Microscope History
Explains the development of the microscope, through the centuries. The #1 online retailer for microscopes and microscope accessories. AmScope sells microscopes for everyone at the lowest prices, from students to industry.
Invention of Glass Lenses Long before, in the hazy unrecorded past, someone picked up a piece of transparent crystal thicker in the middle than at the edges, looked through it, and discovered that it made things look larger. Someone also found that such a crystal would focus the sun's rays and set fire to a piece of parchment or cloth. Magnifiers and 'burning glasses' or 'magnifying glasses' are mentioned in the writings of Seneca and Pliny the Elder, Roman philosophers during the first century A. D., but apparently they were not used much until the invention of, toward the end of the 13th century. They were named lenses because they are shaped like the seeds of a lentil.
The earliest simple microscope was merely a tube with a plate for the object at one end and, at the other, a lens which gave a magnification less than ten diameters -- ten times the actual size. These excited general wonder when used to view fleas or tiny creeping things and so were dubbed 'flea glasses.' Anton van Leeuwenhoek (1632-1723) The father of microscopy, of Holland, started as an apprentice in a dry goods store where magnifying glasses were used to count the threads in cloth.
He taught himself new methods for grinding and polishing tiny lenses of great curvature which gave magnifications up to 270 diameters, the finest known at that time. These led to the building of his microscopes and the biological discoveries for which he is famous. He was the first to see and describe bacteria, yeast plants, the teeming life in a drop of water, and the circulation of blood corpuscles in capillaries. During a long life he used his lenses to make pioneer studies on an extraordinary variety of things, both living and non living, and reported his findings in over a hundred letters to the Royal Society of England and the French Academy.
Robert Hooke, the English father of microscopy, re-confirmed Anton van Leeuwenhoek's discoveries of the existence of tiny living organisms in a drop of water. Hooke made a copy of Leeuwenhoek's light microscope and then improved upon his design. Spencer Later, few major improvements were made until the middle of the 19th century.
Then several European countries began to manufacture fine optical equipment but none finer than the marvelous instruments built by the American, Charles A. Spencer, and the industry he founded. Present day instruments, changed but little, give magnifications up to 1250 diameters with ordinary light and up to 5000 with blue light. Beyond the Light Microscope A light microscope, even one with perfect lenses and perfect illumination, simply cannot be used to distinguish objects that are smaller than half the wavelength of light.
White light has an average wavelength of 0.55 micrometers, half of which is 0.275 micrometers. (One micrometer is a thousandth of a millimeter, and there are about 25,000 micrometers to an inch. Micrometers are also called microns.) Any two lines that are closer together than 0.275 micrometers will be seen as a single line, and any object with a diameter smaller than 0.275 micrometers will be invisible or, at best, show up as a blur. To see tiny particles under a microscope, scientists must bypass light altogether and use a different sort of 'illumination,' one with a shorter wavelength.
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Examine a 200 year old flea and sample of mouse hair using a selection of microscopes.. 'For what a better, fitter, gift Could be in this world's Aged Luciosity? To help our Blindness so as to devize a pair of new & Artificial eyes.' Henry Power, In Commendation of ye Microscope, 1661 Earliest history The 17th century saw the microscope put to its first serious use; a number of natural philosophers set about exploring the microscopic world. Henry Power's poem captures the optimism about its potential.
After the 1665 publication of Robert Hooke's book Micrographia, and the work of natural philosophers on the continent, the only problem that seemed to stand in the way of the further use of the microscope was the fear that it had shown all that it was possible to see of the microscopic world. From this early period the Whipple Museum has two microscopes, one of them English, the other Italian (Image 1). The 18th century In the 1740s a number of books were published that seemed to give the microscope new direction. Before this there was a perceived decline in the use of the instrument. 'Perceived', both then and now, because the relatively high production and use of the microscope did not match the relatively low number of important discoveries. Two optical problems stood in the way of further development: spherical and chromatic aberration. Rather than concentrate on these problems, the articles here covering the 18th century deal with the ways in which the microscope was manufactured and sold; the way in which it was used in public demonstrations; and the various ways in which the instrument's design was altered to meet the needs of its users.
The work of 'natural philosophers', many of whom were fascinated with the microscopic world, provides enormous amounts of historical material, and allows us to try to understand the 18th century on its own terms. ยป The 19th century Again, the 19th century saw technical developments that are well represented at the Whipple Museum. Earlier design alterations had made microscope manipulation easier, but now optical improvements that increased the magnification and resolving power of microscopes led to many discoveries. Moreover, the problems of spherical and chromatic aberration were solved before 1830. With the specialisation of science into different disciplines, the microscope found a number of different homes.
Biology, palaeontology (the stody of fossils), medicine, geology, and host of other subjects all included the use of the microscope, though usually through the work of only a handful of 'microscopists'. Aside from one of the first achromatically and spherically corrected microscopes ever made, the Whipple has several microscopes with interesting associations: Charles Darwin's large compound microscope, Giovanni Battista Amici's reflecting microscope, and some pieces associated with John Stevens Henslow are the highlights here. In each case we can take the microscope and its history as a way of understanding the scientists who used it, allowing us to see them at work, and engaged in the practice of science. The 20th century Of all the periods in the history of the microscope this is the least researched. There is certainly a huge amount of material that is not yet properly understood, either in terms of its importance or its place in the history of modern science (Image 2). The museum has a number of recent microscopes, one of which is included in.