiology had become somewhat old-fashioned by 1859. Nevertheless, Dalton’s gift for lucid, vivid description and his ability to present complex issues simply and clearly made his book eminently readable. Perhaps reflecting the dual nature of his professional position, he grounded his discussions of functions in detailed descriptions of the microscopic anatomy of the structures involved. His extensive reliance on experiments that he had repeated himself, his own chemical analyses, and illustrations drawn from his own anatomical specimens or histological preparations gave his discussions an authoritative tone. In America his textbook, which, according to Mitchell, was “without a rival,” went through seven editions by 1882.

Dalton’s Treatise reveals that, despite his admiration for Bernard, he did not always follow the latter’s views. Although he adopted Bernard’s interpretation of the functions of the pancreas and liver, he also utilaized extensively investigations such as those of Bidder and Carl Schmidt, which Bernard considered nearly useless. For his account of the nervous system Dalton relied heavily on Flourens and Longet, who had been at odds with Bernard and his teacher Magendie. (Dalton made no mention of Magendie, even in discussions of discoveries usually associated with him.)

In his Treatise Dalton reported that he had frequently repeated Flourens’s and Longet’s experiments on the removal of the cerebral hemispheres of birds. Like them, he had found that such birds could survive for long periods, that they were capable of movements and of receiving sensations, but that they had lost memory and “the power of forming mental associations.” Dalton also repeated many times the celebrated experiments in which Flourens had removed portions of the cerebellum of pigeons. Like Flourens, he found that the more extensive the portion of the cerebellum he excised, the more irregular and uncoordinated the posture, gait, and movements of the head, neck, and wings became. In January 1859, after demonstrating these phenomena to a medical class, he noticed an effect that had escaped Flourens. The pigeon, which he afterward found to have lost two-thirds of its cerebellum, survived for sixteen days, during which time it gradually recovered its muscular coordination. After attaining similar results in further experiments, Dalton concluded in 1861 that one must either suppose that the irregularity of motions results from the sudden injury to the cerebellum as a whole rather than from the loss of a part of its substance, or else that the remaining portions of the cerebellum gradually become able to take the place of the lost parts.

When the Civil War broke out, Dalton volunteered his services and was appointed surgeon to the Seventh Massachusetts Regiment. He accompanied it to Washington in 1861 and was then commissioned surgeon of a brigade of volunteers serving under Brigadier General Egbert Viele. Dalton was with this brigade during the expedition to Georgia on which it captured Port Royal Island and Fort Pulaski. He became medical director of the brigade in 1862 and thereafter supervised the treatment of sick and wounded soldiers. By 1863 he was back in New York often enough to carry on his regular physiology lectures, but he still undertook several missions to transport rebel prisoners. Chronic health problems, aggravated by malaria, induced him in 1864 to resign his commission. In the same year he was named professor of physiology at the College of Physicians and Surgeons of New York and was elected to the National Academy of Sciences.

In June 1871 Dalton read to the New York Academy of Medicine a paper entitled “Sugar Formation in the Liver,” in which he defended Bernard’s belief that the liver normally produces sugar. In 1854 another of Bernard’s former students, Frederick Pavy, had found no sugar in blood removed through a catheter from the right heart of an unanesthetized animal, whereas blood taken from the right heart after the animal was killed did contain sugar. From this and related evidence he concluded that the formation of glucose from glycogen, which Bernard had demonstrated to take place in isolated livers, was only a postmortem phenomenon. During the 1860’s a number of people attempted to settle the question of whether the liver produces sugar in life, or only after death, by analyzing pieces of liver for sugar as quickly as possible after removing the tissue from a living animal. Some of them found small quantities, others found none, so that the issue remained in dispute in 1869, when Dalton took it up. He undertook a thorough review of the question, beginning with an assessment of the relative sensitivity of the different tests for glucose. He found that Fehling’s solution was capable of detecting the smallest quantities. Then, devising a special grinder that enabled him to reduce a portion of a liver to a pulp and immerse it in alcohol within ten seconds after removing it from an animal, he was able to establish that in all cases there was an unmistakable glucose reaction. He concluded that sugar is a normal ingredient of hepatic tissue. In his Leoçons sur le diabéte (1877) Bernard used this “extremely careful work” of Dalton as a central element in his own refutation of Pavy’s criticisms.

In 1874 Dalton returned to his earlier interest in the constitution of bile, using the methods of spectroscopic analysis, which were then being applied widely to animal substances. He discovered a hitherto unnoticed absorption band in the red, characteristic of all bile having a greenish tint.

After these two papers Dalton did little original experimental work. Ill health, and his appointment as vice-president of the New York Academy of Medicine (1874-1877) and as president of the College of Physicians and Surgeons (1884), left him little time for research. In his last years, however, he did write a monumental textbook on the topography of the brain, for which he prepared all the specimens and drawings himself and closely supervised the production of photographs. He wrote essays on the experimental method in physiology as a defense against the antivivisectionist movement. Dalton also produced books on the history of the discovery of the circulation and on the history of the history of the College of Physicians and Surgeons, as well as historical lectures on spontaneous generation,” Galvani and Galvanism in the Study of the Nervous System, ““Buffon and Bonnet in the Eighteenth Century,” and “Nervous Degenerations and the Theory of Sir Charles Bell” (the last three in The Experimental Method in Medical Science). Dalton’s use of primary sources, his perceptive insights, and his clear definition of issues make his historical writings still valuable.

The many physiological experiments that Dalton performed during his years of active investigations produced no major original contributions. Most of his results merely confirmed those achieved previously by European scientists; a few provided useful emendations or extensions of earlier discoveries. According to S. Weir Mitchell, Dalton’s reputation in America exceeded what “his discoveries justified,” because his singleness of purpose, his recognition that physiology must henceforth be taught through experimental demonstrations rather than from texts, and his skill in teaching and writing enabled him to open a new era in American physiology. It was as a teacher, therefore, that Dalton played his most effective role; but it was because he devoted himself persistently to his experiments as well that he could convey to his students a realistic understanding of the nature of a rapidly developing science. Through these means he did as much as any man to prepare for the spread of physiological research from the European centers where it had originated to the American centers where it was already beginning to thrive by the time he died.


I. Original Works. Dalton’s books include On the Corpus Luteum of Menstruation and Pregnancy (Philadelphia, 1851); A Treatise on Human Physiology (Philadelphia, 1859; 7th ed., 1882); A Treatise on Physiology and Hygiene; for Schools, Families, and Colleges (New York, 1868; repr. 14 times between 1869 and 1890); Experimentation on Animals, as a Means of Knowledge in Physiology, Pathology, and Practical Medicine (New York, 1875); The Experimental Method in Medical Science (New York, 1882); Doctrines of the Circulation; a History of Physiological Opinion and Discovery, in Regard to the Circulation of the Blood (Philadelphia, 1884); Topographical Anatomy of the Brain (Philadelphia, 1885); History of the College of Physicians and Surgeons in the City of New York (New York, 1888); and John Call Dalton M. D., U. S. V. (Cambridge, Mass., 1892), a narrative of Dalton’s military experience.

Dalton’s principal scientific articles are “Some Account of the Proteus anguinus,” in Edinburgh New Philosophical Journal,60 (1853), 332-340; “On the Movements of the Glottis in Respiration,” in American Journal of the Medical Sciences,28 (1854), 75-79;”On the Gastric Juice and Its Office in Digestion, “ibid., 313-320; “On the Decomposition of lodide of Starch by the Animal Fluids,” ibid.,31 (1856), 326-330; “On the Constitution and Physiology of the Bile,” ibid34 (1857), 305-323; On the Cerebellum, as the Centre of Co-ordination of the Voluntary Movements, “ibid41 (1861), 83-88; “Anatomy of the Placenta,” in Transactions of the New York Academy of Medicine,2 (1863), 33-50; “On the Rapidity and Extent of the Physical and Chemical Changes in the Interior of the Body,” ibid.,51-76; “Sugar Formation in the Liver,”l in New York Medical Journal,14 (1871), 15-33;”On the Spectrum of Bile,” ibid., 19 (1874), 579-598; and “On the Form and Topographical Relations of the Corpus Striatum,” in Brain, 3 (1881), 145-159. A collection of letters written by Dalton and his brothers during the Civil War is in Proceedings of the Massachusetts Historical Society,56 (1923), 354-495.

II. Secondary Literature. A biographical notice and bibliography appeared in Proceedings of the American Academy of Arts and Sciences,24 (1889), 445-447. S. Weir Mitchell’s memoir, in Biographical Memoirs.National Academy of Sciences,3 (1895), 179-185, is a good general description of Dalton’s life and personality. Articles on Dalton in Dictionary of American Biograpaedia of American Biography,V (New York, 1930), 40; and in National Cyclopaedia of American Biography, X (New York, 1909), 500, rely heavily on Mitchell’s memoir.

Frederic L. Holmes