Simon Flexner was born on March 25, 1863, in Louisville, Kentucky to Helen and Morris Flexner, a Jewish German-speaking couple who'd arrived in the United States just 12 years prior. Morris Flexner had achieved moderate success with a wholesale hat business until the depression in 1872 caused the business to fail, a financial setback from which the large family never fully recovered. As a result, the Flexners were forced to move to increasingly marginal neighborhoods where the schools were inadequate and the neighbors anti-Semitic, an experience that deeply affected young Simon. He did poorly in school and was considered a failure in the Flexner family when he dropped out of school permanently at the age of 14, abandoning the eighth grade and formal education for the remainder of his youth. No longer a student, Simon trudged from one menial job to the next in order to make a contribution to the household.

Simon continued to disappoint his family with his failed efforts at keeping even the most menial of jobs. Simon managed to get fired from even a photographer's studio owned by an uncle; he was then hired out to lowly shopkeepers who couldn't afford to pay the boy more than a couple of dollars a week for his labor. Circumstances were dire; Flexner wouldn't attend school and couldn't sustain any kind of worthwhile employment. Just when it seemed circumstances couldn't be more desolate, Flexner contacted typhoid fever and death appeared imminent for the unfortunate youth. Far from killing him, however, the debilitating illness seemed to give Simon a new lease on life. The illness left him introspective and serious and as the teenager convalesced, he focused his attention on improving not only his health but also the course of his future. His new contemplative state reinforced conviction and focus in the teenager and for the first time in his life, Flexner considered the possibility that he could make a worthwhile contribution not only to his family but even to society.

The Flexner family happily supported the newly ambitious Simon and arranged for him to be apprenticed to a respected area druggist. It was a fortunate pairing; the druggist, while not overly ambitious, was kind and encouraging and Simon flourished under his tutelage. Part of his apprenticeship included a series of courses at the Louisville School of Pharmacy, where to his surprise and to the delight of his family, Flexner excelled. It was a proud moment when Simon presented the gold medal for scholastic achievement to his mother and dying father. In the evenings, Simon would take the store microscope home and conduct his own studies under the single gaslight shared by the entire family. Once a poor student, Flexner now devoted himself to learning.

In 1882, Flexner clerked at his eldest brother Jacob's drugstore where his thirst for knowledge grew. At the pharmacy, he listened intently to the gathered physicians' shoptalk and spent his evenings poring over borrowed books to familiarize himself with rudimentary medical principles. His interest in microscopy led Flexner to study histology and then pathology, an uncharted discipline at that time especially in Louisville. Local doctors increasingly brought Simon specimens and sought his opinion. It was soon apparent that Simon had learned all that he could from borrowed books; the time had arrived to pursue formal education.

Flexner dreamed of pursuing a medical education which would facilitate his dream of opening and operating a research lab, but brother Abraham's course at Johns Hopkins altered his path. Abraham, who'd been attending classes at Johns Hopkins University for two years, kept Simon abreast of university news. Upon hearing of university plans to open a medical college and, more importantly, the recent faculty hire of a professor of pathology, Simon decided to attend Johns Hopkins but in order to be admitted to the university he first would have to get a medical degree. This, as it turned out, was actually accomplished quite easily with a little help from the physicians who'd gathered at Jacob Flexner's drugstore.

The Medical Institute of the University of Louisville had never established an academic department and was therefore staffed entirely by a group of practitioners who conducted lectures - and granted degrees - rather casually. This same group, luckily for Simon, agreed to take him on as a student at a reduced rate and allowed him to attend lectures during the spare hours that he wasn't clerking at the drugstore. The physicians sympathized with Simon's familial financial obligations and since Flexner insisted that he never planned to practice medicine, they were willing to be more lenient with him. In 1889, Simon Flexner graduated from the University of Louisville with a medical degree. He immediately applied for a fellowship at Johns Hopkins.

To his disappointment, Simon wasn't chosen for the fellowship. Adding to his regret was the realization that he simply couldn't teach himself any further. Abraham offered to send Simon to Baltimore for a year of instruction as sibling Jacob had done for him. While the family, which had grown dependent on Simon's salary, wasn't entirely supportive of the decision, Simon nonetheless set off to make his mark at Johns Hopkins University with $500 from his brother Abraham.

Although Flexner had neither the benefit of a formal medical school education nor the financial stability of his classmate, the autodidact nonetheless did remarkably well with his drugstore background and extraordinary sense of discipline. Finances were Flexner's only setback. His funds were quickly running out and he faced an unwanted return to Louisville. His professors, however, refused to let a lack of finances interfere with the young man's promising future; he was offered a fellowship at the end of his first year and despite his family's fear that he would never return to Louisville, happily accepted.

In the fall of 1891, Flexner began his fellowship but under slightly different circumstances. Instead of rooming in a boardinghouse, as he'd done the previous term, he now lived with the superintendent of the hospital, which meant that he constantly interacted with clinical as well as pathology students. This proved to be a most stimulating environment for the young scientist. At the same time, the fields of bacteriology and pathology were so new that nothing but groundbreaking research opportunities awaited pioneering students. Although Flexner was slightly self-conscious about his lack of education and upbringing, for the first time in his life, close relationships with his fellow students, some of whom would also go on to become quite famous for their work in infectious disease research. Meanwhile, the medical school, which had been postponed due to lack of funding, was now slated for a fall 1893 opening.

Flexner began his work on meningitis in early 1892 when an epidemic broke out in the coal-mining region of Cumberland, Maryland. Flexner and another scientist performed an autopsy on a young girl and although the bereaved parents insisted that the body remain intact, Flexner sneaked tissue samples out of the house in order to determine whether the epidemic was actually spotted fever as originally believed or an outbreak of meningitis. Flexner determined that it was definitely an outbreak of meningitis and set off on a course of study linking meningitis with pneumonia. While his theory eventually proved wrong, it launched Flexner's lifetime research on the disease.

Simon completed his second year at Johns Hopkins and saw some of the pathology faculty leave the university for opportunities elsewhere. Torn between leaving Johns Hopkins for a faculty position or staying and hoping for a promotion that might never materialize due to his lack of experience, Flexner was uneasy about his prospects. He perceived stiff competition among his fellow students but when his mentor and faculty member, William T. Councilman decided to leave for Harvard, Flexner received the assistant in pathology appointment. Within two years of arriving at Johns Hopkins, Flexner became not only a faculty member but also slated to succeed Councilman's successor as resident pathologist at the hospital. This time the entire Flexner family supported Simon's appointment.

Flexner spent the next year doing autopsies, research, and lecturing and although he was confident in his abilities, he recognized that he could benefit from a period of German study, standard for young medical students at that time. At the end of the first semester in 1893, he set sail for Germany. It was a successful trip in the sense that although Flexner visited many universities abroad, he returned with a deeper appreciation for the Johns Hopkins University, which employed a much more egalitarian approach than the medical schools he'd seen in Eastern and Western Europe.

By the time Flexner returned from Europe in the fall of 1893, the eagerly awaited medical school was finally open but more importantly, the pathology department had been expanded to twice the size. The medical school student body consisted of fourteen men and three women; the inclusion of the latter was not included in the original plan but became a condition of funding. Stringent admission requirements further reduced enrollment. Upon his return, Flexner resumed his exhausting schedule of supervising the pathology laboratory and assisting with pathology courses. At the same time, he continued his research on diphtheria and toxins, which introduced him to the new field of immunology. Flexner also managed to write extensively in conjunction with his research, ultimately publishing more than seventy articles between 1893 and 1899.

Flexner conducted important research on toxins and diphtheria during 1893-1894, which contributed to the discovery of a cure and led him to inadvertently stumble on the phenomenon of anaphylaxis. He was invited to speak before the Pathological Society of Philadelphia on his toxin research; this presentation he later claimed established his reputation in Philadelphia, then considered to be the capital of American medicine. Continuing to do autopsies also presented Flexner with valuable research opportunities. A case of acute pancreatitis, for example, led Flexner to study the pancreas carefully and after thirty years of continuous research ultimately led to the isolation of insulin.

Elected to the American College of Physicians in 1895, Flexner was also promoted to associate professor of pathology, a remarkable feat for one who'd arrived at Johns Hopkins less than five years prior as a very inexperienced student. Other universities offered Flexner, who was lamentably underpaid, faculty positions at higher salaries but with fewer research opportunities. His mentor, William Welch, encouraged Flexner to be selective in light of his growing reputation as one of leading pathologists in the country. Although uncertain about his future, Flexner decided to stay at "the Hopkins" when they offered him a slight increase in salary; he felt comfortable there and his research benefited from the network he'd established with the other researchers.

Even the appointment of full professorship didn't seem to assure Flexner of a secure future at Johns Hopkins. He decided to resume negotiations with Cornell and also the University of Pennsylvania when he learned of the opening in pathology. Flexner decided on the University of Pennsylvania despite the lower salary and rumors of anti-Semitism. While the negotiations continued, he decided to go to the Philippines on a research expedition with his close friend and colleague, Lewellys F. Barker. The University of Pennsylvania confirmed his appointment as the men prepared for their expedition giving Flexner reservations about leaving just as the position of his dreams had finally opened. Eventually he decided to go and the trip proved a great success, scientifically speaking.

The beauty of Japan, where the group decided to spend some time, enchanted Flexner but he found himself craving structure and anxious to begin working. The group traveled to Tokyo, the center of infection disease research where Shibasaburo Kitasato, a codiscoverer of the diphtheria antitoxin, invited them into the laboratories. Flexner's introduction to scientist Hideyo Noguchi was most significant. Noguchi immediately expressed a desire to work with Flexner. Flexner's response was polite; at the time, he had no idea of the impact Noguchi would have in his own personal life, his career, and even the history of science itself.

The group traveled next to Hong Kong and then into the Philippine Islands. The "plague" and other infectious diseases were on the rise in Manila, offering plentiful virology research opportunities. The commission studied typhoid fever, malarial fevers, tuberculosis, and dengue fever, topical ulcers and dysentery, in which Flexner had the greatest interest. Aside from the research opportunities, Flexner found Manila depressing and the group decided to leave early. Flexner took a long voyage home and was back in Philadelphia with time to spare before his new position started.

Meanwhile there was an implosion in the tightly knit Flexner family, which left Abraham, the founder of a very successful school for boys, trying to keep the family afloat. Jacob Flexner, the acting patriarch since the death of their father years before, revealed that he was overextended financially and close to losing his drugstore. Abraham refused to let the family declare bankruptcy and for a time managed to juggle the debt incurred by various Flexner family members. It was a losing battle, however, and although he somehow saved the newly constructed family houses from foreclosure, Jacob lost his drugstore.

Jacob decided to try his hand at medicine. At Abraham's urging he joined Simon at Johns Hopkins. It was an uncomfortable time for Simon. Jacob, never prone to humility even in the face of his financial failures, embarrassed the quiet Simon with his overbearing and belligerent manner. Luckily, he attended the university for just a few months and then went on to New York for further training. In the end Simon felt as if the declaration of bankruptcy had liberated the Flexner family; everyone could now pursue desired careers without considering the family finances.

Flexner arrived in Philadelphia in 1899 to begin his professorship at the University of Pennsylvania. It was not smooth sailing. The faculty resented Flexner and resisted change. Senior faculty members were cool towards Flexner and opposed his ambitious plans to expand the pathology department. Flexner was barred from even hiring his own assistants. But students immediately responded warmly and enthusiastically to Flexner who lectured three days a week.

Soon after he began in Philadelphia, Flexner was surprised by the arrival of Hideyo Noguchi, the bacteriologist from Japan. Flexner had written to Noguchi that there wasn't a position available in Philadelphia but Noguchi had taken upon himself to make the trip prior to Flexner's discouraging response. There was nothing to do but put Noguchi to work in the pathology lab. Though Noguchi needed training, like Flexner he proved to be a quick study and an invaluable assistant. Noguchi went on to do brilliant research work on syphilis and yellow fever. The two developed a close relationship and it is most telling that when Flexner moved on to the Rockefeller Institute, Noguchi was the only member of his Philadelphia group who was chosen to join the staff at the new facility.

Flexner's time at the University of Pennsylvania was perhaps the most social period of his life. Most of the faculty members eventually warmed to the young man and included him in social gatherings. The salary increase also allowed him to go out more often. It wasn't long after he'd arrived at Pennsylvania though that he met his future wife, Helen Thomas. The sister of former Johns Hopkins colleague and friend Harry Thomas, she taught at nearby Bryn Mawr College where older sister Carey was dean.

During 1900-1901, his second year at the University of Pennsylvania, Flexner gained a hospital pathologist position as well as an appointment as director of the university's Ayer Clinical Laboratory which Flexner insisted should be used for research in conjunction with medical school classes. His background in plague research led him to be appointed head of a federal commission to investigate an outbreak in San Francisco that same year. At the same time, he continued with his own research on immunology with Noguchi. They worked together to study the toxic effects of snake venom, a research project suggested by Dr. Weir Mitchell who'd studied the effects of snake venom on humans and wanted Flexner to pursue experimental immunology.

That same year, 1901, Flexner received an appointment to the Board of Scientific Directors of the newly formed Rockefeller Institute for Medical Research, endowed by John D. Rockefeller. The next year the Institute offered Flexner the opportunity to direct laboratories and organize operations, a brilliant opportunity. To leave the university was risky because Rockefeller had guaranteed funding for only ten years. Flexner agonized over leaving his prestigious position at Penn but in the end, he accepted. By this time, Flexner and Helen Whitall Thomas were engaged.

Flexner and his new bride spent much of 1903, the first year of his appointment, visiting research laboratories in Europe seeking a model for the Rockefeller Institute. Realizing that chemistry, physics, and experimental biology were increasing becoming a central component of virology research, Flexner hired only scientists with a command of the basic sciences. When the Institute opened in 1906, the staff included Samuel J. Meltzer, Phoebus A. Levene, Eugene L. Opie, Hideyo Noguchi, Alexis Carrel, Jacques Loeb, Rufus I. Cole, and Peyton Rous.

Flexner's own research, meanwhile, rapidly gained attention and acclaim by the general public. This translated into winning public support for the new Institution and assured Rockefeller's continued financial backing. When New York City suffered a severe cerebrospinal meningitis epidemic during 1904 and 1905, Flexner studied the disease and by 1907 was able to develop an antiserum that acted against the bacterial agent and reduced the mortality rate by fifty percent. The Institute developed and distributed the serum to the general public free of charge. In 1907 Flexner took the same approach with polio and while his conclusions proved to be incorrect, he nonetheless laid important groundwork for researching the disease.

John D. Rockefeller, completely confident in Flexner, agreed to finance a research hospital at the Institute in 1910. During World War I, Flexner implemented a program to train medical officers and technicians and taught bacteriology himself. Serving in the Army Medical Corps from 1917-1919, Flexner attained the rank of colonel and assumed responsibility for inspecting the expeditionary forces laboratories in Europe.

While hired to just direct the laboratory, Flexner's superior administrative skill had essentially made him acting director of the entire facility. In 1924, he was formally named Director of the Rockefeller Institute, an amazing accomplishment that the entire Flexner family celebrated.

In addition to overseeing the daily operations of the Institute, Flexner worked tirelessly to aid other agencies in promoting medical and scientific education. He served as a charter member of the Rockefeller Foundation, the largest medical education and research benefactor, and helped the National Research Council secure funding for medical and mathematical research. He served on the Johns Hopkins Medical School board of trustees and chaired the Public Health Council of New York State.

A participating member of many scientific organizations throughout his career, Flexner served as president of the Association of American Physicians in 1914 and the American Association for the Advancement of Science and the Congress of American Physicians and Surgeons in 1919. The National Academy of Sciences recognized his contributions with a membership in 1908.

Flexner acted as director of the Rockefeller Institute until his retirement in 1935. During 1937 and 1938, he traveled to Oxford University as Eastman Professor acting as a consultant on medical professorships. During his time in England, Flexner wrote The Evolution and Organization of the University Clinic. In 1942, Flexner and his son, James Thomas Flexner, co-authored a well-received biography, William Henry Welch and the Heroic Age of American Medicine. Simon Flexner died in New York City at the age of 83.

The Rockefeller Institute series, the first of two in the collection, is approximately 150 linear feet of mostly Institute-related material. Flexner's early years at Johns Hopkins and the University of Pennsylvania are not documented in this collection but there is, however, a substantial amount of material reflecting Flexner's early interest in virology, pathology and bacteriology within his notes, notebooks and diaries.

Much of the correspondence in the collection is dated after his Rockefeller Institute appointment except for communication between Flexner and Helen Whitall Thomas and various family members. Flexner's research and scientific interests led him to form lifelong relationships with other scientists, researchers, and medical practitioners; therefore much of the correspondence spans decades.

There is correspondence with Frederick Gates, business manager to John D. Rockefeller. Instrumental in convincing Rockefeller of the impact that a medical research facility would have for all of mankind, he successfully persuaded Rockefeller to finance a research facility. In 1901 a planning committee was formed. Persons involved in the early stages of the Rockefeller Institute included William H. Welch, Hermann Briggs, Emmett Holt, Christian Herter, Theobald Smith, and Simon Flexner.

As director of the Rockefeller Institute, Flexner chose his staff carefully. Ultimately, the Institute staff included: Samuel J. Meltzer, Phoebus A. Levene, Eugene L. Opie, Hideyo Noguchi, Alexis Carrel, Jacques Loeb, Rufus I. Cole, and Peyton Rous. There is a great deal of correspondence between Flexner and his candidates that document the accomplishments of these men and illustrate the role they filled within the Institute.

In 1909, the Rockefeller Hospital was completed with Rufus Cole named as director. The correspondence between Cole and Flexner covers mostly administrative manners but also mentions some of the groundbreaking scientific research in the laboratories by D. D. Van Slyke, A. E. Cohn and A. E. Mirsky. Theobald Smith headed the Institute's department of animal pathology in Princeton opened in 1916 and mentions research at the department, particularly the work of pathologist John W. Gowen.

Between 1901 and 1913, the Rockefeller philanthropies established the General Education Board with Wallace Buttrick as its President; the China Medical Board; the Sanitary Commission to Eradicate Hookworm Disease; the International Health Commission with Wickliffe Rose as director. The Rockefeller Foundation was incorporated in 1913. Flexner became a trustee that same year along with John D. Rockefeller, Frederick L. Gates, Henry Pratt Judson, Starr J. Murphy, Jerome D. Greene, Wickliffe Rose, Charles O. Heydt and later, Charles William Eliot and A. Barton Hepburn. The collection is rich in correspondence concerning individual Rockefeller boards and funding history both in the United States and abroad. Perhaps most significant is the work of the General Education Board and the Rockefeller Foundation in supporting the development of medical education following the publication of Abraham Flexner's report on North American medical schools.

The reorganization of the Foundation in 1928 led to the creation of the Division of Natural Sciences, first directed by Max Mason and then Hermann A. Spoer and from 1932 on, by Warren Weaver. There is an abundance of material on the Foundation's reorganization. Much of the material is devoted to the early 1930's when Weaver began to shift the funding direction from financing the construction of research facilities to the actual practice of research.

The following is a short list of Flexner's correspondents mentioned primarily because the sheer amount of correspondence with Flexner indicates a significant relationship in some aspect. It is by no means a comprehensive list. There is a substantial amount of correspondence with Harold L. Amoss. Amoss, an American physician, worked with Flexner to develop a dysentery serum. Other scientists who corresponded with Flexner were Swiss physiologist and biochemist, Emil Abderhalden; John J. Abel, American physiological chemist; James Arthur Bain, American pharmacologist and Rockefeller fellow; Canadian physician and Nobel Prize recipient, Frederick Grant Banting; Johns Hopkins colleague and longtime friend, Lewellys F. Barker; Hermann Michael Biggs, American physician and bacteriologist, (Biggs wrote about tuberculosis and cholera; he also organized the bacteriology labs of the New York City Health Department).

Carl Alfred Lanning Binger, American psychiatrist; Wade Hampton Brown, American pathologist; Carroll G. Bull, American immunologist; Walter B. Cannon, American physiologist; Alexis Carrel; Rufus Cole; Frederick Fuller, American physician; Phoebus Aaron Theodore Levene, American physiologist, Winthrop John Vanleuven Osterhout; Russian-born chemist; Richard Mills Pearce, pathologist; F. Peyton Rous, American physician and virologist; Theobald Smith, American pathologist; Hans Zinsser, American bacteriologist.

There are 65 Simon Flexner folders and almost 170 subject files. There are many files on meningitis, poliomyelitis, and tryparsamide.

Provenance

Acquired, 1964.

Preferred citation

Cite as: Simon Flexner Papers, American Philosophical Society.

Processing information

Recatalogued by A. Harney, June, 2003. Michael Miller incorporated the information from Margaret Miller's guide into this finding aid in 2007.

Other finding aids

The Simon Flexner Papers are also described in Margaret Miller's Guide to Selected Files of the Professional Papers of Simon Flexner at The American Philosophical Society.

The Simon Flexner Papers are also described in Lilly Kay's Molecules, Cells and Life. The information from this subject guide has been incorporated below in the Physiology, Biochemistry, and Biophysics Note.

Separated material

Photographs were removed from the Flexner Papers for storage with the APS graphics collections, but digitized images have been inventoried here in series II. View gallery of digitized photographs.

Related material

Other related material at The American Philosophical Society include:

Related collections located at the Rockefeller Archives Center include:

Related materials also at the Library of Congress, Washington, D.C., Connecticut Agricultural Experiment Station, Marine Biological Laboratories, Woods Hole, California Institute of Technology Archives and the National Library of Medicine, Bethesda, Maryland.

1. The Simon Flexner Family Papers
2. Francis Peyton Rous Papers
3. Hans Thacher Clarke Papers
4. Cyril Norman Hugh Long Papers
5. Rufus Ivory Cole Papers
6. Max Bergmann Papers
7. Eugene Lindsay Opie Papers
8. Winthrop John Van Leuven Osterhout Papers
9. Peter K. Olitsky Papers
10. Landsteiner-Mackenzie Papers
11. Florence Rena Sabin Papers
12. James B. Murphy Papers
13. Oswald H. Robertson Papers
14. Thomas M. Rivers Papers
15. Leslie T. Webster Papers
16. Charles Benedict Davenport Papers
17. Leslie Clarence Dunn Papers
18. Franz Boas Papers
19. Harold Lindsay Amoss Papers

1. Records of the Rockefeller Institute for Medical Research
2. Papers of the General Education Board
3. Papers of the China Medical Board
4. Records of the Rockefeller Foundation
5. International Education Board Papers
6. papers of the Rockefeller Sanitary Commission for the Eradication of Hookworm Disease, Washington, D.C.

Bibliography

Physiology, Biochemistry, and Biophysics Note

Simon Flexner was one of the most influential figures in the life sciences in America, and a prominent member of the scientific establishment that shaped the country's intellectual and social development. Major aspects of this growth are documented in this voluminous collection, which includes correspondence, diaries (circa 1900, 1915-1944), laboratory notebooks (circa 1900-1920), and drafts of articles and addresses. The early phases of Flexner's academic career -- his medical education at the University of Louisville, his subsequent move to Johns Hopkins (1890-1899), and his tenure at the University of Pennsylvania as professor of pathology (1899-1906) -- are not covered in this collection (however, a number of secondary sources fill these gaps). The entry on Flexner in this note therefore addresses only those files which bear on the intellectual and institutional development of physiology, biochemistry, and biophysics. Flexner influenced the growth of physiology, biochemistry, and biophysics in two ways: as director of the Rockefeller Institute, and through his positions of leadership in the Rockefeller Foundation, the National Research Council, the Carnegie Foundation and other scientific organizations and journals; his professional papers reflect both aspects of his influence.

P. A. Levene was selected by Simon Flexner in 1905 to head the biochemistry program at the newly created Rockefeller Institute for Medical Research. He worked there until his retirement in 1939. By the time he joined the Institute, Levene was already well into his second career. Having abandoned medicine for chemistry, he had supplemented his chemistry training at Columbia University with study in the laboratories of Edmund Drechsel, Albrecht Kossel, and Emil Fischer. From Kossel he acquired an interest in nucleic acids, which developed into a major research program at the Institute.

One of Levene's most important contributions was the isolation and identification in 1909 of the carbohydrate portion of the nucleic acid molecule. That year he showed that ribose was found in some nucleic acids (RNA), and in 1929 he identified deoxyribose in another class of nucleic acids (DNA). However, his tetranucleotide hypothesis of DNA composition was disproved in the 1940s by the work of Erwin Chargaff. Levene was an exceptionally effective laboratory researcher, and his technical skills enabled him to carry out numerous and diverse biochemical analyses. In more than 700 publications, Levene addressed the chemistry of nucleic acids, proteins, glycoproteins, sugars, and lipids; all this was aimed at explaining basic physiological processes in a chemical language.

The American odyssey of the German physiologist Jacques Loeb began in 1891 at Bryn Mawr College, followed by eleven years at the University of Chicago, the University of California at Berkeley, and from 1910 until his death at the Rockefeller Institute in New York; the summers were spent at the marine biological laboratories at Woods Hole and Pacific Grove.

During those years Loeb's work increasingly moved toward physicochemical explanations of life. A materialist and an arch-determinist, Loeb's research program was based on a mechanistic conception of life. His studies of phototropism aimed at demonstrating that instincts of organisms were merely photochemical phenomena, his experiments on artificial parthenogenesis in sea urchins were undertaken in order to prove that ordinary physicochemical agents could initiate the development of life. In his last decade, Loeb's work focused mainly on proteins as the agents of life, a unification of physiology and physiological chemistry.

Loeb's striking experimental feats captured the popular and scientific imagination; his charismatic personality and cultivated manner added to his fame. Through his work and personal style he had a profound impact on the development of a non-medical general physiology. Although Loeb preferred not to participate in administrative activities and avoided bureaucratic entanglements, he was one of the most visible scientists of his generation.

John Howard Northrop, an intellectual heir to a long line of scholars, had always been intrigued by the vitalist-mechanist debate. In search of insights into the nature of life, he began his advanced training in biology with Thomas Hunt Morgan and Edmund Beecher Wilson at Columbia University, but soon turned to the study of physical and biological chemistry (under J. H. Nelson), where he felt he could find exact explanations of vital processes. In 1915 Northrop joined Jacques Loeb at the Rockefeller Institute, collaborating on a variety of projects, but his interests were increasingly moving toward the biochemistry of viruses, bacteriophage, and enzymes.

In the late 1920s and 1930s this interest developed into a major research program at the Princeton branch of the Rockefeller Institute. During these years Northrop had crystallized several proteolytic enzymes and showed some of them to be autocatalytic proteins, work that also contributed to the crystallization of the tobacco mosaic virus by his colleague Wendell Meredith Stanley. In the late 1930s Northrop returned to studies of viruses, concentrating mainly on the biochemistry of bacteriophage. In 1946 he was awarded the Nobel Prize (shared with Stanley and James B. Sumner) for his work on enzymes.

In addition to his research on proteins, Northrop distinguished himself on other fronts. During World War I he had developed a microbial process for producing acetone, and during World War II, techniques for measuring mustard gas. Northrop was also Simon Flexner's confidant; his judgment on research problems and researchers, on administrative matters and editorial issues was frequently solicited by Flexner and other members of the Institute.

The scientific career of Donald D. Van Slyke was spent at the Rockefeller Institute for Medical Research. Beginning in 1907 in the biochemistry laboratory of P. A. Levene, Van Slyke went on to become chief chemist of the hospital of the Institute, where he stayed until his move to the Brookhaven National Laboratory in 1949.

Undoubtedly influenced by his medical environment, Van Slyke's research program in physical biochemistry focused on studies of gas, fluid, and acid-base equilibria in relation to pathology. One of Van Slyke's chief interests was the analysis of physicochemical equilibria in blood. In collaboration with Lawrence J. Henderson, Van Slyke developed a series of studies on the acid-base properties of hemoglobin. In these and other biomedical investigations, Van Slyke relied heavily on accurate measurements, employing instruments and analytical techniques he had devised, notably his manometric apparatus for blood-gas analysis.

The move of Ralph W. G. Wyckoff from the Geophysical Laboratory of the Carnegie Institution of Washington to the Rockefeller Institute in 1927 marked an important development in the history of both the Institute and American biophysics. Under Wyckoff's leadership, a new subdivision was formally designated as biophysics. Wyckoff initiated his program with the study of x-ray crystallography of simple inorganic and organic molecules with an eye to determining the molecular structures of complex macromolecules such as proteins. Together with Robert B. Corey (who joined Linus Pauling's group at Caltech when Wyckoff left the Institute in 1937) they laid some of the early foundations for determining the structures of amino acids.

During the 1930s, Wyckoff in collaboration with several members of the International Health Division of the Rockefeller Foundation designed an air-driven ultracentrifuge, far simpler and cheaper than the machine built by Theodor Svedberg. The domestic ultracentrifuge was especially important to the virus studies of Wendell M. Stanley. Wyckoff also collaborated with Peyton Rous and James Bumgardner Murphy in the 1930s on electromagnetic methods of isolating microphages.

The significance of Wyckoff's research transcends his technical accomplishments. Wyckoff was a champion of the new field of biophysics, and made a deliberate effort to define and shape it. The Flexner Papers contain material which address both the technical and disciplinary aspects of the new biophysics. There is correspondence on x-ray crystallography and viruses, and an informative report on the future of biophysics. These materials should be of value in reconstructing the convoluted history of American biophysics.

• Rockefeller Foundation
• Rockefeller Institute for Medical Research

• Diaries.
• Gelatin silver prints
• Landscape photographs
• Portrait photographs

• Cairns, Hugh, Sir, 1896-1952
• Cannon, Walter B. (Walter Bradford), 1871-1945
• Carrel, Alexis, 1873-1944
• Cohn, Alfred E. (Alfred Einstein), 1879-1957
• Cole, Rufus Ivory, 1872-1966
• Conklin, Edwin Grant, 1863-1952
• Councilman, W.T. (William Thom
• Flexner, Abraham, 1866-1959
• Flexner, Simon, 1863-1946
• Gowen, John Whittemore, 1893-1
• Lee, Frederic S. (Frederic Sch
• Leishman, William B., Sir, 186
• Levene, P. A. (Phoebus Aaron),
• Mall, Franklin P. (Franklin Pa
• Meltzer, Samuel James, 1851-19
• Mirsky, Alfred E.
• Noguchi, Hideyo, 1876-1928
• Olitsky, Peter K.
• Opie, Eugene L. (Eugene Lindsay), 1873-1971
• Osborn, Henry Fairfield, 1857-
• Osten, Anna L. von der
• Sabin, Albert B. (Albert Bruce)
• Saddington, Ronald S.
• Shaw, Edward B.
• Shope, Richard E. (Richard Edwin)
• Smith, Theobald, 1859-1934
• Spielmeyer, W. (Walther), b. 1
• Stewart, Walter B.
• Stokes, Joseph (1896-1972)
• Thomas, M. Carey (Martha Carey
• Vallery-Radot, Pasteur, 1886
• Van Slyke, Donald Dexter, 1883-1971
• Veblen, Oswald, 1880-1960
• Wadsworth, Augustus Baldwin, 1
• Welch, William Henry, 1850-1934

• Diseases
• Education-United States
• Epidemics -- United States
• Immunology
• Indians of North America -- Arizona
• Indians of North America -- New Mexico
• Medical education-United States
• Medical sciences-United States
• Medicine-United States
• Meningitis, Cerebrospinal-United States
• Navajo Indians
• Papago Indian Reservation (Ariz.)
• Pathology-United States
• Poliomyelitis-United States
• Public Health-United States