Science Matters – animalcules magic

Want to read more?

We value our content, so access to our full site is  only available on subscription.

Your subscription entitles you to 7-day-a-week access to our website, plus a full digital copy of that week’s paper to read on your pc/mac or mobile device.

And there’s more – your subscription includes access to digital archive copies from 2006 onwards

Already a subscriber?


Subscribe Now

[Usual Science Matters logo at head of story]

Recently I ate a very peppery bacon sandwich. Delicious, and it got me thinking about a legendary figure in the history of microbiology.

In the 1670s a Dutchman from Delft called Antoni van Leeuwenhoek made the first ever microscope.

He was a draper by trade, and used magnifying lenses to count the thread density of cloth as a judge of its quality. This led him to grind his own lenses and soon he was using these – and the microscope that followed – to magnify anything that interested him.

Among the first things he looked at was pepper to see how it produced its spicy taste – he thought perhaps it might contain scratchy prickles or spikes. He soaked the pepper in water for three weeks and then peered at it under his lens, but he couldn’t solve the mystery of the spicy taste (which, we now know, is caused by the chemical capsaicin). Nevertheless, he did see some tiny creatures, which he called ‘animalcules’ – now known as bacteria – moving about in the water under his lens.

This was the first-ever glimpse of the world of microbes.

Excited, Leeuwenhoek took to examining all manner of things, including ‘scurf from a man’s teeth’. In a letter to the Royal Society in London he declared the number of these tiny creatures in this material to be ‘so many that I believe they exceed the number of Men in a kingdom’.

He went on: ‘For upon the examination of a small parcel of it, no thicker than a horse-hair, I found too many living animals therein, that I guess there might have been 1000 in a quantity of matter no bigger than a 1/100th part of a [grain of] sand.’

Fellows of the Royal Society were sceptical, but were eventually convinced when others, including the famous scientist of the day, Robert Hooke, repeated the observation. Meanwhile Leeuwenhoek went on to describe spermatozoa, muscle fibres and blood cells flowing in capillaries.

A truly amazing self-taught man, now known as ‘the father of microbiology’.

But I wonder how many animalcules were lurking in my bacon sandwich?


The father of microbiology – Antoni van Leeuwenhoek. no_a12ScienceMatters01