Jan Swammerdam

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Jan Swammerdam : biography

12 February 1637 – 17 February 1680

Besides Historia, he published Miraculum naturae sive uteri muliebris fabrica in 1672 and Ephemeri vita, in 1674. The latter was a study of the mayfly, written at a time when he was becoming increasingly involved in spiritual matters. The work contains long passages on the glory of the creator. His Bybel der Natuure was a collection of his papers and drawings.

Research on anatomy

Swammerdam’s illustration of a nerve-muscle preparation. He placed a frog thigh muscle in a glass syringe with a nerve protruding from a hole in the side of the container. Irritating the nerve caused the muscle to contract, but the level of the water, and thus the volume of the muscle, did not increase. Swammerdam was not a pioneer in the study of anatomy as he was in study of insects, but he nonetheless made important contributions. His use of, and experiments with, frog muscle preparations played a key role in the development of our current understanding of nerve–muscle function. The experiments introduced a new method of studying nerves, the frog nerve-muscle preparation, which was still used centuries later.

In one experiment, Swammerdam removed the heart of a frog and observed that touching certain areas of the brain caused certain muscles to contract. For Swammerdam, this was evidence that the brain, not the circulatory system, was responsible for muscle contraction.

Swammerdam played a key role in the debunking of the balloonist theory, the idea that ‘moving spirits’ are responsible for muscle contractions. The idea, supported by the Greek physician Galen, held that nerves were hollow and the movement of spirits through them propelled muscle motion. René Descartes furthered the idea by basing it on a model of hydraulics, suggesting that the spirits were analogous to fluids or gasses and calling them ‘animal spirits’. In the model, which Descartes used to explain reflexes, the spirits would flow from the ventricles of the brain, through the nerves, and to the muscles to animate the latter. According to this hypothesis, muscles would grow larger when they contract because of the animal spirits flowing into them. To test this idea, Swammerdam placed severed frog thigh muscle in an airtight syringe with a small amount of water in the tip. He could thus determine whether there was a change in the volume of the muscle when it contracted by observing a change in the level of the water (image at right). When Swammerdam caused the muscle to contract by irritating the nerve, the water level did not rise but rather was lowered by a minute amount; this showed that no air or fluid could be flowing into the muscle. Swammerdam did not believe the results of his own experiment, suggesting that they were the result of artifact. However, he concluded in his book The Book of Nature II that "motion or irritation of the nerve alone is necessary to produce muscular motion". This idea that nerve stimulation led to movement had important implications for neuroscience by putting forward the idea that behavior is based on stimuli.

Swammerdam also discovered valves in the lymphatic system, which were later dubbed Swammerdam valves.

Biography

Swammerdam was baptized on 15 February 1637 in the Oude Kerk Amsterdam. His father was an apothecary, and an amateur collector of minerals, coins, fossils, and insects from around the world. His mother Baertje Jans Corvers died in 1661. The same year, when he was 24, Swammerdam entered the University of Leiden to study medicine. After qualifying as a candidate in medicine in 1663, he left for France, spending time in Issy, Saumur and Paris with Melchisédech Thévenot. He returned to Leiden in September 1665, and earned his M.D. on February 22, 1667.

Once he left university, he spent much of his time pursuing his interest in insects. This choice caused a rift between Swammerdam and his father, who thought his son should practice medicine. The relationship between the two deteriorated; Swammerdam’s father cut off his financial support for Swammerdam’s entomological studies. As a result, Swammerdam was forced, at least occasionally, to practice medicine in order to finance his own research. He obtained leave at Amsterdam to dissect the bodies of those who died in the hospital.

From 1667 through 1674, Swammerdam continued his research and published three books. In 1675, he came under the influence of the Flemish mystic, Antoinette Bourignon, renounced his work, and decided to devote the remainder of his life to spiritual matters. Niels Stensen, a gifted anatomist, and once his co-student, invited him to work for the Duke of Tuscany, but Swammerdam refused. The grand duke of Tuscany offered 12,000 florins for Swammerdam’s collection, on condition of Swammerdam coming to Florence to continue it.

There is evidence, however, that Swammerdam did not completely give up his scientific studies. The papers, which he wished to be published posthumously, appear to have been revised during the last two years of his life.

Swammerdam died at age 43 of malaria and was buried in the Église Wallonne. In 1737–1738, a half century after his death, Herman Boerhaave translated Swammerdam’s papers into Latin and published them under the title Biblia naturae (Book of Nature). An English translation of his entomological works by T. Floyd was published in 1758. His entomological collection was divided at his death and sold in small portions. As a naturalist of his time, he has been compared with Anton Leeuwenhoek.

No authentic portrait of Jan Swammerdam is extant nowadays. The portrait shown in the header is derived from the painting The Anatomy Lesson of Dr Tulp by Rembrandt and represents the leading Amsterdam physician Hartman Hartmanzoon (1591–1659).

Contributions to methodology

Though Swammerdam’s work on insects and anatomy was significant, many current histories remember him as much for his methods and skill with microscopes as for his discoveries. He developed new techniques for examining, preserving, and dissecting specimens, including wax injection to make viewing blood vessels easier. A method he invented for the preparation of hollow human organs was later much employed in anatomy.