Microscopes

Light Microscopes in Health and Hygiene

Microscopes have been around for hundreds of years. There are many different versions about who invented the first microscope. This site (http://inventors.about.com/od/mstartinventions/a/microscope.htm) says the first real microscope was invented around 1590 by two Dutch scientists, Zaccharias Janssen and Hans Janssen. They experimented placing multiple lenses in a metal tube and they realized that any objects would be magnified greatly if viewed through the lenses. However, this site (http://campus.udayton.edu/~hume/Microscope/microscope.htm) claims that the first microscope was developed in England in the 16th century although it does not say by who. Years later, in the 17th century, English physicist Robert Hooke viewed cork cells through a microscope and described them as “little boxes”. Also that century, Anton van Leeuwenhoek created a microscope with a single lens to view bacteria, yeast and insects. He was also the first person to describe bacteria as “little animalcules”.

There are three main types of microscopes; light microscopes, dissecting microscopes and electron microscopes. Dissecting microscopes are basically oversized magnifying glasses that are used to help scientists dissect specimens more accurately. Dissecting microscopes can achieve a magnification of about 20-50x. Electron microscopes, however, are much more powerful and can magnify objects 1,000,000 times. Electron microscopes use electrons in a vacuum instead of light to see the slide (Wikipedia, Electron Microscopes). They are so powerful they can see the diameter of single atom. The downside is that they are extremely expensive and very hard to set up and use properly. Specimens must be dead and coated with a metal like gold so that the electrons can bounce back better. Also, unlike light and dissecting microscopes, electron microscopes can only project the specimen in black and white.

The light microscope is an important tool in many... [continues]

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