WORLD LEADERS

Biography of Antony van Leeuwenhoek, discoverer of microbes and the first to describe spermatozoa.

Antony van Leeuwenhoek (proununced Layu-wen-hook) was born on October 24, 1632 in Delft, Holland. Leeuwenhoek received only an elementary education and spoke only Dutch, but made some of the most important discoveries in biological history. In 1648, he served as an apprentice in a linen-draper shop. In 1654, he started a business as a fabric merchant. He also worked as a wine assayer, city official and surveyor.

After reading the book, Micrographia, he became interested in microscopes. Compound microscopes which use more than one lens were invented around 1595. Two of the most notable inventors of compound microscopes were Robert Hooke and Jan Swammerdam. Leeuwenhoek did not use the compound microscope to make his observations. He grinded small lenses of short focal length and obtained a resolving power that was greater than that of the early compound microscopes. He learned how to grind lenses and began making observations of various specimens. He made over 500 microscopes. Less than ten have survived. One of his lenses that survives has a magnifying power of about 270 times. Some of his other lenses were even more powerful. The three to four-inch long microscopes were simple devices, which had one lens mounted in a small hole in a brass plate. The specimen were mounted on a sharp point that stuck up in front of the lens. The focus and position could be adjusted by turning two screws.

Leeuwenhoek was very patient and a careful observer. He had a very sharp eyesight. He examined materials such as rain water, small insects, muscle fibers, skin tissues, and many other specimens. He made drawings and notes of his observations. In 1674, he made the first observations of microbes, becoming one of the greatest seminal discoveries in history. He described many types of bacteria and protozoa and calculated their sizes. In 1677, he became the first person to describe spermatozoa and was one of the earliest to describe red blood corpuscles.