Antonie van Leeuwenhoek was a wealthy cloth merchant who lived in the city of Delft, in the Netherlands, from 1632 to 1723. He is best known for his pioneering work on microscopy: from 1673 onwards he created as many as 500 microscopes and from these made numerous significant discoveries. This included determining the existence of single-celled organisms, a discovery that ironically brought his scientific credibility into question for some time.
The success of these microscopes can be attributed to many things, but a number of technical matters stand out. First, his microscopes relied on a single lens. Compound microscopes (those with more than one lens in the light path) theoretically provide better resolution, but they are also much more technically challenging to fabricate. As well, Leeuwenhoek devised a relatively simple means to produce his single lens. In particular, his methodology appears to have reduced the need for precise grinding techniques, and grinding was a laborious and technically difficult process.
The few examples of Leeuwenhoek’s microscopes that remain today are elegant creations of brass or silver with many working parts. Although much less complex than modern microscopes, replicas of metal with the same working features are challenging to build and require some skill with a small number of tools (Figure 1-1). However, the basic functional aspects of the design and lens production can be replicated in a few minutes, using a few simple raw ingredients.
Following the steps available here, you will be able to construct a working microscope using van Leeuwenhoek’s general design and method of lens production. From this, you can then measure the size of the lens you make, and calculate its magnification. Lenses capable of 100X to 200X magnification are not too difficult to produce, and this article will also suggest and illustrate a number of interesting samples one can examine.
It’s amazing to consider how we often take microscopy for granted in this day and age. However, when you use the microscope you build yourself, try to imagine what it must have been like to peer through one of these creations and discover a completely unknown realm of life, because your instrument will reproduce the microbial world as it would have looked like using the technology of the seventeenth century.
The purpose of this guide is not to create a working replica of a Leeuwenhoek microscope. There are already detailed instructions available on this, in particular I recommend Alan Shinn’s instructions (see below). However, in the process of building such a replica from original documents, it became clear that it would be possible to create a microscope of similar design and power using only inexpensive materials that were easy to work with, and almost no tools. In a class environment this process has been successful with high school students as well as advanced undergraduates.
For further information on making more realistic replicas of Leeuwenhoek microscopes there are several sources, and I particularly recommend Alan Shinn’s site. For additional information on creating various types of lenses, see Baker, RC 1991 Science PROBE (April) pp. 53-62. For the method described below to calculate the power of the lens, see part 4 of John Davis’ article. All of these contain numerous other references of interest.