By the end of the nineteenth century microbiology developed as a new branch of science, with important prospects for implementation in medicine and the fermentation industry. Antonie van Leeuwenhoek, who lived in Delft, had been the first one to see bacteria, by using his own-made lenses. His accurate observations were published in 1674 in Letters to the Royal Society in London. Two centuries later, also in Delft, the production of bakers yeast on an industrial scale was started by the "Gist- en Spiritusfabriek". This company has since then developed into the Royal Gist-Brocades company (now part of DSM). An employee of this factory was microbiologist Martinus Willem Beijerinck, whom in 1895 was appointed as the new Chair in Microbiology at the Polytechnic in Delft (later converted into the Delft University of Technology). Beijerinck therefore became the first Professor in General Microbiology in The Netherlands. Some 10 years earlier the University of Amsterdam had already installed a Chair in Medical Microbiology and one of the alumni was Christiaan Eijkman, who later became Professor in Medical Microbiology at the University of Utrecht. Due to an increased interest for the research on micro-organisms the Netherlands Society for Microbiology was established on April 20, 1911, with Beijerinck as the first chairman.