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.
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
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.
Working Distance• The distance between the objective lens andthe glass slide.• The higher the magnification, the less distancebetween the two.
Field of Vision• The surface area of the slide that can be seenthrough the microscope.• This decreases with increased magnification.
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).