Scientist. He was known as the "Father of Modern Microbiology". Born in Delft, Holland, he received only an elementary education and spoke only Dutch, but made some of the most important discoveries in biological history. After serving as an apprentice in a linen-draper shop, in 1654, he started a business as a fabric merchant while also working as a wine assayer, city official and surveyor. After reading the book "Micrographia," he became interested in microscopes or compound microscopes. He did not use the compound microscope, which use more than one lens and were invented around 1595, 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 began making observations of various specimens while making over 500 microscopes with less than ten surviving. The three to four-inch long microscopes were simple devices, which had one lens mounted in a small hole in a brass plate. The specimens 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. With his 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. He wrote letters to the Royal Society of London, the leading scientific society during that time, and corresponded with them for fifty years, detailing his observations with his microscopes. The letters were translated into English and Latin and published in the "Philosophical Transactions of the Royal Society". In 1680, he was elected a fellow of the Royal Society of England and was also a corresponding member of the Academy of Sciences in Paris. In a letter written to the Royal Society, the pastor of the New Church at Delft wrote about Leeuwenhoek, "For which reason, by diligence and tireless labour he made with his own hand certain most excellent lenses, with the aid of which he discovered many secrets of Nature, now famous throughout the whole philosophical World".

(bio by Richard Kaplan)