March 26, 2018 | David F. Coppedge

Neutron Imaging Solves Mystery of Leeuwenhoek’s Microscopes

It’s been 300 years, and scientists are just now figuring out how Antony van Leeuwenhoek was able to grind microscope lenses of superior quality.

Leeuwenhoek did it by himself. His microscopes were so good, some historians have questioned how the cloth merchant could have created lenses able to image bacteria. Now, the Delft Institute of Technology, says, has proved he was able to grind his superior lenses without help from others.

Researchers from TU Delft and Rijksmuseum Boerhaave have solved an age-old mystery surrounding Antonie van Leeuwenhoek’s microscopes. A unique collaboration at the interface between culture and science has proved conclusively that the linen trader and amateur scholar from Delft ground and used his own thin lenses.

Considering the unrivaled quality of the microscopic images produced by Van Leeuwenhoek, this was always thought to be practically impossible. The prevailing view was that grinding small lenses of such high quality by hand was simply a bridge too far. A new research method helped to solve the mystery—namely, using a neutron bundle from the TU Delft research reactor.

Graphic by J Beverly Greene for CEH. All rights reserved.

Leeuwenhoek exceeded the magnification of his contemporaries’ magnifying lenses (300x) by tenfold. “How he managed this feat remained a mystery up until now,” the researchers in his hometown say.  The reason it has taken so long to solve the mystery is that there are only 11 of his microscopes left in existence, and they are too valuable to take apart. Scientists needed a non-invasive method to study the interior design of his craftsmanship, and they found one.

The mystery of the Leeuwenhoek lens was solved thanks to non-invasive neutron tomography, which made it possible to create an image of the inside of the microscope without having to break it open. The Reactor Institute Delft is home to a new instrument that operates using this technology. “Tomography involves rotating an object in a neutron bundle in front of a camera, and photographs are taken as the object rotates,” explains Lambert van Eijck, a TU Delft researcher. “Neutrons are uncharged particles and pass through metal – in contrast to X-rays, for example. After you have rotated the object through 180 degrees, you can use the collection of 2-D images to construct a 3-D image of the object on the computer.”

The work proves that Leeuwenhoek did not use glass-blowing or other exotic techniques. He was just an exceptionally skilled grinder of glass lenses. What he saw through those tiny lenses would change the world:

The Leeuwenhoek microscope was recently chosen as a Dutch showpiece in the design category on a national television programme. Tiemen Cocquyt says, “The instrument opened new worlds, and Van Leeuwenhoek was the first to view bacteria, sperm cells and blood cells, discoveries that he published in the journal of the British Royal Society.” With his simple, yet extremely specialised microscope, Van Leeuwenhoek saw what nobody had seen before – or even could have seen. It was another 150 years before others succeeded in building a microscope capable of revealing more.

Future imaging with gamma ray spectroscopy might reveal the ingredients of the glass he used, the article says. Neutrons temporarily make the material radioactive. By watching how the radioactivity decays, scientists can learn about the elements in the glass. Research into the Leeuwenhoek mystery continues.

See our CEH biography of Antony van Leeuwenhoek, a Christian who believed God created the tiny creatures he saw. His delight in studying them, proving that belief in God as Creator is not a science stopper, but a science motivator. His main problem was in getting the skeptics of his day to believe that such wonders really existed. And when they tried to say “stuff happens” to explain them (i.e., spontaneous generation), he proved that living things always came from prior living things. Evolutionists today have not learnt the lesson of Leeuwenhoek.




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