Jan Swammerdam

Dutch scientist and naturalist

• Born: February 12, 1637
• Birthplace: Amsterdam, Holland, United Provinces (now in the Netherlands)
• Died: February 17, 1680
• Place of death: Amsterdam, Holland, United Provinces (now in the Netherlands)

Swammerdam was among the earliest scientists to apply microscopic techniques to the study of anatomy and physiology in diverse organisms, ranging from insects to human beings. His work marked the beginning of the scientific study of insects, and he is most likely the first to observe red blood cells.

Early Life

Jan Swammerdam (yahn SVAHM-ehr-dahm) was the son of Jan Jacobszoon Swammerdam, an apothecary and naturalist, and Barentje Corver. Swammerdam’s father wanted his son to spend his life in service to the Church, and the younger Jan was tutored in both Latin and Greek with that profession in mind. However, Jan developed a strong interest in the sciences, and he was able to convince his father that a career in medicine was closer to his interests.

As a youth, Jan learned science by arranging and cataloging his father’s collections of natural specimens brought from throughout the world, eventually producing a museum-quality selection considered one of the finest in the country. Jan’s interests, which included the catching and study of insects, led him to discoveries of insect life cycles, studies that were considered among the most complete of the time. It has been suggested that during these early years, Jan might have met Antoni van Leeuwenhoek , the Dutch lensmaker credited with developing the first “modern” microscope, when Leeuwenhoek visited Jan’s father. No mention of this is made in any original sources, and the story cannot be otherwise confirmed.

Swammerdam’s life as a student of medicine began in 1661, as he studied both in Amsterdam and Leiden under the tutelage of distinguished professors such as Gerard Blaes; Johannes van Horne, the anatomist who discovered the role of the thoracic duct; and Regnier de Graaf, a fellow student later known for his studies of female reproductive organs. Swammerdam became known in the school for his abilities at dissection. In 1664, while still a student, Swammerdam discovered the presence of valves in lymphatic vessels (now called Swammerdam valves). His study of respiration became the basis for his doctoral thesis, in which he concluded that inhaled air passed through the windpipe into the lungs, and from there traveled through vessels into the heart. He also suggested that air contains a volatile element of some sort that passes into the lungs and, eventually, into the heart. In February, 1667, Swammerdam was awarded his doctoral degree.

Life’s Work

Though his father had hoped he would develop a medical practice, the younger Swammerdam’s interests were primarily in research. Consequently, he devoted all of his time to that endeavor and created a rift with his father, which resulted in the loss of his financial support. Though Swammerdam’s father died in 1675, the years of deprivation, coupled with long hours at work, eventually eroded the younger Swammerdam’s health. In his later years, he became a hypochondriac and a follower of mysticism.

Swammerdam’s studies extended through a large number of scientific fields. While visiting Paris in 1665, he met and developed a friendship with Melchisedec Thévenot, a French patron of the arts and a diplomat, who encouraged Swammerdam to specialize in areas of reproduction and development. Much of his research time was spent in the study of insects, and it involved extensive use of the newly developed microscopes. His inspiration was found in a 1669 monograph on silkworms published by the Italian anatomist and botanistMarcello Malpighi and sent to Swammerdam by Thévenot. Swammerdam’s publication of this work, Historia insectorum generalis (1669; general treatise on insects), marked the beginning of the scientific study of insects. Swammerdam classified insects into four “orders,” based primarily on their processes of development. He noted the various stages in their life cycles, a process known as metamorphosis. He also determined that what had been called a “king” bee was actually a female bee. Though his classification scheme has since been modified, three of his orders are still in use today.

Swammerdam is frequently credited with the discovery of red blood cells. William Harvey had proposed a role for the circulatory system earlier in the century but had not actually observed blood capillaries; contemporaries such as Malpighi reported capillaries in mesenteric tissue and had even observed blood corpuscles, mistaking them for fat globules. In his dissections of the frog, probably in the period between 1658 and 1665 (the precise date is unknown), Swammerdam noted the presence of “orbicular particles,” describing them as regular flattened ovals that slowly moved through the capillaries. He also reported blood that appeared “like cow’s milk” in his dissection of the louse, most likely an observation of white blood cells; they were not identified as such, however.

Even while carrying out investigations on insects, Swammerdam continued his study of anatomy, including the dissection of fish. Also, he noted the presence of ducts in humans that passed from the pancreas into its intestine. He collected pancreatic juice and sent it to colleagues for subsequent study.

Swammerdam never practiced medicine, but he did participate in dissections and medical examinations of patients at Amsterdam Hospital. In conjunction with his colleague Justus Schrader, a physician at the hospital, Swammerdam described the anatomy of a hernia as a blind sac originating in the peritoneum and extending into the scrotum (c. 1674). By inflating the sac with a tube, Swammerdam demonstrated it was closed on one end. His work and subsequent depictions through illustrations became important facets in understanding the nature of hernias. The significance of this work in part was its refutation of the belief that hernias were the result of the rupture, rather than an extension, of the peritoneum.

Swammerdam’s work also extended into the area of human reproduction. While still a student, he studied the anatomy of uterine vessels and illustrated the vessels of the uterus and the ovaries. He isolated human eggs, describing them as being analogous to those from birds, and also described sperm tubes found within the male testis, noting that penile erection is the result of the movement of blood into the organ.

Swammerdam spent a portion of his last years in the study of religious mysticism. Returning to science about 1676, he attempted to compile his studies into one massive work. The loss of support from his father and the subsequent death of the elder, however, left Swammerdam without funds. He was forced to sell his father’s museum collections. Weakened by malaria, Swammerdam died in February, 1680.

Much of Swammerdam’s scientific work was published posthumously as the Bybel der naturre (1737-1738) by the Dutch physician Hermann Boerhaave. In 1758, it was published in English as the Book of Nature: Or, The History of Insects . The two-volume manuscript includes more than five hundred illustrations from Swammerdam’s work.

Significance

Considering the diverse range of organisms he studied, Swammerdam could arguably be called the first scientist to develop the field of comparative anatomy as well as entomology. While Leeuwenhoek had invented the first modern microscope, Swammerdam was able to apply the technology in the study of a variety of subjects as diverse as blood flow, the lymphatic system, and the life cycles of insects.

When Swammerdam began his work, science was dominated by the teachings of the Greek philosopher Aristotle, whose philosophy was based on deductive reasoning and speculation; the structure of an organism was determined in part by its functions, and organisms were placed on a continuum that led to increasing perfection (for example, humans). Swammerdam preferred to base his conclusions on his own research. He also believed that the transmission of knowledge transcended politics, as illustrated by his submission of work on the human ovary to the Royal Society of London, despite the ongoing war that had been raging between the Dutch and British.

One could also argue that his study of insect metamorphosis, the change from one form to another during the life cycle of the organism, provided refutation of the idea that creatures can change from one type into another. Eventually, he applied this information into the earliest classification scheme for these organisms, while at the same time provided ammunition for those opposing the notion of spontaneous generation. Swammerdam’s contributions to biology thus encompassed a range far broader than that developed by contemporaries of the period.

Bibliography

Boorstin, Daniel. The Discoverers. New York: H. N. Abrams, 1991. A classic history of science from the perspective of scientific researchers, first published in 1983. Passing reference is made to the work of Swammerdam, and emphasis is placed on new scientific thought that often opposes prevailing ideas in the sciences.

Fournier, Marian. The Fabric of Life: Microscopy in the Seventeenth Century. Baltimore, Md.: Johns Hopkins University Press, 1996. Examines the reasons for the microscope’s appearance and eventual eclipse in the seventeenth century.

Huerta, Robert D. Giants of Delft: Johannes Vermeer and the Natural Philosophers, the Parallel Search for Knowledge During the Age of Discovery. Lewisburg, Pa.: Bucknell University Press, 2003. Although this book focuses on Dutch artist Vermeer’s perception of the world, it describes how that perception was influenced by the microscope and other discoveries in the science of optics. Several chapters describe how scientists created a “more optical” way of viewing the world.

McClellan, James, and Harold Dorn. Science and Technology in World History: An Introduction. Baltimore, Md.: Johns Hopkins University Press, 1999. The authors present a history of science and technology and explore the development of the microscope and Swammerdam’s application of the instrument.

Oster, Malcolm. Science in Europe, 1500-1800: A Secondary Source Reader. New York: Palgrave, 2002. A relatively brief account of scientific endeavors as carried out during this era. Swammerdam’s work is placed in historical context.

Ruestow, Edward G. The Microscope in the Dutch Republic: The Shaping of Discovery. New York: Cambridge University Press, 1996. The author traces the development of microscopy from its origins in the seventeenth century, as well as its early applications. One chapter is devoted to the work of Swammerdam. Extensively illustrated.

Schierbeek, Abraham. Jan Swammerdam: His Life and Works. Amsterdam: Swets & Zeitlinger, 1967. In addition to a brief biography of Swammerdam, the author provides a systematic summary of Swammerdam’s work, including excerpts from notable books and manuscripts. Also included is a bibliography of Swammerdam’s known and assumed works.

Swammerdam, John. The Book of Nature. Translated by Thomas Flloyd. 1758. Reprint. New York: Arno Press, 1978. A modern reprint of Swammerdam’s influential work. Includes illustrations and an index.

‗‗‗‗‗‗‗. The Letters of Jan Swammerdam to Melchisedec Thévenot. Translated by G. A. Lindeboom. Amsterdam: Swets & Zeitlinger, 1975. A collection of correspondence between Swammerdam and arts patron Thévenot, with letters in English, Dutch, French, and Latin. Includes illustrations and indexes.