On March 3, 1931, German physicist Ernst Ruska together with his doctoral advisor Max Knoll presented the very first prototype electron microscope, capable of four-hundred-power magnification; the apparatus was the first demonstration of the principles of electron microscopy.
On October 24, 1632, the Dutch tradesman and scientist Antonie van Leeuwenhoek, the inventor of the microscope, was born. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist.