The document summarizes the history and key parts of the microscope. It discusses how Hans and Zaccharias Janssen discovered that lenses could magnify objects in 1590. Galileo then created a better instrument that could focus in 1609. Anton Van Leeuwenhoek then built an even better microscope in 1674 and was the first to observe bacteria. The document then describes the main parts of the microscope including the eyepiece, adjustment knobs, objective lenses, stage, arm, base, mirror, and diaphragm. It provides definitions and explanations for key microscope terms such as magnification, inversion, working distance, and field of vision.

1. The Microscope

2. A Microscopic History

3. 1590 - Hans and Zaccharias Janssen discovered that lenses in a
tube made objects appear much larger.
1609 - Galileo created a better instrument that could focus.
1674 - Anton Van Leeuwenhoek builds an even better microscope
and is the first to see bacteria.

4. Anton Van Leeuwenhoek

5. The Microscope
Parts and Functions

6. Labeling the Microscope

7. A
The Eyepiece
• A lens that magnifies the image made by the
objective lens.

8. B
Coarse Adjustment Knob
• moves the body tube up and down to focus the
image

9. C
Fine Adjustment Knob
• used to make fine movements of the body tube
to sharpen the image

10. D
Objective Lenses
• These are the lenses that provide for the magnification
of the image.
• There is a high powered lens and a low powered lens
that are held on a turret or nosepiece.

11. E
The Stage
• This is where the slide is held so that it can be viewed.
• There are stage clips on the stage that hold the slide
in place.

12. F
The Arm
• This supports the body tube.
• One hand must be placed here to carry the
microscope.

13. G
The Base
• Supports the microscope
• When moving the microscope, one hand must
be underneath the base.

14. H
The Mirror
• This directs light up through the hole in the
stage (diaphragm) through the slide and the
objective lenses.

15. The Diaphragm
• Controls the amount of light that passes
through the slide and lenses.
• Can be twisted to increase or decrease the
width of its opening

16. Terms

17. Power of Magnification
• The relative enlargement of an specimen seen
through a microscope.
• Can be calculated - Power of the Eyepiece Lens X
Power of the Objective Lens

18. Inversion
• An image appears upside down through the
eyepiece.
• When the slide is moved to the right, it appears
in the eyepiece to move to the left.
• When the slide is moved upwards on the stage,
it appears to move to the bottom of the view.

19. Working Distance
• The distance between the objective lens and
the glass slide.
• The higher the magnification, the less distance
between the two.

20. Field of Vision
• The surface area of the slide that can be seen
through the microscope.
• This decreases with increased magnification.

21. For Homework
• Label the parts of the microscope
• Take a look at the website online at
http://www.emsb.qc.ca/marymount/index.htm
• Study for a microscope parts quiz on Friday,
Sept. 9th (Day 6 last period).