The Microscope

History of the Microscope

Magnification (making things appear bigger) has been used for thousands of years. From the time of the Egyptians (1000BC) glass lenses have been used to see the microscopic world.

Late 17th CenturyAntonie van Leeuwenhoek made hisown simple microscopes. They hadonly one lens and they werehandheld. He drew manymicroscopic organisms, such asbacteria, although he didn’tknow what they were at thetime. He is consideredto be the father of microscopy.

Van Leeuwenhoek’s famous description of microbes in tooth plaque (Firstedition, Delft in Holland, 12 September 1683, to Francois Aston, Pag.11). Leeuwenhoek’s drawing of short rods of bacilli and bacteria, the spheres of micrococci, and the corkscrew spirillum.

"In the morning I used to rub my teeth with salt and rinse my mouth with water and after eating to clean my molars with a toothpick.... I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving. The biggest sort had a very strong and swift motion, and shot through the water like a pike does through the water; mostly these were of small numbers."Actually he estimated more bacteria in one single drop than the number

of inhabitants living in the Dutch Republic at that moment. He also observed that Vinegar and Alcohol could kill some bacteria in the mouth.

At the same time Robert Hooke used a

compound microscope to view cork cells

and living things.

1938-The Electron MicroscopeIn 1938 James Hillier and Albert Prebus,

graduate students at the University of

Toronto, produced the first functional

electron microscope. Modern electron

microscopes can magnify specimens up

to 10 million times!!!!!!!

Types of Microscopes

1) Simple Microscopes- have only one lens

Magnifying Glass Eye Glasses

2) Compound Microscope- uses 2 lenses to magnify the specimen (one in eyepiece, one near specimen)

*this is the type of microscope we will be using in class

3) Stereomicroscope- gives a 3-D image of the external parts of a specimen (has two eyepieces). This type of microscope is commonly uses during dissections.

4) Electron Microscope- This microscope uses beams of electrons to see the specimen. It can magnify things up to 10 million times. It is this type of microscope that allows us to see the organelles in a cell.

The Parts of a Compound Microscope

The compound microscope has many different parts that have many different purposes. The parts can fall into three different categories:

The Optical System- this is what actually magnifies and allows us to see the specimen

Optical lensObjective lens

The Light System- this is the light source of a microscope and what allows you to adjust the amount of light:

IlluminatorDisc Diaphragm

The Mechanical System- all other parts of the microscope fall under this category. The mechanical system allows you to focus the microscope and holds all the parts together.

ArmBaseCoarse and fine adjustment knobsStageStage clips