History Of MicroBiology

Microscopes

First Use of a Microscope

1665

English scientist Robert Hooke used
a microscope, to investigate cork. He saw that cork resembled a
honeycomb. The cork was made of small boxes that
Hooke described as cellulae (a Latin word meaning
‘little storage rooms’)Hooke had discovered
cells. Cork cells are dead plant cells and
have nothing inside them; therefore
Hooke saw only cell walls

Its Upgrade Time

1931

German engineer
Ernst Ruska designed
and built the
first electron
microscope.
This allowed
scientists to see
even smaller
things such as
viruses, which
are too small
to be seen
using light
microscopes.

Making the Invisible, Visible

1935

However, it was
1935 before these agents were made visible using
an electron microscope and viruses were seen for
the first time.

Electron Microscope

1950

Since their invention, the magnification of electron
microscopes has improved and they are
now capable of magnifying an object
up to 1 000 000 times.

Cells

First Pond Water Sampled

1674

the Dutchman Antonie van
Leeuwenhoek used a microscope to look at pond
water and saw small things moving about. What he
was seeing were small, single-celled (unicellular) living
things. This made Leeuwenhoek the first person to
observe and describe microscopic living things.

Not Just Empty Boxes

1833

Scottish scientist
Robert Brown discovered that plant cells were not
just empty boxes but that they had a nucleus inside
them.

Building Blocks

1838

Matthias Schleiden, a German scientist,
analysed the known information about plant cells.
He proposed that cells are the basic building blocks
of all plants, and that new plants start off as a

Unit of life

1839

A year later a friend of Schleiden’s, Theodor
Schwann, proposed that all animals are made
of cells and that the cell is the basic unit of life.

Division of Cells

1842

Swiss scientist Karl Nägeli observed
cells dividing to make new cells. This was the first
time that scientists understood that new cells came
from existing cells.

Linking From the past

1855

German scientist Rudolf Virchow linked
the observations of Nägeli and Brown. He proposed
that all cells develop from existing cells and don’t
just spring up from nowhere.

'Invisible agents'

1898

It had been
known since
1898 that ‘invisible agents’ called viruses caused
diseases in plants and animals.