In 1610, the Italian astronomer Galileo turned the telescope toward the skies and opened up a new universe to exploration.
Antonie van Leeuwenhoek did the same with his microscope and a different universe.
In a long life of careful observation and recording, he made many discoveries.
Leeuwenhoek studied his own blood and discovered red and white corpuscles.
He studied the blood vessels of animals and discovered the tiny capillaries, from the Latin for “hair-like”, that carry blood from the arteries to the veins.
Fifty years before, the great English anatomist William Harvey had discovered that blood flows away from the heart in arteries and back to the heart in veins, but he could not see how blood flowed between them.
The capillaries Leewenhoek discovered were that missing link.
Leeuwenhoek studied skin, hair, dust, and insects. In plants, he revealed the complex structure of roots, stems, and leaves.
Whatever he saw, he verified with many observations and he described in tremendous detail. He hired an illustrator to prepare accurate drawings of his findings.
The people of Delft thought he was a little crazy, but the scientists at the Royal Society in London were fascinated by his work.
Over his lifetime, he sent the Society 375 scientific papers on his findings.