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History of the Microscope. 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. Improved on the Janssen’s ideas
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Microscope= An instrument that makes small objects look larger. A. The Inventors: 1. 1590 Hans & Zaccharius Janssen a. Dutch lens grinders b. made the 1st compound microscope (has more than one lens)
2. 1609 Galileo • Improved on the Janssen’s ideas • Made a microscope that could be focused
3. Anton Van Leeuwenhoek 1632-1723 • Dutch scientist who greatly improved lens grinding • 1st to see bacteria, yeast, blood cells, and life in pond water • Made people aware of microscopic life
Leeuwenhoek • 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 20-30x • But Leeuwenhoek’s simple microscope could magnify 200x (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
B. Compound Light Microscope • Has two or more lenses • Used to study cells • Most magnify to 400x • Most powerful magnifies 2000x • Most have 3 objectives • Low • Medium • High 6. Specimen MUST be thin (allows light to pass through)
C. Electron Microscope • Uses electrons and magnets • Very powerful – magnifies 2 million x or more • Show specimens in 3-D • Requires TV to view image