History of the Microscope I Microscope An instrument

History of the Microscope

I. Microscope= An instrument that makes small objects look larger. A. The Inventors: 1. 1590 Hans & Zaccharius Janssen a. Dutch lens grinders b. made the 1 st compound microscope (has more than one lens)

2. 1609 Galileo a. b. Improved on the Janssen’s ideas Made a microscope that could be focused

3. Anton Van Leeuwenhoek 1632 -1723 a. b. c. Dutch scientist who greatly improved lens grinding 1 st to see bacteria, yeast, blood cells, and life in pond water Made people aware of microscopic life

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Leeuwenhoe k Unlikely ® scientist ®A tradesman (a fabric merchant, a surveyor, a wine assayer, and a minor city official) ® No university degrees ® Knew no language other than Dutch

…oh Leeuwenhoek ® But he had skill, he was hardworking, had an endless curiosity, and he kept an open mind ® His researches opened up the world of microscopic life to scientists

His Inspirations… ® Leeuwenhoek saw Robert Hooke’s illustrated book Micrographia which showed Hooke’s own observations with a microscope

Anton’s creations: ® Made over 500 simple “microscopes” ® Microscopes were simply powerful magnifying lenses ® Specimens were mounted on the sharp point that sticks up in front of the lens

Anton’s Microscopes: Compound microscopes invented around 1595 ® But could only magnify 20 -30 x ® But Leeuwenhoek’s simple microscope could magnify 200 x (what a great lens grinder)! ® Hired a skilled illustrator to draw the things he saw ®

All good researchers share their findings…. ® 1673 Leeuwenhoek began writing letters to the Royal Society of London describing what he’d seen with his microscopes

Eeeeewww… ® 17 September 1683 wrote about observations on his own plaque “a little white matter, which is as thick as if it ‘twere batter” ® Repeated observations on two men who had never cleaned their teeth ® Found “an unbelievingly great company of living animalcules, a-swimming more nimbly than any I had ever seen up to this time. Moreover…the animalcules… seemed to be alive. ”

WEE BEASTIES! ® These were the first observations of living bacteria ever recorded! ® He soon called them his “wee beasties”!

Oooh What He Saw! ®Foraminifera ®Blood cells

CONGRATULATIONS ANTON! ® After 50 years of writing to the Royal Society of London, he was elected a full member ® Joined Robert Hooke, Robert Boyle, Christopher Wren and other great scientists of his day

…Now, back to your notes…

B. Compound Light Microscope 1. 2. 3. 4. 5. Has two or more lenses Used to study cells Most magnify to 400 x Most powerful magnifies 2000 x Most have 3 objectives a. b. c. Low Medium High 6. Specimen MUST be thin (allows light to pass through)

C. Electron Microscope 1. 2. 3. 4. Uses electrons and magnets Very powerful – magnifies 2 million x or more Show specimens in 3 -D Requires TV to view image

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