Timeline Session 3

Francesco Redi was an Italian scientist. He is known for doing an experiment against the theory of spontaneous generation. His experiment was based on the idea that worms were generated from rotten meat. To verify that it was false, he put meat in several jars and sealed some and left some open.
The results he got were what he expected, the jars that were open had worms. He believed that this disproven spontaneous generation, however, simply proved that the worms did not come from meat.

Lazzaro Spallanzani was an Italian scientist, who performed Needham's sauce experiment but modified it, and designed his own experiment. You boiled sauce in two different bottles, then seal one bottle and leave the other open. He realized that the unsealed bottle contained small living things, but the sealed one showed no signs of life. It just showed that the theory needs air to work.

John Needham, was an English scientist, who also wanted to refute the theory of spontaneous generation. He conducted an experiment by putting sauce in a bottle. When he boiled and put sauce in a bottle, he heated it to kill the living organisms inside and days later, he noticed the presence of microbes in the sauce showing that life can be created from inorganic matter.

Louis Pasteur, was a prominent French scientist who performed a combination with the Needham and Spallazani experiments, but left the bottles open to the air. He designed a bottle with a curved neck in S so that gravity would prevent the access of the materials in the air and he followed the same procedure as them. He discovered that although the sauce could enter the air, it did not develop life, thus he showed that the microbes were born from the air.