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 MicroscopeParts and Functions
6. Labeling the Microscope
7. AThe 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 theimage
9. CFine Adjustment Knob • used to make fine movements of the body tube to sharpen the image
10. DObjective 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. EThe 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. FThe Arm • This supports the body tube. • One hand must be placed here to carry the microscope.
13. GThe Base • Supports the microscope • When moving the microscope, one hand must be underneath the base.
14. HThe 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 passesthrough the slide and lenses.• Can be twisted to increase or decrease thewidth of its opening
17. Power of Magnification• The relative enlargement of an specimen seenthrough a microscope.• Can be calculated - Power of the Eyepiece Lens XPower of the Objective Lens
18. Inversion• An image appears upside down through theeyepiece.• When the slide is moved to the right, it appearsin 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 andthe glass slide.• The higher the magnification, the less distancebetween the two.
20. Field of Vision• The surface area of the slide that can be seenthrough the microscope.• This decreases with increased magnification.
21. For Homework • Label the parts of the microscope • Take a look at the website online athttp://www.emsb.qc.ca/marymount/index.htm • Study for a microscope parts quiz on Friday, Sept. 9th (Day 6 last period).