Johannes Swammerdam’s Scientific Images (I)

By Eric Jorink

Fig. 1: Drawing by Johannes Swammerdam, Royal Society Archives LBO/6/58 © Royal Society

On 4 March 1673, Johannes Swammerdam sent a letter to Henry Oldenburg, including these images (fig. 1). Only an abstract of the letter appeared in the Philosophical Transactions (19 May 1673, page 6041), without including what was basically the point of the message: a visual report of observations of the pulmonary arteries of a frog, and of the genital system of the horn-noosed beetle. As a biographer of Swammerdam, I find these images fascinating, both for their intrinsic quality, as for the fact that they are a nice point of departure for some thoughts on the role of the visual in early modern scientific culture.

Like Robert Hooke, Swammerdam was a skilled draftsman. During his years as a student in Leiden (1661-1667) he did pioneering research on insects, toads and other forms of low life. Swammerdam maintained that all creatures, great and small, obeyed the same laws of nature. He rejected the theory of spontaneous generation, according to which insects were devoid of an internal anatomy and had their origin in decaying flesh or plants.

Fig 2: The water gnat, as depicted by Robert Hooke in Micrographia (1665). © Royal Society
Fig 2: The water-gnat, as depicted by Robert Hooke in Micrographia (1665). © Royal Society
Fig. 3: the water gnat, as depicted by Robert Hooke in Micrographia (1665) and Johannes Swammerdam, Historia generalis insectorum (1669). Swammerdam depicts the creature in its context, both life sized and enlarged (ca. 15 times).
Fig. 3: the water-gnat, as depicted Johannes Swammerdam, Historia generalis insectorum (1669). Swammerdam depicts the creature in its context, both life sized and enlarged (ca. 15 times). © University Library Leiden

Swammerdam considered it his duty to point to the marvels of God’s creation. Swammerdam was very much aware of his talent as an anatomist and draftsman. He applauded the publication of Hooke’s Micrographia (1665), Redi’s Esperienze intorno alla generazione degl’insetti (1668) and Malpighi’s De Bombyce (published by the Royal Society in 1669) and considered them as allies in his campaign against spontaneous generation.

In his Historia insectorum generalis (1669) Swammerdam demonstrated that all insects come from eggs, and all go through a stage-like development. Occasionally, he also went into a visual dialogue with Hooke (figs 2 and 3). Whereas the latter famously had represented the alien micro-world with no visual clues of the absolute size and context of the objects portrayed, Swammerdam employed a technique in which each creature was represented both life-size, and magnified. The microscope was only used occasionally. Graphically, he showed the uniformity of nature, pointing at similarities between the development of an insect, frog and carnation (figs 4 and 5).

Figs 4 and 5; the stage-like development of the louse; and the frog and carnation as depicted in Johannes Swammerdam, Historia generalis insectorum (1669). Visually, the uniformity of nature is demonstrated. Each creature is depicted life sized, and enlarged in various stages of development.
Figs 4 and 5: The stage-like development of the louse; and the frog and carnation as depicted in Johannes Swammerdam, Historia generalis insectorum (1669). Visually, the uniformity of nature is demonstrated. Each creature is depicted life sized, and enlarged in various stages of development. © University Library Leiden
Fig. 5. © University Library Leiden

In Historia insectorum Swammerdam concentrated on the outward appearance of insects. Inspired by the work of Malpighi from 1670 he now focused on anatomizing and using the microscope more intensively. Studying and representing the inner parts of these tiny creatures required new visual techniques. Since Swammerdam observed what no one before him had seen, he had to train his eye with regard to the observations, and invent ways to represent them. Without external aid, showing the strange and previously unseen forms of isolated organs of a creature would make no sense.

The images Swammerdam sent to Oldenburg could be seen as experiments in form. Compared to the visual strategy he previously used, Swammerdam was now both zooming in and zooming out. To make an easy start: the creature depicted in figure V in the right lower corner marked A (see fig. 1 above) is easily recognizable as a nose-horned beetle (depicted at life size). The drawing is deceptively simple, but shows Swammerdam’s talent to represent the creature with just a few well-chosen lines and brushes of ink. Swammerdam deeply admired the work of artist Joris Hoefnagel (1542-1600), who at the end of the sixteenth century had made pioneering watercolors of all kinds of insects. We could read Swammerdam’s sketch as a self-aware introduction to the beholder – see how easily I can draw things familiar to you; you can also trust me when I show you places and things unknown to you. Later drawings by Swammerdam of the nose-horned beetle (fig. 5) are much more elaborated, and can be seen as explicit references not only to Hoefnagel but also to the works of art by Jacques de Gheyn (1565-1629) and even Albrecht Dürer.

Fig. 6: Some beetles; the male genitals system of the nose-horned beetle (fig. viii). Swammerdam drew this in 1678 for his Biblia Naturae; the manuscript, now kept in Leiden university Library, was only published in 1737. Leiden, UB, BPL 126B, fol. 31r. © University Library Leiden

By now, we should refer to the letter. By focusing on the creature’s inner parts, Swammerdam uses the strategy of both mapmakers and earlier anatomists: the legend. He writes: ‘Figure V expresses to the life (‘ad vivum exprimit’) the genitalia of the horn-nosed beetle. A the beetle, B the horny part of the penis, C the place from which the penis protrudes when erect….’ Etcetera. What we see are interior details: strangely shaped organs, curled lines, flower-shaped structures. Using a legend is a successful strategy here, and perhaps the only workable way in representing the previously unknown. Moreover, as Swammerdam occasionally stressed to his readers, the slightly stylized drawings also helped the observer who for the first time would enter this unknown territory to discern and identify the organs in there. Swammerdam also employs this strategy in the Figures I-IV (fig. 1), where he illustrates the passage in which he explains in painstaking detail the pulmonary artery system of the frog. These drawings are the few by Swammerdam I know of in which color is used. This had a practical reason: the drawings represent, as Swammerdam put it, ‘graphically’ (‘graphice exprimit’) how the structure within the lungs had been made visible by injecting colored wax. Hence, what we see is a representation of a preparation interacting with a text.

The point is, of course, that without the accompanying letter, the images become meaningless, and vice versa. Some of Swammerdam’s letters and images are still at the archives of the Royal Society (now separated, to be sure). They remind us that in the scientific culture of the 1670s the boundaries between words and images, and between science and art, were still rather fluent ones.

An Image Interview with Ian Lawson

Louse from Robert Hooke, Micrographia, 1665


Can you tell us briefly about yourself and your background?

Ian Lawson, historian and philosopher of early modern science. I recently finished a PhD in the Unit for History and Philosophy of Science at the University of Sydney, about the seventeenth century natural philosopher Robert Hooke and his work with early microscopes. I am interested in his fiddly daily activities with the instruments and how they are interpreted and seen, not only in terms of the work he produced but the social position of such work. Now I’m visiting the Max Planck Institut für Wissenschaftgeschichte in Berlin, and planning out a new project about the optical instruments which became fashionable in Enlightenment Europe.

Which picture have you chosen, and what does it show? 

This is Hooke’s famous louse from his 1665 book Micrographia. Hooke drew the images for the book himself. He was an apprentice, for a while, to the portrait painter Peter Lely, and became an accomplished draftsman. The newly-founded Royal Society brought Hooke to London from Oxford for the express purpose of drawing insects, observed through a microscope, as gifts for King Charles II. The project morphed into a book, printed with the money and the blessing of the Royal Society, illustrated with 38 such pictures. This is one of the last, and folds out to the size of a small cat. It was a book which transformed things so small that no one had ever seen them before into household objects.

(There’s a video of William Poole talking about this aspect of the book and showing the page containing the flea, which gives a good impression of it’s size and heft. The book itself is on Project Gutenberg.)

Why have you chosen this image? 

It’s an impressive image considered solely as an early modern engraving, and a masterpiece of natural historical drawing (though it’s not my favourite drawing from Micrographia to look at). What grabs me about it is that it’s not a drawing of only a louse, but of Hooke as well. It’s his hair the creature is gripping, and his blood that colours the shapes in its abdomen. The picture relates the details of a louse, but it also represents, in a more abstract sense, a particular relationship that Hooke had with the world around him. In the blurb accompanying the image, he talks excitedly about keeping the louse in a jar, and starving it so when it’s let out it’ll feast on him and he can watch it swell up like a balloon.

Not everyone thought this to be an appropriate way to relate to a louse. (It is not, after all, the kind of creature that many people celebrate. Think about the creepy tenor of John Donne’s ‘The Flea’ or, later, Robbie Burns’ outrage at watching a louse keep polite company in ‘To a Louse’). Margaret Cavendish, for example, a keen natural philosopher and the Dutchess of Newcastle, wondered what beggars would think about this drawing. A better reason to examine these critters would be to show how to avoid their bites! She thought Hooke’s morbid interest was useless at best, and drawing such beguiling pictures risked distracting people from research that was genuinely socially useful.

How does this image resonate with you in the context of your work or research?

I’m interested in how new conceptions of nature and new methods of investigation became fashionable and socially popular. Why did Hooke, but not others, think it was interesting or appropriate to display a louse in this way? It’s funny now to think of this image or the microscope as controversial, but in early modern Europe it sure had it’s critics, both in popular and philosophical writing. Cavendish’s worry was, partly, the perfectly reasonable (and still current) one that educated and wealthy people could better spend their time trying to solve real problems. Considering the louse not only as a new kind of natural historical illustration but as a symbol of this disagreement makes it interesting to track the following popularity of the microscope. What did it mean that there was a fashion for them in the following century or so, and how much did their fashionability influence scientists’ opinions of the instrument?

What significance does the image have for the historical understanding of the relationship between knowledge-making and image-making?

Hooke also gave public lectures and demonstrated instruments in front of audiences, but there’s a sense in which the knowledge in Micrographia had to be a printed book. Hooke’s images, for all their naturalism, are not really of anything that he actually saw, or of anything directly visible through his lenses. He emphasises in the book that he drew pictures only after several examinations of an object, as he also lets on when he talks about watching the louse feed from him. He saw it in various shapes, positions, and more or less well-fed. His wizardry with lenses and light created only temporary glimpses at ever-changing objects, so image making was an essential part of knowledge making in that drafting, engraving, and printing also ‘fixes’ the knowledge into a stable form that can be returned to and re-examined.

What significance does this image have in the context of your field or work?

It shows, I think, what was essentially a new methodology in natural philosophy. Hooke loved that he could see through the louse to its insides. Several of his observations make this point, and he argued for his whole life that microscopes were the best method we had of discovering the ‘inner’ or ‘secret’ workings of things. To see inside objects without one, one would have to make incisions like an anatomist or dissolve things in acid or fire like an alchemist. With a microscope, he wrote, he could peek “through these delicate and pellucid teguments of the bodies of Insects” and, like a voyeur, watch Nature in action: “quietly peep in at the windows, without frighting her out of her usual byas” (Micrographia, observation 43). It’s an important and poetic moment in the history of natural scientific methodology. For one, it’s definitely in line with the fashion in Hooke’s time for viewing the world mechanistically, as if he would see the clockwork inside insects that made them tick. But it’s also vaguely democratic, in that doing so does not require a furnace or any other particularly spectacular equipment. It’s both a recognition that there’s more to be discovered about the world than is readily apparent, and that the method by which to do so is not hugely inaccessible.

Learning to see

By Sietske Fransen

Drawing of a cross-section of a worm, by Sietske
Drawing of a cross-section of a worm, by Sietske

At the age of 18 I started my undergraduate degree. I had wanted to become a gynaecologist for many years and had therefore signed up to study Medicine at the University of Nijmegen (in the Netherlands). However, about six months before the end of high school, I realised I was more interested in how things work inside bodies, and why people get ill, than in how to deal with diseases at the patient’s end. So, I changed my course to Biology at Utrecht University, to learn all about the workings of living organisms.

Drawing of a locust, by Sietske
Drawing of a locust, by Sietske

At the time, the first year of Biology was build up from the smallest to the largest systems, meaning that we started with Organic Chemistry in September and ended with Ecology at the end of our first year. And over the last four months of year one, we also had the courses Zoology I & II. In my memory (I might be wrong…) this included “practica” on every afternoon from Tuesday till Friday.

The main thing we did during those practical hours was looking at organisms and their anatomies, with the naked eye and the microscope. Dissecting all types of small animals (from lugworms to rats) was extremely informative, however, most of the specimens would come on pre-prepared microscope slides. Looking at these slides we could observe all the different types of tissues and cells in the different organisms of the animal kingdom. In other parts of our course we would be reading or hearing about them, but actually seeing things ourselves was a very important part of our education.

Drawing of a squid, by Sietske
Drawing of a squid, by Sietske

At the time, the ordeal felt like a critique of my drawing skills, but I now understand that I was not taught to draw (nor expected to draw well), but rather educated to observe and see. To be able to distinguish the different organs in a worm, a squid, and a locust, is one thing. However, the process of distinguishing different cell types under a microscope, is quite another. Hence, our long afternoons of dissecting, microscopy and drawing, were all about learning to see.

Malpighian corpuscles, drawn by Sietske
Malpighian corpuscles, drawn by Sietske

This has become all the more apparent to me since I started working on the Making Visible project. I have begun to admire even more the men who started using microscopes and telescopes in the seventeenth century and described what they saw. The things they saw through these devices had never been seen before by them or any previous philosopher. No text book would help them in the right direction, for them no lecturer who spoke about that exact object that same morning. This makes it all the more surprising then to find their names in modern biology books, such as the renal or Malpighian corpuscle (a part of the kidney), which, three hundred years after Malpighi’s first observation, I still had to draw at university.

With this blog post I am not getting to any answers or spectacular new observations, but rather to formulating questions which I would like investigate during the coming years of our project. I am wondering whether the seventeenth-century anatomists and microscopists were educated in drawing. Were those who took a medical degree at university or those Fellows of the Royal Society who could be described as ‘amateurs’, ‘liefhebbers’, or gentlemen, taught how to draw specimens? And did they need these artistic skills, or did they rather need an education in seeing and observing? And maybe the two are joined exercises?

Sperm drawn by Antoni van Leeuwenhoek, Letter to the Royal Society, 31 May 1678, EL/L1/36
Sperm drawn by Antoni van Leeuwenhoek, Letter to the Royal Society, 31 May 1678, EL/L1/36

Antoni van Leeuwenhoek (1632-1723), the Dutch microscopist and most prolific correspondent of the early Royal Society, did not go to university and specifically stated in his first letter to the Royal Society that he is not a draughtsman himself and that he therefore hired skilled people to draw his observations. However, some of his own drawings, such as this drawing of male sperm, do not come across as bad drawings, and in fact seem to demonstrate a certain degree of skill. Therefore, I am curious to understand more about the seventeenth-century notion of the skilled draughtsman. Also these draughtsmen had never seen the specimens under the microscope, but they were, at least according to Van Leeuwenhoek, better skilled in drawing. So what is the relation between observation and the registration of these observations, and how was a seventeenth-century “scientist” educated and prepared to do both?

By looking at Antoni van Leeuwenhoek, as well as Regnier de Graaf (1641-1673) and Jan Swammerdam (1637-1680), two other Dutch microscopists who corresponded with the Fellows of the Royal Society, I will investigate their skills in observation and drawing, and the way in which they report about their own skills in their letters. Hopefully this investigation will give us a better sense of the education Dutch anatomists and microscopists received in terms of drawing skills, and also which skills of observation they expected from their readers.