The man who discovered a new world in a drop of water

Science for Kids

This is a true story about a man who lived in the Netherlands more than 300 years ago.

Antoni van Leeuwenhoek was born in 1632, and lived in a city called Delft. He was married and had one child, a girl called Maria. He was quite a well-known person around town and he made a living selling woollen cloth and other fabric.

Antonius van Leeuwenhoek. Coloured stipple engraving by J. Chapman, 1813, after J. Verkolje. [CC BY 4.0 (], via Wikimedia Commons
Antonius van Leeuwenhoek. Coloured stipple engraving by J. Chapman, 1813, after J. Verkolje. [CC BY 4.0 (], via Wikimedia Commons

Cloth sellers liked to look at their cloth up close with a magnifying glass. A magnifying glass is a lens, which is piece of glass in a special shape that can make things look bigger than they are.

Antoni taught himself how to make much better lenses. He made these into microscopes. These could make things look at least 200 times bigger than they really are! These microscopes don’t look anything like the big microscopes we have today. They were quite small and you had to hold them up very close to the eye.

Using these home-made microscopes Antoni could see things that were smaller than anyone had ever seen before.

Antoni was curious, and he loved to explore things with his microscopes. So he explored a lot of the things that he found around him. When he looked in a drop of water he saw tiny living things that people had never imagined before. He called them “animalcules”.

Antoni wrote about these tiny creatures to a club for important scientists called the Royal Society. These scientists thought well of him as a scientist until they read his letter about a tiny world inside a drop of water. They laughed and thought he was being silly. But when they saw these creatures for themselves they were convinced and soon made him a member of their club.

Many people were amazed, and kings and queens wanted him to show them these little creatures. Today we call these tiny creatures Protists.

Antoni didn’t work as a scientist, but in fact he was doing real science with his home-made microscopes. He made a lot of very important discoveries.


For the grown-ups

Google has marked Antoni van Leeuwenhoek’s 384th birthday. Who was he? He wasn’t a scientist, but he was. He wasn’t a professional scientist, but he was a true, groundbreaking scientist. He’s been praised* for having an open mind: he knew the difference between fact and speculation, and he wasn’t held back by incorrect beliefs of the time, such as scientists often find it hard to break away from. As he himself said, his discoveries were driven by his exceptional curiosity.

He discovered bacteria, protists, sperm, microscopic nematode worms, the crystals that cause gout, and much more. He worked out that fly eyes are made of many small eyes. This idea was also ridiculed by scientists of the day.

Children are naturally curious. I hope the story of Van Leeuwenhoek will inspire young children to treasure and nurture their curiosity.


A replica of a van Leeuwenhoek microscope

Check this page for a photo of one of the microscopes being used properly – held right up to the eye.

Includes extracts from letters to and from the Royal Society. The members said they giggled at van Leeuwenhoek’s description of animalcules.

How the lenses and microscopes were made

About van Leeuwenhoek as a scientist, and his own descriptions of some of his discoveries:

* Reference to Dobell’s quote in Antonj van Leeuwenhoek “Father of Microbiology” by Dobell C. (ed.) 1992, 1960. Antony van Leeuwenhoel and His Little Animals. Dover Publications, New York