54
T
he development of the
compound microscope
in the 17th century
opened up a whole new world
of previously unseen structures.
A simple microscope consists of
just one lens, while the compound
microscope, developed by Dutch
eyeglasses makers, uses two
or more lenses, and generally
provides greater magnification.
English scientist Robert Hooke
was not the first to observe living
things using a microscope.
However, with the publication
of his Micrographia in 1665, he
became the first best-selling
popular science author, stunning
his readers with the new science of
microscopy. Accurate copperplate
drawings made by Hooke himself
showed objects the public had
never seen before—the detailed
anatomies of lice and fleas; the
compound eyes of a fly; the delicate
wings of a gnat. He also drew some
man-made objects—the sharp
point of a needle appeared blunt
under the microscope—and used
his observations to explain howcrystals form and what happens
when water freezes. The English
diarist Samuel Pepys called
Micrographia “the most ingenious
book that I ever read in my life.”Describing cells
One of Hooke’s drawings was of a
thin slice of cork. In the structure
of the cork, he noted what looked
like the walls dividing monks’ cells
in a monastery. These were the first
recorded descriptions and drawings
of cells, the basic units from which
all living things are made. ■ALL LIVING THINGS
ARE COMPOSED
OF CELLS
ROBERT HOOKE (1635 –1703)
Hooke’s drawings of dead cork cells
show empty spaces between the cell
walls—living cells contain protoplasm.
He calculated that there were more than
a billion cells in 1 in^3 (16 cm^3 ) of cork.IN CONTEXT
BRANCH
BiologyBEFORE
c.1600 The first compound
microscope is developed in
the Netherlands, probably
by either Hans Lippershey or
Hans and Zacharius Janssen.1644 Italian priest and self-
taught scientist Giovanni
Battista Odierna produces
the first description of living
tissue, using a microscope.AFTER
1674 Antonie van
Leeuwenhoek is the first to see
single-celled organisms under
the microscope.
1682 Van Leeuwenhoek
observes the nuclei inside the
red blood cells of salmon.1931 The invention of the
electron microscope by
Hungarian physicist Leó
Szilárd allows much higher
resolution images to be made. See also: Antonie van Leeuwenhoek 56–57 ■ Isaac Newton 62–69 ■
Lynn Margulis 300–01