The devices we call microscopes have been around for hundreds of years. Although microscopes as we know them were not invented for the first time until the 1500s, even ancient people explored the uses of lenses to make objects look larger. However, much controversy revolves around who was the first to invent the microscope. In any case, microscopes have played a critical role in both science and medicine, used to discern objects invisible to the naked eye like one-celled organisms and bacteria. The invention of light microscopes has also led to other forms of microscopes. Microscopes have changed the way we see the world.
Before the sixteenth century, it was known that lenses could be used to make objects appear larger. In the thirteenth century, an Italian named Salvino D’Armate made an eye glass using a lens that magnified objects. These first magnifiers were called flea glasses because scientists could use them for observing small insects like fleas. These early forms of magnifiers were not extremely powerful; they magnified at about six to ten times. However, they formed the foundation of the development of light microscopes. They made it possible for us to have the microscopes that we enjoy today.
The discovery of the principles that allow microscopes to function can be credited to the Netherlands in the 1590s. A father and his son, Hans and Zacharias Janssen experimented with several lenses and discovered that when they put several lenses in a tube, the objects seen through the invention were much larger than just using one lens. Their early version of the microscope was not that beneficial to science but it did provoke other optic inventions. Galileo, the famed astronomer, took their design and improved upon to create one of the first telescopes. Janssen and his son took their discovery and invented a primitive version of what we call a compound microscope, devices that magnify objects in two stages.
Anton van Leeuwenhoek
However, it was a man by the name of Anton van Leeuwenhoek from the Netherlands who is called the father of microscopy because he was the first to make use of a modern microscope. Van Leeuwenhoek worked with lenses to produce those that could magnify up to over 270 times and used these microscopes to make some incredible discoveries that would have significance for both science and medicine. Van Leeuwenhoek was the first to observe and be able to describe microorganisms like bacteria and protozoa in a drop of water. He also observed yeast plants and discovered the small eggs of insects. As far as physiology, van Leeuwenhoek also was the first to observe the circulation of blood through the body’s capillaries.
Other people after van Leeuwenhoek expanded on his work. An Italian named Marcello Malpighi was a doctor who used microscopes to observe human organs and supported the theory that arteries in the body distribute blood from the lungs to other parts of the body. He also observed taste buds and the corpuscles in the blood that make it red. Robert Hooke, an Englishman, also expanded on van Leeuwenhoek’s work. His most famous work is <i>Micrographia</i> published in 1665. The book is an accumulation of what Hooke observed using a microscope and includes hand drawn illustrations. He observed a variety of objects, including fleas, snow, and corks. When he was observing corks, he saw pores and decided to call them cells. Little did he know that this term would have an enormous impact on science. The term cell would be forever used to describe the basic structural units of all living things.
20th Century Microscopes
Microscopes did not change much during the next two to three hundred years, although the magnification capability of microscopes grew larger and larger. On the other hand, the twentieth century saw the development of the first electron microscopes because light microscopes cannot be used to see objects smaller than the wavelength of light. Scientists wanted to use a different medium with a shorter wavelength. In the 1930s, Germans Max Knoll and Ernst Ruska developed the first electron microscope and won a Nobel Prize for their efforts. Electron microscopes are inherently more powerful because they make it possible to view objects as small as the diameter of an atom. Electron microscopes can magnify objects up to one million times.
One the other hand, electron microscopes have a serious disadvantage. Since they magnify objects in a vacuum, living cells cannot survive under these conditions. This has led to a renewal of sorts of light microscopes, which are favored by biologists who can see cells in action. To overcome the disadvantages of light microscopes, they are now used in conjunction with computers, polarized light, and video cameras among other things. Microscopes are still indispensable for observing the life that is too small to see with the naked eye.
Benefits Of Microscopes
Overall, the invention of the microscope has led to several profound discoveries within science and medicine including how the body works and the life of one-celled organisms. Microscopes have aided in the discovery of cells, the building blocks of life, and helped scientists explain how diseases affect the body. Many different men have contributed to the invention of the microscope including Hans and Zacharias Janssen, Anton van Leeuwenhoek, and Robert Hooke. The microscope, whether it is light or electron, continues to help us explore more of our world.