MICROSCOPEHISTORYLike many inventions today there are disputes in origins of the original inventors. The same dispute applies to who invented the microscope. Dating back to the first century when glass was first invented, the Roman's were investigating the use of glass and how viewing objects through it, made the objects appear larger. Then, in the 13th Salvino D'Armate from Italy, made the first eye glass, providing the wearer with an element of magnification to one eye. The earliest simple forms of magnification were magnifying glasses, usually about 6x - 10x and were used for inspecting tiny insects such as fleas, hence these early magnifiers called "flea glasses".

The early simple "microscopes" which were only magnifying glasses had one power, usually about 6x - 10x. One thing that was very common and interesting to look at, were fleas and other tiny insects, hence these early magnifiers called "flea glasses".

Sometime, during the 1590's, two Dutch spectacle makers, Zaccharias Janssen and his father Hans started experimenting with these lenses. They put several lenses in a tube and made a very important discovery. The object near the end of the tube appeared to be greatly enlarged, much larger than any simple magnifying glass could achieve by itself!Their first microscopes were more of a novelty than a scientific tool since maximum magnification was only around 9X and the images were somewhat blurry. Although no Jansen microscopes survived, an instrument made for Dutch royalty was described as being composed of "3 sliding tubes, measuring 18 inches long when fully extended, and two inches in diameter". The microscope was said to have a magnification of 3x when fully closed, and 9x when fully extended.It was Antony Van Leeuwenhoek (1632-1723), a Dutch draper and scientist, and one of the pioneers of microscopy who in the late 17th century became the first man to make and use a real microscope.He made his own simple microscopes, which had a single lens and were hand-held. Van Leeuwenhoek achieved greater success than his contemporaries by developing ways to make superior lenses, grinding and polishing a small glass ball into a lens with a magnification of 270x, the finest known at that time (other microscopes of the time were lucky to achieve 50x magnification). He used this lens to make the world's first practical microscope.Leeuwenhoek's microscope used a single convex glass lens attached to a metal holder and was focused using screws. Anthony Leeuwenhoek became more involved in science and with his new improved microscope was able to see things that no man had ever seen before. He saw bacteria, yeast, blood cells and many tiny animals swimming about in a drop of water. People did not realize that magnification might reveal structures that had never been seen before - the idea that all life might be made up of tiny components unseen by the unaided eye was simply not even considered.

CARE Always carry the microscope with two hands. Keep the microscope at least 6 inches from the edge of the lab table, and keep the excess electrical cord on the table top. Do not touch the glass lens with your fingers. Clean the lenses with lens paper only, and wipe the lenses before and after each use. Always remove the oil from the oil-immersion objective with lens paper before putting the microscope away. Do not tamper with any of the components of the microscope. Always be certain that the low-power objective is in place before putting the microscope away. Always unplug the electrical cord by pulling on the plug, not the cord. Never look through the microscope while rapidly reducing the distance between the objective lens and the slide. Always observe this movement from the side of the microscope to prevent damage to the objective lens.

TYPESHow many different types of microscopes are there? More than you probably thought. I tried to research a list of different types, based on the physical principle used to make an image. Of course, one could also classify the microscopes based on their area of application, their cost, their versatility or any other aspect. These classification systems do have a problem: In this case one one type of microscope can be allocated to several groups, and the system becomes messy.Optical Microscopes:These microscopes use visible light (or UV light in the case of fluorescence microscopy) to make an image. The light is refracted with optical lenses. The first microscopes that were invented belong to this category. The price of optical microscopes varies from very cheap to nearly unfordable (for the private person, at least). Optical microscopes can be further subdivided into several categories: Compound Microscope:These microscopes are composed of two lens systems, an objective and an ocular (eye piece). The maximum useful magnification of a compound microscope is about 1000x. Stereo Microscope(dissecting microscope): These microscopes magnify up to about maximum 100x and supply a 3-dimensional view of the specimen. They are useful for observing opaque objects. Confocal Laser scanning microscope:Unlike compound and stereo microscopes, these devices are reserved for research organizations. They are able to scan a sample also in depth. A computer is then able to assemble the data to make a 3D image.X-ray Microscope:As the name suggests, these microscopes use a beam of x-rays to create an image. Due to the small wavelength, the image resolution is higher than in optical microscopes. The maximum useful magnification is therefore also higher and is between the optical microscopes and electron microscopes. One advantage of x-ray microscopes over electron microscopes is, that it is possible to observe living cells.Scanning acoustic microscope (SAM):These devices use focused sound waves to generate an image. They are used in materials science to detect small cracks or tensions in materials. SAMs can also be used in biology where they help to uncover tensions, stress and elasticity inside biological structure.Scanning Helium Ion Microscope (SHIM or HeIM):As the name suggests, these devices use a beam of Helium ions to generate an image. There are several advantages to