Short History of the Microscope
Humans are curious creatures, so it is no surprise that, throughout time, people have yearned to see things that are far smaller than could be seen with the naked eye. This curiosity led to the invention of the microscope: an instrument that enables the human eye, by means of a lens or combination of lenses, to see enlarged images of tiny objects. The following is a brief history of one of the most useful scientific instruments of all time: the microscope.
Although the very first use of a lens is still a mystery, it has been well over 2000 years since humans realised that glass bends light. By the 1st century AD, glass could be produced, and the Romans had begun experimenting with different shapes of clear glass. Through the experiments, they discovered that by holing a piece of glass that was thick in the middle with thin edges, an object below it would look larger.
These early lenses were called magnifiers or ‘burning glasses’. The lenses weren’t used much until the end of the 13th century, when spectacle-makers began producing them to be worn as glasses. Then, around 1600, it was discovered that a variety of optical instruments could be made using a combination of lenses.
The First Microscopes
The earliest ‘microscope’ was really only a magnifying glass since it only had one power, usually about 6X to 10X. It was sometime in the late 1500s, however, that this magnifying glass was improved upon by two Dutch spectacle makers, Zaccharias and Hans Janssen. They put several lenses in a tube and discovered that the object at the end of the tube appeared to be greatly enlarged, with a magnification much higher than that of the magnifying glass.
It was Antony Van Leeuwenhoek (1632-1723), a Dutch draper and scientist, who pioneered microscopy as we know it and, in the late 17th century, became the first man to make and use a real microscope.
With his improved microscope, Leeuwenhoek was able to see things that no one ever had before because of the impossible small particle size: bacteria, yeast, blood cells and tiny animals swimming in a droplet of water.
Naturally, humans wanted to take this amazing discovery and make it even better by increasing the power of the single-lens microscope. People began working on a microscope that incorporated more than one lens so that the image magnified by one lens could be further magnified by the other. Thus, the compound microscope was born.
Englishman Robert Hooke has been officially credited with the discovery of the basic unit of all life: the cell. In the mid 17th century, Hooke discovered a structural mesh when he studied a sample of cork under the compound microscope. He was also the first to use the basic three-lens configuration that is still used in microscopes today.
Modern Day Microscopes
In recent times, the development of the microscope has slowed except for general enhancements and improvements. Optical principles are now well understood and, to an extent, the optical limits have been reached, and the majority of light microscopes used to this day follow the same structural and optical principles that were discovered years ago.