-
100
Hypothesis
People believed that organic matter can createliving organisms from inanimate objects. This was a popularized in the Middle Ages as it proves the religious views of how god created the universe. The theory however, existed long before, during the greek times -
The Redi Experiment
Francesco Redi conducted an experiment to contradict the hypothesis. He was able to prove that the maggot "spontaneously generating" were from the flies that laid eggs on the meat. Despite this experiment, Redi himself believed that spontaneous generationg could occur in other circumstances. -
Needham
It was widely known at the time that heat killed organisms. John Needham, to prove the existance of Spontaneous Generation, boiled broth killing the licing organisms and then left it out it the air. Obviously after cooling, a layer of microorganisms appeared. This was proof enough for Needham.. -
Spallanzani
To disprove Needham, his experiment was repeated by Lazzaro Spallanzani except this time Spallanzani did not let the broth come into contact with air. There was no growth in Spallanzani's flask. -
Louis Pasteur
Pasteur was able to finally settle the debate between Needham and Spallanzani. He proved the existence of microorganisms in the air using gun cotton filters. -
The Swan Neck Flask Experiment
Louis Pasteur conducted an experiment against the hypothesis using heated broth. His experiment was similar to Needham's but instead of just leaving the flask open, he melted down the lip into the shape of the swan neck thus preventing microorganisms in the air from easily entering the flask but still allowing airflow. No organisms appeared until he broke the neck. -
Thomas H. Huxley
Thomas H. Huxley gives his "Biogenesis and Abiogenesis" lecture supporting Louis Pasteur's theories also disproving spontaneous regeneration. -
John Tyndall
John Tyndall published his method for fractional sterilization, showing the existence of heat-resistant bacterial spores. He proved that boiling does not kill these spores and their presence in chicken broth, as well as other foods explains the results of Needham's experiments.
