The document provides a historical overview of the microscope, highlighting key inventors and advancements, including Hans and Zacharias Janssen's creation of the first compound microscope in 1590 and Anton van Leeuwenhoek's significant contributions in the 17th century, which included discovering bacteria. It explains the evolution of microscopes, detailing types such as the compound light microscope and the electron microscope, including their magnification capabilities and uses. Leeuwenhoek's observations opened up the world of microscopic life, leading to his membership in the Royal Society of London after decades of correspondence.

1. History of the
Microscope

2. 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 1st
compound
microscope (has more than
one lens)

3. 2. 1609 Galileo
a. Improved on the
Janssen’s ideas
b. Made a
microscope that
could be focused

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

5. And now, time out
for a word from
your sponsor….

6. 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

7. …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

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

9. 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

10. 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

11. 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

12. 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.”

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

14. Oooh What He Saw!
Foraminifera
Blood cells

15. 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

16. …Now, back to
your notes…

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

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

19. Congratulations!
You’re finished.