Antonie van Leeuwenhoek

Born on 24 October 1632 in Delft, the Netherlands, Antonie van Leeuwenhoek was a scientist whose skill with microscope optics led to the establishment of microbiology. He had little formal schooling and became an apprentice to a linen draper at age 16. During his apprenticeship van Leeuwenhoek saw his first basic microscope, essentially a magnifying glass fastened to a stand. After attaining a secure government job, he increasingly pursued his hobby of grinding lenses to build his own microscopes. Rather than making complicated compound microscopes with multiple lenses, van Leeuwenhoek would mount one small, intricately crafted short-focal-length lens in a hole within a brass plate. Using his homemade microscopes, he became the first person to observe single-celled organisms , which he called animalcules. Around 1674 he observed protozoa, followed a few years later by bacteria. He studied sperm cells, insects, and red blood cells. Some of van Leeuwenhoek’s lenses were found to have magnification between 50x and 300x, an impressive achievement for his time. Scientists still aren’t sure what combination of lighting and other tricks he used to attain such detailed observations. He died in 1723 at age 90. (Portrait by Jan Verkolje)

Date in History: 24 October 1632