Portrait of Antoni van Leeuwenhoek taken from his book Arcana Naturae detecta (1695). A Dutch microscopist, he was born in Delft, Netherlands, on October 14th 1632 & died on August 26th 1723. Leeuwenhoek built his own microscopes, grinding the lenses himself, according to a single-lens design that could magnify up to nearly 200 times. He was not the first microscopist, but his instruments enabled him to see further into the magnified world than any of his predecessors. His passion for observation & his discoveries revolutionised the science of biology. He was the first to observe & describe bacteria, protozoa, & sperm. Reference: MICROCOSMOS, page 186.