-
Redi’s experiment
The experiment of Francesco Redi consisted in 3 experimental conditions:
1:Open jars =the flies eat the meat, and the flies lay eggs, and life comes from the remaining meat.
2. Tightly sealed jars = flies don’t have access so new life doesn't appear.
3. Jars covered with clothes= flies don’t have access so new life doesn't appear. -
Needham’s rebuttal
The experiment consisted of heating opened flasks with broth for killing the microorganisms. After boiling the flasks he sealed them, but after some time the microorganisms reappeared -
Criticism from Spallanzani
He didn't agree with Needham’s conclusions so he did almost the same experiment as John Needham, but with some differences.
The difference is that when Spallanzani boiled the flasks he did it for a longer time and put a cork on the pot. This prevented microorganisms from entering the flask. -
Pasteur's experiment
Louis Pasteur re-created the experiment and leave the system open to the air. He did the experiment using flasks with S-curved necks to prevent the fallen particles from reaching the broth, while still allowing the free flow of air. The flask remained free of growth for an extended period. When the flask was turned so that particles could fall down the bends, the broth quickly became clouded.
