Google celebrates Antonii van Leeuwenhoek

Today is the birthday of Antonii van Leeuwenhoek, and in honor of his achievement Google made an animated Doodle (click on it to go to Google). Since Matthew is an expert on the man and his science, which forms a part of his book The Egg and Sperm Race (also called Generation), I asked him to write a few words about the honoree (below).


by Matthew Cobb

Antonii Leeuwenhoek (he adopted the aristocratic ‘van’ as a pretension later in life) was one of the great figures of 17th century discovery. He was a draper, not a scholar, and yet he was able to make two of the most amazing discoveries in the history of science. Like many other people in the 17th century Dutch republic (including the great philosopher Spinoza), Leeuwenhoek (roughly pronounced Lay-wen-hoak) made microscopes out of a tiny bead of glass.

The lens was then put into a rectangular metal frame, and the object to be looked at (an insect, or a fluid in a capillary tube) was put on a rod on one side of the lens. The Google doodle shows this quite well. He then had to hold the apparatus into the sunlight (candlelight would not do) to see what he could see. Single lens microscopes were much more powerful than the compound microscopes of the time.

Leeuwenhoek’s two great discoveries were made early in his career (he was introduced to the Royal Society by one of his neighbours, the Delft-based Reinier de Graff, in 1672). In 1674, de Graaf was trying to find out why pepper is hot, so he ground up some pepper corns in water and allowed the solution to move up a capillary tube. His idea was to see the structure of whatever it was in pepper that made it spicy. Instead, he observed bazillions of tiny ‘animacules’ – bacteria and protists – zipping about in the water. For some years, it was assumed that the tiny things were released from the peppercorns, and it was called the ‘pepper water’ experiment. Until someone did the obvious thing of leaving out the pepper… Micro-organisms are still called ‘infusoria’ after this principle of making an ‘infusion’.

Leeuwenhoek’s second, and astounding discovery was made in 1677, when following the suggestion of a medical student, called Ham, Leeuwenhoek looked at his semen (this had previously been suggested to him by the Secretary of the Royal Society, Henry Oldenburg, but Leeuwenhoek declined to take the step). The description of how he did the experiment, which eventually appeared *in Latin* (not English) in the Philosophical Transactions of the Royal Society is interesting:

He reassured “his Lordships” that he had not obtained the semen by any “sinful contrivance” but by “the excess which Nature provided me in my conjugal relations.” Think about that. He goes on to say that a mere “six heartbeats” after ejaculation, he found “a vast number of living animalcules” in his ejaculate (it is not recorded what his wife thought of this…). The Royal Society didn’t believe him, and in classic modern style sent him away to do more experiments. Eventually, they published his report in 1678.

Several points: firstly, Leeuwenhoek at first thought that the sperm he saw were simply parasites (and this is reflected in the name we still give them – spermatozoa, the animals that live in semen). Second, he thought the interesting bit of the ejaculate was some weird thready material that no one else has seen before or since. He eventually changed his mind on this. Finally, although it had been suggested 10 years earlier that women have eggs, and de Graaf had shown experimental support for this idea in 1672 in rabbits, the scientific world did not recognise that egg and sperm were complementary components of the future organism.

That did not happen until the 1840s, after a) it was realised that something was inherited (the word ‘heredity’ had no biological meaning before the 1820s) and b) it was realised that all organisms are composed of cells, and therefore that egg and sperm were both cells. Instead, for 140 years science was more or less divided into the ovists and the spermists. For the spermists, like Leeuwenhoek, the egg was either non-existent (as in mammals) or food for the sperm; for the ovists (most people) the sperm somehow ‘awoke’ the egg, like an electric shock, but played no equal role in producing offspring.

Leeuwenhoek was an extraordinary man who made remarkable contributions to our understanding of the world. If you want to know more about him, and the weird route ideas took to come to our current understanding, despite it looking so obvious in retrospect, you can pick up a good second-hand copy of my 2006 book Generation, for less than $4! (In the UK it was called The Egg and Sperm Race…)



  1. GBJames
    Posted October 24, 2016 at 8:52 am | Permalink

    I read Generation and very much enjoyed it!

    • rickflick
      Posted October 24, 2016 at 9:59 am | Permalink

      Me too.

  2. Historian
    Posted October 24, 2016 at 8:58 am | Permalink

    Matthew, thanks for this fascinating post. I had no idea that it wasn’t until the 1840s that it was realized that “egg and sperm were complementary components of the future organism.”

    • Posted October 24, 2016 at 9:34 am | Permalink

      Ditto, thanks, Matthew,

    • Posted October 24, 2016 at 12:03 pm | Permalink

      Matthew is correct, but there’s a bit more complication, because there were competing embryologies (for lack of a better phrase) for a long time which thought there was definitely a female contribution. In fact, some held that the menstrual blood was one (expelled when not used, etc.) and others thought that female genital lubricant (!) was involved somehow.

  3. dabertini
    Posted October 24, 2016 at 9:18 am | Permalink

    In 1976 my parents bought me a microscope for xmas, which I asked for. For my birthday, the following year, they bought me prepared slides. I still have both. I consider them priceless “toys”. I also have a copy of the how and why wonder book of the microscope of the same vintage. Great memories.

  4. ThyroidPlanet
    Posted October 24, 2016 at 9:21 am | Permalink

    Holy animalcules, this was a good post!

    BTW the name of that website MC took down – not the best of titles. Maybe a different title would help?

  5. Ken Kukec
    Posted October 24, 2016 at 9:21 am | Permalink

    … (he adopted the aristocratic ‘van’ as a pretension later in life) …

    Hell, if he wanted to go full aristo, he should’ve sprung for a first initial and Roman numeral to follow.

    Interesting piece, MC.

  6. crozer1
    Posted October 24, 2016 at 9:26 am | Permalink

    Fascinating post Matthew!

    For the interested reader, here’s a link to some instructions for making your own Leeuwenhoek microscope. I haven’t tried this myself but would like to.

  7. Hempenstein
    Posted October 24, 2016 at 10:07 am | Permalink

    I still remember in grade school (3rd grade, I think), for science we put some things on the windowsill and watched them decay. One was peppercorns in water. Always wondered why peppercorns. Question answered nearly 60yrs later!

  8. kevin7alexander
    Posted October 24, 2016 at 10:26 am | Permalink

    It’s very significant that he was a draper. The single lens microscope that he used was a tool of the trade, used to examine the quality of the threads that made the cloth he traded in. He was familiar with the tool but may have been the first to put it to other use or at least the first to write about it.

    • Ken Kukec
      Posted October 24, 2016 at 10:43 am | Permalink

      When you guys say he was a “draper,” you mean he actually made drapes? I thought maybe “draper” was pommie slang, like “punter” or “tosser”.🙂

      • Heather Hastie
        Posted October 24, 2016 at 11:20 am | Permalink

        No. What you call drapes are called curtains by many of us. A draper was a retailer or wholesaler if cloth of all descriptions, though some specialized in particular types of cloth. England, for example, had been known as a manufacturer of high quality woolen cloth for centuries and those that sold it were among her wealthiest citizens.

        • Ken Kukec
          Posted October 24, 2016 at 12:19 pm | Permalink

          Thanks for the heads-up, Heather.

          Though I can’t say I’ve ever been one to care if the carpet matches the curtains …

          • infiniteimprobabilit
            Posted October 24, 2016 at 6:51 pm | Permalink

            I can think of all kinds of interpretation of that phrase. At least one of them unexceptionable.


        • Gregory Kusnick
          Posted October 24, 2016 at 1:04 pm | Permalink

          In the theater and fashion world, a draper is someone who constructs costumes and fits them to performers or models, i.e. a high-end tailor.

          • Ken Kukec
            Posted October 24, 2016 at 2:20 pm | Permalink

            Oh, like Edith Head. Now I see.

            • Gregory Kusnick
              Posted October 24, 2016 at 2:40 pm | Permalink

              If we’re nitpicking, Head is known primarily as a designer. A draper translates designs on paper into actual costumes on people, just as stonemasons and other artisans translate architectural drawings into buildings. Of course a draper may sometimes do design work as well, but they’re usually considered different specialties.

              Not that I’m claiming that Leeuwenhoek was a draper in this sense; he appears to have been in the retail fabric business. But the two senses of “draper” are not unrelated; full-service fabric shops might well have had tailors (drapers of the second sort) on staff to create clothing from the chosen fabrics.

              • Ken Kukec
                Posted October 24, 2016 at 5:03 pm | Permalink

                Oh, I got fitted by one of those guys once. Asked me if I “dressed to the right or to the left?” (Gotta admit, I hadn’t the foggiest.)

    • Mark Sturtevant
      Posted October 24, 2016 at 12:52 pm | Permalink

      As I understand it, he knew how to make the lenses and his were the best for some time. He made many of these little microscopes, and gave many of them away. I did not know that the tool was otherwise familiar to those in the drapery profession.

    • Posted October 24, 2016 at 4:25 pm | Permalink

      While this is a widely- held view, there is no evidence for it that I am aware of. Can you point me to a contemporary source, Kevin?

  9. Posted October 24, 2016 at 12:04 pm | Permalink

    Does anyone know if there are any good collected works of L. in English?

  10. Posted October 24, 2016 at 12:18 pm | Permalink

    I was severely infected by Giardia lamblia thirty years ago while in the Caucasus Mountains. Remembering that Giardia was one of the first pathogenic microorganisms observed by Leeuwenhoek, strangely relieved my agony, though only for a few seconds.

  11. P. Puk
    Posted October 24, 2016 at 12:45 pm | Permalink

    Leeuwenhoek (roughly pronounced Lay-wen-hoak)

    Lieu-wen-hook is a little less rough pronunciation. A Dutch speaker might wince at the former but they would certainly recognise the latter.

    • Posted October 24, 2016 at 8:54 pm | Permalink

      Would not the “w” be pronounced as a “v”?

      • p.puk
        Posted October 25, 2016 at 3:39 am | Permalink

        It might depend on the accent and I’m not at all sure how his contemporaries would have pronounced it.

        But it’s definitely not a hard V. On its own, “Leeuw” is pronounced more like “lay-ooh” as a single syllable – hence my use of “lieu” above. There is no hint of a “V”.

        When combined into the full name the “W” might sound somewhat like an English “V” as the Dutch “V” sounds more like an English “F”.

        It took a full 18 months to tune my ear to that language. Leeuwenhoek is rather high on the difficulty scale for an English speaker. Next up, you’ll need to master “Scheveningse scholletjes.”

        Lagniappe: “Hottentottenlegertentententoonstellingopleidingsprogramma” is a legitamate – although nonsense – Dutch word.

        Stringing nouns together is a feature of Dutch/German and this one is about a “training programme for the exhibition of Hottentot army tents.”

        You’re welcome.

  12. Gregory Kusnick
    Posted October 24, 2016 at 12:50 pm | Permalink

    In 1674, de Graaf was trying to find out why pepper is hot, so he ground up some pepper corns in water and allowed the solution to move up a capillary tube.

    This seems to say that the discovery was made by de Graaf. I presume “he” is meant to refer to Leeuwenhoek.

    • Posted October 24, 2016 at 4:26 pm | Permalink

      Oops.,thats what comes of writing a post quickly when PCC commands it and you have to dash to work!

  13. Mark Sturtevant
    Posted October 24, 2016 at 12:54 pm | Permalink

    One of my treasured books from my childhood is The Microbe Hunters, which is a series of short biographies about Leewenhoek, Koch, Pasteur, etc. I do not remember the racy bit about how he got the sperm, thought.

  14. Tom
    Posted October 24, 2016 at 1:50 pm | Permalink

    “Antonii” should be “Antonie”. “Antonii” looks like the genitive of the latinized “Antonius”.

  15. infiniteimprobabilit
    Posted October 24, 2016 at 6:57 pm | Permalink

    ‘He reassured “his Lordships” that he had not obtained the semen by any “sinful contrivance” but by “the excess which Nature provided me in my conjugal relations.”’

    There may have been a scientific (as opposed to ‘moral’) point to that. At the then state of knowledge it may have been quite possible that the nature of the product obtained was influenced by the method of obtaining it.


  16. kps
    Posted October 24, 2016 at 8:29 pm | Permalink

    Doodle permalink, for those reading from the wrong day and/or country:

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