Download The Microscope

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 Century
Antonie van Leeuwenhoek made his
own simple microscopes. They had
only one lens and they were
handheld. He drew many
microscopic organisms, such as
bacteria, although he didn’t
know what they were at the
time. He is considered
to be the father of microscopy.
Van Leeuwenhoek’s famous description of microbes in tooth plaque (First
edition, 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 Microscope
In 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 lens
Objective lens
The Light System- this is the light source of a microscope and
what allows you to adjust the amount of light:
Illuminator
Disc 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.
Arm
Base
Coarse and fine adjustment knobs
Stage
Stage clips