Museum Boerhaave in Leiden is temporarily closed due to a major renovation. However, the largest part of the collection cannot be found in the museum, but in the depot. NEMO Kennislink was allowed to browse the unimaginably large collection.
Microscopes of all shapes and sizes. Anatomical models of papier-mâché. The prototype of the first artificial kidney. Antique surgical instruments. Wonderfully shaped chemical glassware. Test models of a telephone exchange. Wax models of eye diseases. Mathematical formulas executed in stone. A machine for cutting brains into thin slices. Historic physiotherapy devices.
You can't imagine whether it is in the depot of Museum Boerhaave in Leiden, the Rijksmuseum for the history of natural sciences and medicine. With the head of restoration Paul Steenhorst as an enthusiastic guide, NEMO Kennislink wandered past some of the more than forty thousand objects that the museum now manages. Or better:object numbers. A doctor's bag full of instruments has one object number, but of course contains many more objects.
“The collection is still growing,” says Steenhorst. “When I started here thirty years ago, there were eighteen thousand object numbers. Nothing really ever goes away. We just received another two-ton telescope.” Where does he leave such a huge monster? “Well, that's a bit subjective, but if the object is bigger than myself or if several people are needed to lift it, then it goes to our large warehouse in Alphen aan de Rijn.”
Separated head
The museum is continuously offered items. Often from companies, universities or hospitals. “We regularly receive complete collections. For example, from Shell when the Royal Shell Laboratory in Amsterdam was closed. We also received a large collection from Unilever.” But there are also private donations and that sometimes leads to bizarre situations. “Once we had a teacher at the desk with a cut head in a plastic bag. He had found it in the attic of his school.” After consultation with the ethical committees of ethnological museums, it was decided to include the head in the collections.
Steenhorst does not interfere with the selection of objects. “That is what the scientific staff of the museum judges. They select what suits the collection.” Once selected, the object will first go into quarantine. Steenhorst wants to make sure that he does not ingest woodworm, longhorn beetle, fungi or other misery. “I once received a box that, according to the donor, was completely clean. But I didn't trust it and wrapped the coffin in plastic and put it in the quarantine depot. Very quickly the woodworm had eaten not only through the plastic, but also through the shelves of the cupboard. In the end I had to demolish the entire closet.”
Another threat is radioactivity. That's why the Geiger counter, a detector for radioactivity, goes over everything. “In my early years here, we bought it. When we started working on that, it turned out that something really sparkled in the collection.” Of course, these objects have now been stored in a secure manner.
Traces of use
And then? How do you treat a scientific instrument? In the case of art or archaeological finds, the restorers only restore where it is necessary to prevent further decay. Does that also apply to the restoration of scientific objects? In the end, it's all about function. What if it doesn't work anymore? Steenhorst:“For me, the life course of an object is also very interesting and traces of use or replacement are worth preserving. A good restorer can choose the period in the life course to which he or she will restore, and that is determined in consultation with the scientist who is researching the object. I don't think everything should go back to its original state. Our vision is that you should do as little as possible to an object.” If the object no longer works, no problem, as long as it is presentable. Steenhorst and his colleagues make demonstration models to show the operation to the public.
What if you don't understand how it worked? Or if you don't know what it was once intended for. Steenhorst laughs. “That happens more often, there are plenty of things here that we don't yet know exactly how it works or what it's for.” The best way to find out more about an object is just to get to grips with it. Or try to copy it.
Meanwhile, we walk at a brisk pace through the enormous building, which also houses the Naturalis depots and the National Museum of Antiquities. We go from room to room, filled with endless collections of 'things'. Steenhorst opens drawers and boxes and everything has a story. He picks up a flat blue box that resembles a gift box. “I think this is very beautiful. It comes from the Shell collection. Now we say 'to measure is to know', but in the past comparing was more important than measuring." The box contains a row of glass tubes with transparent liquid and an air bubble that moves through the tubes at different speeds when you move the box. A measure of the viscosity (viscosity) of liquids! “Exactly, here on the right-hand side you put the tube with the liquid you want to measure and then you see which reference tube the speed corresponds to.”
Tin Plague
While walking, it becomes apparent how diverse the collection is and with it the problems that a restorer like Steenhorst has to deal with. For example, we pass Leidse Flessen, wide glass bottles covered with a thin layer of tin. A Leiden Bottle is a capacitor:you can store electrical charge in it. The layer of tin looks like peeling paint. “These bottles suffer from tin plague,” Steenhorst explains. “By exposure to high humidity you get corrosion of the tin layer. It then falls apart like candy.”
In addition to tin plague, there are many ailments that plague the objects. Glass can suffer from 'glass disease', the glaze layer on ceramics can crack, paper can suffer from fungi and so on. Not to mention the modern plastic objects. “Plastic dries out and crumbles or, on the contrary, it becomes shapeless and limp. Those materials are a disaster for a restorer.” Incidentally, he does not deal with all these problems himself. He brings in external experts for specialist projects such as the restoration of ceramics, glass or paper.
Meanwhile, we have arrived at our last stop:the workshop. We see various lathes for metalworking, work tables full of tools and colleague Auke who specializes in wood restoration. Steenhorst is in charge of the metal objects and technical instruments. He learned the trade at the Leiden instrument makers school and is a real artisan restorer. “In the past you didn't have a restorer in museums like this, but just a handy guy who could fix things.” He still fixes things, but his time is no longer fully spent on restoring. Many tasks have been added. For example, guiding students. “We always have students here for internships. From the Leiden instrument makers school, but also from all kinds of other courses and they come from everywhere.”
Craft Replicas
In one corner we see a modern research set-up. Scientific research also takes place in the restoration studio. It is the field of work of Tiemen Cocquyt who here, funded by an NWO Museum grant, researches seventeenth and eighteenth century optical instruments. He is particularly interested in the grinding techniques used for lenses in microscopes and telescopes.
A surprising task of Steenhorst is the new production of objects. Such as demonstration models:copies of instruments from the collection with which you can show how the original works. But they also do commercial production here. Accurate replicas of Antoni van Leeuwenhoek's first microscopes are for sale in the shop of Museum Boerhaave. Made by Paul Steenhorst, who can express his obvious love for the craft in this. He shows a few 'Van Leeuwenhoekjes'. “The great thing about making copies by hand is that you can always see how skilled instrument makers used to be. I would also like to drop that penny among our students and the public.”
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Model eye diseases
Restorer Paul Steenhorst of Museum Boerhaave gives Kennislink a tour of the immense depot. Here he shows an antique plaster model with various eye diseases. The eyes are imitated down to the smallest detail. The model comes from Paris and was made by Félix Thibert between 1830 and 1840.
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Artificial kidney A.E.G.
Internist Willem Kolff developed the artificial kidney just after the Second World War. In the depot of Boerhaave is one of the first copies, made in 1946 by A.E.G. (Allgemeine Electric Gesellschaft). In this time of scarcity, use has largely been made of already available equipment:the membrane is wrapped with cheesecloth and is placed in a children's pool, placed on a hospital cart.
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Microscopes
After the invention of the microscope by Anthonie van Leeuwenhoek in the 17th century, the device developed rapidly. The microscope was popular not only among scientists but also among citizens. The rich that is, because these exclusive models with rye, shark or turtle skin were not cheap. In the 19th century, an evening of 'small binoculars' was a popular pastime and the owners were more than happy to impress their guests with these beautiful binoculars.
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Paper mache models
Before we had plastic, making life-size models was a very labour-intensive and precise job. The muscles and veins on this detailed papier-mâché human and dove have been carefully painted by hand. The unique model of the woman was created in 1858 by the French physician and anatomist Louis Auzoux. Boerhaave has 72 models of his in the collection, including the pigeon.
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Zander Physiotherapy device
At the end of the 19th century, the Swede Gustav Zander developed a whole range of devices for physiotherapy. The exercises that the patients had to do were based on the way they moved during that period. This device simulates a horse riding.
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Obstetrician Manikin
A cloth manikin of the uterus and birth canal, including a baby. The future midwives of the 19th century learned their trade on this half-female replica.
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Plaster models gas laws
The famous scientist Heike Kamerlingh Onnes did some experiments in his Leiden laboratory. He had these three-dimensional plaster surfaces made in 1898 to illustrate the gas laws.
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Delft blue apothecary jar
One of the many Delft blue apothecary jars in the depot. The Delft pottery factory De Paauw produced the pot around 1700-1750. This pot has had absinthe, which has damaged the stone. Hence the warning note:'Active salt! Fragile'
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Lion's Corner
Antoni van Leeuwenhoek's microscope does not resemble our current microscope at all. How does the little device actually work? This video from Museum Boerhaave shows it.