Louis Pasteur finally figures out how diseases are spread The Germ Theory Louis Pasteur finally figures out how diseases are spread

Existing Theories Miasma & Spontaneous Generation Disease carried by foul air Micro-organisms are the result of the process of decay Pus and gangrene mutates into Germs Flies and Maggots provided evidence Non-life creates living organisms

Micro-Organisms Leeuwenhoek He did not know what function they played Dutch clockmaker Built an early powerful microscope Examined everything he could He kept on noticing small living organisms in everything he examined In food, water, excreta, plaque He did not know what function they played

Improved Microscopes Joseph Lister in the 1830s Improved lens production allowed Joseph Lister to produce microscopes that could magnify 1,000 times Any scientist could buy this microscope Micro-organisms could be studied in more detail

Pasteur’s Germ Theory Pasteur Brewery in France His theory A Scientist (not a doctor) Brewery in France Asked Pasteur to investigate why some vats of alcohol would go bad His theory Germ = Germination A growing, living organism caused the problem His solution to the problem was to boil the liquid to kill the germs Pasteurisation Applied to milk, beer, wine, vinegar

Pasteur battles Spontaneous Generation Theory French Academy launches competition to prove or disprove Spontaneous Generation in 1860 Pasteur devises experiments to show that microbes existed in the air Copy source 2 page 129

Linking Germs to Disease “If wine and beer are changed by germs, then the same can and must happen sometimes in men and animals” French Silk Industry Asked Pasteur to investigate why their silkworms kept dying. He discovered that a certain germ was responsible for

Factors that helped development Task page 129 Draw a flow chart to show how germs were linked to disease Explain why each step was important What factors helped the scientists at each step. Homework Task Step Brief Description Why was it Important? Factors that helped development Suitable Image