Louis Pasteur's experiments Hello, today I'd like to talk about Louis Pasteur and his work to deny 'spontaneous generation'. 'Spontaneous generation' was proposed by Aristotle in the 4th century B.C. 'Spontaneous generation' means that living things come from inanimate objects naturally. Also, it had been believed by people all over the world until 16th century. In 1668, Francesco Redi made an experiment to try to deny 'spontaneous generation'. However, it was not sufficient. Also, by the discovery of microorganisms, it became difficult to deny it completely. In 1861, Louis Pasteur made an experiment to research relationship between the change of organic material solution and the growth of microorganisms. How can 'spontaneous generation' be disproved? In 1861, Pasteur conducted an experiment. 1. He put the air into the tube which is plugged with cotton. After that, microorganisms attached to the cotton. 2. Microorganisms didn't grow in organic material solution which included heating air. However, they grew in organic material solution which included the cotton. 3. He made the flask as shown in the figure. He added this solution in the flask and microorganisms didn't grow. However he broke a thin tube of the flask, microorganisms grew. Pasteur's work was a tremendous success. He denied 'spontaneous generation' by the experiments. After that, Tyndall made up for this experiments and 'spontaneous generation' was denied completely.