The History & Future of Medical Technology, Chapter 1

This post is the first in a series based on my soon-to-be published book, The History & Future of Medical Technology. Each week I’ll present highlights from one of thirteen chapters.


The Hidden World

How did the human race learn to prevent and cure diseases, repair and replace body parts, and improve the quality of life for chronic disease sufferers? The history of medicine is usually depicted as the gradual accumulation of knowledge over two thousands years punctuated in the late 20th century by the sudden convergence of biology and engineering. The problem with that narrative is that it misses two key events: an epochal invention and a scientific rebellion (discussed in chapter 2).

The microscope enabled not only modern medicine but all of the life sciences. As British biologist Brian J. Ford reminds us, the microscope has come to symbolize laboratory research.

Outsiders often do the most to prove and improve a new technology. The first person to observe microorganisms, Antony Leeuwenhoek, was a Dutch draper. Joseph Jackson (J.J.) Lister, who figured out a reliable way to manufacture low distortion microscopes, was a British wine merchant. These two hobbyists made immense and lasting contributions.

It’s hard to imagine how Leeuwenhoek must have felt when he first discovered creatures too small to be seen with the unaided eye. And it’s no wonder that he saw no link between microorganisms and disease: he also found “animalcules” in the mouths and excrement of healthy people.

Leeuwenhoek made his own single-lens microscopes. These were not mere magnifying glasses, though. They consisted of small, hand-polished lenses that could magnify objects up to 270 times mounted between two metal plates.

Many natural philosophers doubted Leeuwenhoek’s credibility; after all, he was untrained and didn’t know Latin. But time after time, Leeuwenhoek’s discoveries were verified by others. He even demonstrated some of his discoveries to Russian Tsar Peter the Great, who was touring Europe incognito.


Leeuwenhoek’s simple microscopes were difficult to use; most natural philosophers preferred compound microscopes. Unfortunately, the instruments suffered from spherical and chromatic aberration. Good microscope makers found they could reduce distortion by using combinations of offsetting lenses. However, producing good instruments was still a trial and error affair.


J.J. Lister is one of the most underappreciated figures in the history of science. (He's best known as the father of Joseph Lister, who introduced antiseptics to surgery and wound care.) In 1829, he discovered the law of aplanatic foci. Now there was a reliable method for producing relatively low distortion microscopes. The floodgates opened to further discoveries. The cell nucleus was first described in detail in 1831. By the 1850s, the germ theory of disease was widely accepted.

Others, such as Ernst Abbe, made important contributions to optical microscope technology. By the early 20th century, microscopes were bumping up against a performance ceiling: the wavelength of visible light. Ernst Ruska won the 1986 Nobel Prize in Physics for developing the first electron microscope, a device that used electromagnetic coils as virtual lenses. Electron microscopes can magnify objects up to one million times. In 1981, a type of electron microscope was employed to produce the first image of an individual atom.

The latest advances include confocal laser scanning microscopes, vitrification of specimens for electron microscopes, and magnetic resonance force microscopes. Confocal microscopes can produce three dimensional images of live specimens. Electron microscopes and magnetic resonance force microscopes are enabling scientists to observe the structure of complex organic molecules.

I suspect we will eventually be able to directly observe most of life’s underlying chemical machinery--both its structure and processes. That portends a future that is at once wonderful and frightening. We will be better equipped to prevent and cure genetic diseases. But we will also learn how to produce custom genomes.


Next time: Medicine's First Power Users


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