Florence Rena Sabin's studies of the central nervous system of newborn infants, the origin of the lymphatic system, and the immune system's responses to infections—especially by the bacterium that causes tuberculosis—carved an important niche for her in the annals of science. She also researched and taught at Johns Hopkins School of Medicine and Rockefeller University.
In addition to her contributions to science, Florence Sabin's later work as a public health administrator left a permanent imprint upon the communities in which she served. Some of the firsts achieved by Sabin include becoming the first woman faculty member at Johns Hopkins School of Medicine, as well as its first female full professor, and the first woman to be elected president of the American Association of Anatomists.
Sabin was born on November 9, 1871, in Central City, Colorado, to George Kimball Sabin, a mining engineer and son of a country doctor, and Serena Miner, a teacher. Her early life, like that of many in that era, was spare: the house where she lived with her parents and older sister Mary had no plumbing, no gas and no electricity. When Sabin was four, the family moved to Denver; three years later her mother died.
After attending Wolfe Hall boarding school for a year, the Sabin daughters moved with their father to Lake Forest, Illinois, where they lived with their father's brother, Albert Sabin. There the girls attended a private school for two years and spent their summer vacations at their grandfather Sabin's farm near Saxtons River, Vermont.
Sabin graduated from Vermont Academy boarding school in Saxtons River and joined her older sister at Smith College in Massachusetts, where they lived in a private house near the school. As a college student, Sabin was particularly interested in mathematics and science, and earned a bachelor of science in 1893. During her college years she tutored other students in mathematics, thus beginning her long career in teaching.
A course in zoology during her junior year at Smith ignited a passion for biology, which she made her specialty. Determined to demonstrate that, despite widespread opinion to the contrary, an educated woman was as competent as an educated man, Sabin proceeded to chose medicine as her career. This decision may have been influenced by events occurring in Baltimore at the time.
The opening of Johns Hopkins Medical School in Baltimore was delayed for lack of funds until a group of prominent local women raised enough money to support the institution. In return for their efforts, they insisted that women be admitted to the school—a radical idea at a time when women who wanted to be physicians generally had to attend women's medical colleges.
In 1893 the Johns Hopkins School of Medicine welcomed its first class of medical students; but Sabin, lacking tuition for four years of medical school, moved to Denver to teach mathematics at Wolfe Hall, her old school. Two years later she became an assistant in the biology department at Smith College, and in the summer of 1896 she worked in the Marine Biological Laboratories at Woods Hole. In October of 1896 she was finally able to begin her first year at Johns Hopkins.
While at Johns Hopkins, Sabin began a long professional relationship with Dr. Franklin P. Mall, the school's professor of anatomy. During the four years she was a student there and the fifteen years she was on his staff, Mall exerted an enormous influence over her intellectual growth and development into prominent scientist and teacher. Years after Mall's death, Sabin paid tribute to her mentor by writing his biography, Franklin Paine Mall: The Story of a Mind.
Sabin thrived under Mall's tutelage, and while still a student she constructed models of the medulla and mid-brain from serial microscopic sections of a newborn baby's nervous system. For many years, several medical schools used reproductions of these models to instruct their students. A year after her graduation from medical school in 1900, Sabin published her first book based on this work, An Atlas of the Medulla and Midbrain, which became one of her major contributions to medical literature, according to many of her colleagues.
After medical school, Sabin was accepted as an intern at Johns Hopkins Hospital, a rare occurrence for a woman at that time. Nevertheless, she concluded during her internship that she preferred research and teaching to practicing medicine. However, her teaching ambitions were nearly foiled by the lack of available staff positions for women at Johns Hopkins. Fortunately, with the help of Mall and the women of Baltimore who had raised money to open the school, a fellowship was created in the department of anatomy for her. Thus began a long fruitful period of work in a new field of research, the embryologic development of the human lymphatic system.
Sabin began her studies of the lymphatic system to settle controversy over how it developed. Some researchers believed the vessels that made up the lymphatics formed independently from the vessels of the circulatory system, specifically the veins. However, a minority of scientists believed that the lymphatic vessels arose from the veins themselves, budding outward as continuous channels. The studies that supported this latter view were done on pig embryos that were already so large (about 90mm in length) that many researchers—Sabin included—pointed out that the embryos were already old enough to be considered an adult form, thus the results were inconclusive.
The young Johns Hopkins researcher set out to settle the lymphatic argument by studying pig embryos as small as 23mm in length. Combining the painstaking techniques of injecting the microscopic vessels with dye or ink and reconstructing the three-dimensional system from two-dimensional cross sections, Sabin demonstrated that lymphatics did in fact arise from veins by sprouts of endothelium (the layer of cells lining the vessels). Furthermore, these sprouts connected with each other as they grew outward, so the lymphatic system eventually developed entirely from existing vessels. In addition, she demonstrated that the peripheral ends (those ends furthest away from the center of the body) of the lymphatic vessels were closed and, contrary to the prevailing opinion, were neither open to tissue spaces nor derived from them. Even after her results were confirmed by others they remained controversial. Nevertheless, Sabin firmly defended her work in her book The Origin and Development of the Lymphatic System.
Sabin's first papers on the lymphatics won the 1903 prize of the Naples Table Association, an organization that maintained a research position for women at the Zoological Station in Naples, Italy. The prize was awarded to women who produced the best scientific thesis based on independent laboratory research.
Back at Hopkins from her year abroad, she continued her work in anatomy and became an associate professor of anatomy in 1905. Her work on lymphatics led her to studies of the development of blood vessels and blood cells. In 1917 she was appointed professor of histology, the first woman to be awarded full professorship at the medical school. During this period of her life, she enjoyed frequent trips to Europe to conduct research in major German university laboratories.
After returning to the United States from one of her trips abroad, she developed methods of staining living cells, enabling her to differentiate between various cells that had previously been indistinguishable. She also used the newly devised "hanging drop" technique to observe living cells in liquid preparations under the microscope. With these techniques she studied the development of blood vessels and blood cells in developing organisms—once she stayed up all night to watch the "birth" of the bloodstream in a developing chick embryo. Her diligent observation enabled her to witness the formation of blood vessels as well as the formation of stem cells from which all other red and white blood cells arose. During these observations, she also witnessed the heart make its first beat.
Sabin's technical expertise in the laboratory permitted her to distinguish between various blood cell types. She was particularly interested in white blood cells called monocytes, which attacked infectious bacteria, such as Mycobacterium tuberculosis, the organism that causes tuberculosis. Although this organism was discovered by the German microbiologist Robert Koch during the previous century, the disease was still a dreaded health menace in the early twentieth century. The National Tuberculosis Association acknowledged the importance of Sabin's research of the body's immune response to the tuberculosis organism by awarding her a grant to support her work in 1924.
In that same year, she was elected president of the American Association of Anatomists, and the following year Sabin became the first woman elected to membership in the National Academy of Sciences. These honors followed her 1921 speech to American women scientists at Carnegie Hall during a reception for Nobel Prize-winning physicist Marie Curie, an event that signified Sabin's recognized importance in the world of science.
Although her research garnered many honors, Sabin continued to relish her role as a professor at Johns Hopkins. The classes she taught in the department of anatomy enabled her to influence many first-year students—a significant number of whom participated in her research over the years. She also encouraged close teacher-student relationships and frequently hosted gatherings at her home for them.
One of her most cherished causes was the advancement of equal rights for women in education, employment, and society in general. Sabin considered herself equal to her male colleagues and frequently voiced her support for educational opportunities for women in the speeches she made upon receiving awards and honorary degrees. Her civic-mindedness extended to the political arena where she was an active suffragist and contributor to the Maryland Suffrage News in the 1920s.
Sabin's career at Johns Hopkins drew to a close in 1925, eight years after the death of her close friend and mentor Franklin Mall. She had been passed over for the position of professor of anatomy and head of the department, which was given to one of her former students. Thus, she stepped down from her position as professor of histology and left Baltimore.
In her next position, Sabin continued her study of the role of monocytes in the body's defense against the tubercle bacterium that causes tuberculosis. In the fall of 1925, Sabin assumed a position as full member of the scientific staff at the Rockefeller Institute for Medical Research (now Rockefeller University) in New York City at the invitation of the institute's director, Simon Flexner . At Rockefeller Sabin continued to study the role of monocytes and other white blood cells in the body's immune response to infections. She became a member of the Research Committee of the National Tuberculosis Association and aspired to popularize tuberculosis research throughout Rockefeller, various pharmaceutical companies, and other universities and research institutes. The discoveries that she and her colleagues made concerning the ways in which the immune system responded to tuberculosis led her to her final research project: the study of antibody formation.
During her years in New York, Sabin participated in the cultural life of the city, devoting her leisure time to the theater, the symphony, and chamber music concerts she sometimes presented in her home. She enjoyed reading nonfiction and philosophy, in which she found intellectual stimulation that complemented her enthusiasm for research. Indeed, one of her co-workers was quoted in Biographical Memoirs as saying that Sabin possessed a "great joy and pleasure which she derived from her work … like a contagion among those around her so that all were stimulated in much the same manner that she was….She was nearly always the first one at the laboratory, and greeted every one with a joie de vivre which started the day pleasantly for all of us."
Meanwhile, she continued to accrue honors. She received fourteen honorary doctorates of science from various universities, as well as a doctor of laws. Good Housekeeping magazine announced in 1931 that Sabin had been selected in their nationwide poll as one of the twelve most eminent women in the country. In 1935 she received the M. Carey Thomas prize in science, an award of $5,000 presented at the fiftieth anniversary of Bryn Mawr College. Among her many other awards was the Trudeau Medal of the National Tuberculosis Association (1945), the Lasker Award of the American Public Health Association (1951), and the dedication of the Florence R. Sabin Building for Research in Cellular Biology, at the University of Colorado Medical Center.
In 1938 Sabin retired from Rockefeller and moved to Denver to live with her older sister, Mary, a retired high school mathematics teacher. She returned to New York at least once a year to fulfill her duties as a member of both the advisory board of the John Simon Guggenheim Memorial Foundation and the advisory committee of United China Relief.
Sabin quickly became active in public health issues in Denver and was appointed to the board of directors of the Children's Hospital in 1942 where she later served as vice president. During this time she became aware of the lack of proper enforcement of Colorado's primitive public health laws and began advocating for improved conditions. Governor John Vivian appointed her to his Post-War Planning Committee in 1945, and she assumed the chair of a subcommittee on public health called the Sabin Committee. In this capacity she fought for improved public health laws and construction of more health care facilities.
Two years later she was appointed manager of the Denver Department of Health and Welfare, donating her salary of $4,000 to the University of Colorado Medical School for Research. She became chair of Denver's newly formed Board of Health and Hospitals in 1951 and served for two years in that position. Her unflagging enthusiasm for public health issues bore significant fruit. A Rocky Mountain News reporter stated that "Dr. Sabin … was the force and spirit behind the Tri-County chest X-ray campaign" that contributed to cutting the death rate from tuberculosis by 50 percent in Denver in just two years.
But Sabin's enormous reserve of energy flagged under the strain of caring for her ailing sister. While recovering from her own illness, Sabin sat down to watch a World Series game on October 3, 1953, in which her favorite team, the Brooklyn Dodgers, were playing. She died of a heart attack before the game was over.
The state of Colorado gave Sabin a final posthumous honor by installing a bronze statue of her in the National Statuary Hall in the Capitol in Washington, D.C., where each state is permitted to honor two of its most revered citizens. Upon her death, as quoted in Biographical Memoirs, the Denver Post called her the "First Lady of American Science." Sabin's philosophy of life and work might be best summed up by words attributed to Leonardo da Vinci, with which she chose to represent herself on bookplates: "Thou, O God, dost sell unto us all good things at the price of labour."
Further Reading on Florence Rena Sabin
Bluemel, Elinor, Florence Sabin: Colorado Woman of the Century, University of Colorado Press, 1959.
Kronstadt, Janet, Florence Sabin, Chelsea House, 1990.
McMaster, Philip D. and Michael Heidelberger, "Florence Rena Sabin," in Biographical Memoirs, Columbia University Press, 1960.
Yost, Edna, American Women of Science, Frederick A. Stokes, 1943.
Rocky Mountain News (Denver, CO), March 1, 1951.