Download How did scientists discover the cause of disease?

 starter activity
Casu marzu is a cheese made from unpasteurised goat’s milk. The cheese is left exposed so that a special cheese fly can
lay its eggs on the cheese. The maggots hatch and eat the cheese helping to breakdown the fats and start the
fermentation process. The cheese becomes very soft and liquid called lagrima seeps out. The maggots grow to about
8 millimetres long. When disturbed, they can launch themselves for distances up to 15 centimetres. The idea is you eat
the cheese, maggots and all!
How did scientists
discover the cause of
 Aims
disease?
To explore the origins of germ theory & the
work of Louis Pasteur
 Your task

Read p. 128. Find out what a miasma was.
‘Miasmists’ toured British
cities sniffing out evilsmelling quarters and
informing the authorities of
the health hazard
What was a ‘miasma’?




Common sense told people there was a
connection between dirt & disease
Miasma – poisonous fumes give off by decaying
matter
Strong-smelling herbs & spices countered the
effects
Ventilated hospitals improved chances of
survival
 Your task





Reading for gist. Read pp. 128-9 about the discovery of
micro-organisms. You don’t need to take notes!
What contribution did the following men make to the
discovery of the causes of disease?
Anthony van Leeuwenhoek
Joseph Lister
Louis Pasteur
 Your task

Imagine you have been asked to produce a film
explaining the discovery of the causes of
disease. You will be given a template for a
storyboard. Sketch an image in each box
showing the main stages in the discovery. The
first box can provide the background and the
last one can be the credits!
 Your task



Listen to the interview with Robert Koch, the
scientist who developed Pasteur’s experiments
into bacteria and developed theories on how
they caused disease in humans and animals.
How did he help the development of germ
theory?
What was secret of his success?
Koch’s contribution to germ theory



Identified the bacterium caused anthrax
Other bacteria, e.g. typhoid, TB, cholera identified in
same way
Developed a technique to cultivate bacteria and used
dyes to make them visible
Secret of his success



Built on previous
knowledge (Pasteur &
Co.)
Repeated experiments to
check results (through 20
generations of mice)
Improved testing
technology, e.g.
developing cultures &
dyes
Robert Koch, German scientist
in his laboratory
 Your task

Read pp. 130-1 and create a spider diagram
identifying the reasons why diseases were
discovered at this time. Include the following
categories: observation, new technology, medical
knowledge, research teams, individual genius,
chance, governments, warfare, other reasons
Reasons for the discovery of diseases



Observation – P conducted experiments using
sterile flasks in different locations, identifying
that particles in air caused decay
New technologies – K developed better ways of
growing bacteria & stains to identify them; P &
K used new microscope developed by Lister
Medical Knowledge – P called his method of
immunising chickens against cholera
‘vaccination’ after Jenner
Reasons for the discovery of diseases



Research teams – P used teams of vets &
doctors
Individual genius – P said, ‘chance favours the
mind which is prepared’
Chance – chicken cholera solution left exposed
showed that germs were weakened by exposure
to air



Governments – P received money from French
govt
Warfare - rivalry between Fr & Germany
spurred on new discoveries
Other reasons – better communications;
pressure to improve agriculture led to anthrax
vaccine
 Plenary

What do you think was the most important
factor contributing to the development of germ
theory?