Father and son Hans and Zacharias Jensen invent the microscope. However, it is still very primitive, as it can only magnify opaque objects, and even then, can only magnify 20X.
Robert Hooke Publishes "Micrographia"
Robery Hooke, the Secretary of the Royal Society, publishes "Micrographia", which is a collection of 38 copper-plate illustrations of objects seen under a microscope.
Leeuwenhoek Coins the Term "Cells"
Antony Van Leeuwenhoek, who was not formally trained with the workings of the microscope, discovers some of the most important elements of microbiology. He discovers bacteria, sperm cells, blood cells, and more.
Leeuwenhoek reports "Little Animals"
Leeuwenhoek reports to the Royal Society of his discovery of "little animals", which are today identified as bacteria and protozoa.
Van Deyl Creates Achromatic Lenses for Microscopes
Harmanus van Deyl begins creating achromatic lenses for microscopes, greatly improving their quality.
Schleiden Discovers that Plants are made of Cells
Matthias Jakob Schleiden discovers that all plants are made of cells. Later, with Theodor Schwann, they propose that all life is made of cells.
Schwann Publishes Findings on Cells
Aided by Matthias Jakob Schleiden, Theodor Schwann publishes his findings, and concludes that all plants and animals are made up of cells.
Virchow's Theory of Cell Reproduction
Rudolf Virchow proposes that cells do not randomly generate, but are created from other cells. His theory is later proven by Louis Pasteur.
Pasteur Disproves Spontaneous Generation
Louis Pasteur proves that cells come from other cells with his famous broth-boiling experiment. This contradicts the common theme of spontaneous generation (life from nowhere) that was believed at the time.
Abbe Publishes his Findings on the Theory of the Microscope
Ernst Abbe publishes his findings on the microscope. Among these things, he defines the differences between resolution and magnification, criticizing those who use overly powerful eye pieces as having "empty magnification".
Ernst Leitz Microscope Patented with Revolving Turret
The Ernst Leitz Microscope is patented, with a revolving head (or "turret") for 5 different objectives of focus, one per lens.
Flemming Discovers Mitosis
On this date, Walther Flemming discovers mitosis, one of the two ways that cells reproduce.
Kohler invents the Microscope Lamp
August Kohler creates the microscope lamp, allowing for artificial light to be used to view samples, as opposed to natural light via mirrors.
Pasteur and Koch begin Studying Microscopic Organisms
Louis Pasteur and Robert Koch begin studying microscopic organisms and bacteria during this time.
First Commercial UV Microscope
This instrument is capable of viewing twice the resolution of visible light microscopes.
Zernike creates the Phase Angle Ray Microscope
Fritz Zernike creates the Phase Angle Ray Microscope, which uses the phase angles of rays to view the subject. It took until 1941 for a commercial model to be created.
First Electron Microscope Invented
The first Electron Microscope is created by Max Knoll and Ernst Ruska.
First Electron Micrograph of a Biological Sample
The first electron micrograph of a biological sample (long-leaved sundew fixed with osmium) is taken.
First Commercially Available Electron Microscope
Siemens begins supplying the first commercially available electron microscope.
First Diamond Knife
The first diamond knife is invented. This tool is capable of slicing pieces of organic material as thin as 500 angstroms (10 to the power of -10 meters).
Scanning Laser Confocal Microscope is commercially available
This device used lasers to view the object in its focus.