Microscope in the 17th and early 20th century
A microscopeis an optical device that allows you to see objects that are invisible to the ordinary eye.
In 1659, the Dutch physicist Huygens designed the perfect eyepiece that was applied to the microscope by the English physicist Hooke (1665). In 1750, Martin designed an achromatic lens, but not quite perfect. The first perfect achromatic lens was built by Fraunhofer in 1811. This lens was then improved by the Italian astronomer Amici (1816-30).
Amici also pointed out a very simple way to eliminate aberration in a large aperture lens. In 1840, for the purpose of further improving the device’s lens, Amici proposed immersion systems in which the volume between the cover glass and the lens was filled with some kind of liquid instead of air.
But now there is a unique one that can be used in different areas of life.
French optician Gartnak realized this idea Amichi, building the first immersion lens (1855).Further improvements were made by Carl Zeiss (in Jena), which began producing microscopes in 1872. This firm owes its success mainly to Professor Aboe, who gave the fundamental theory of the microscope (1874). In addition, Abbe owns the most advanced designs of microscope parts, of which one can, first of all, call the most perfect lens of the microscope — the apochromat.
Based on his theory of microscopic images, Abbe determined the resolution limit of an optical instrument. Helmholtz came to similar conclusions (1874). Abbe's theory was based entirely on the laws of wave optics.
The lens of the microscope received its completion in the so-called monochromat. The use of ultraviolet rays, as follows from the theory of Abbe, made it possible to significantly move the limit of resolution of the microscope. For the first time such devices were designed by Keller and Rohr, working in the company of K. Zeiss.
Well-known bacteriologist R. Koch began to produce systematic photographing through a microscope, which marked the beginning of micrographs.The next step in using the microscope magnification was done in 19-11 by Siedentopf and Zhigmond at the K. Zeiss factory (in Jena). They carried out the so-called ultramicroscope, in which objects were examined by the method of darkened field.
Foucault (1858) and Toepler (1864) applied the method in a slightly different form when studying optical systems and small disturbances in transparent media. With the help of an ultramicroscope, it became possible to view parts hundreds of times smaller than in a conventional microscope. However, their form can no longer be considered.
Thus, the development of the microscope was basically completed by the beginning of the 20th century. Further improvements were no longer of a fundamental nature, but boiled down to purely practical improvements: the improvement of the mechanical system, the improvement of the lighting device, the development of microphotography, micro-kinematography, etc.
Then an electron microscope appeared, in which electron beams are used to form the image. He has already allowed to go beyond the limits that are inherent in a conventional microscope.
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