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Invention of Telescope or Microscope
Zacharias Janssen invented the telescope and/or the microscope in Middelburg between 1590 and 1618. Zacharias worked for some period of his life as spectacle-maker (a very competitive and secretive trade) and at one time lived next door to Middelburg spectacle maker Hans Lippershey, also claimed to have invented the telescope. -
Jan Baptist van Helmont
Flemish physician, philosopher, mystic, and chemist who recognized the existence of discrete gases and identified carbon dioxide -
Anton van Leeuwenhoek
Dutch microscopist who was the first to observe bacteria and protozoa. As a hobby, Leeuwenhoek began grinding lenses and using them to study minute objects, particularly small organisms. His researches on lower animals refuted the doctrine of spontaneous generation, and his observations helped lay the foundations for the sciences of bacteriology and protozoology. -
Lorenz Oken
he German naturalist and nature philosopher was the first of a series of works which established him as a leader of the movement of "Naturphilosophie" in Germany. Birthplace in Ortenau (Bohlsbach, Baden). Old picture postcard from 1880.
In it he extended to physical science the philosophical principles which Immanuel Kant had applied to epistemology and morality. Oken had been preceded in this by Gottlieb Fichte, who, acknowledging that Kant had discovered the materials for a universal science -
Theodor Schwann
German physiologist who served as an assistant to Johannes Müller. He discovered the digestive enzyme Eric Weisstein's World of Chemistry pepsin in 1836. He showed that yeast were tiny plant-like organisms, and suggested that fermentation was a biological process. Schwann was a master microscopist who examined animal tissue, specifically working on notochord development in tadpoles