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Francesco Redi experiment
Rotting meat in open containers attracted flies, and was soon swarming with maggots. Jars were tightly covered so that flies could not get in, no maggots were produced. To answer the objection that the cover cut off fresh air necessary for spontaneous generation, covered the jars with several layers of porous gauze. Flies were attracted to the smell of the rotting meat, clustered on the gauze, which was soon swarming with maggots, but the meat remained free of maggots.Fies don't arise from meat. -
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Francesco Redi
Italy's Tuscany region is where Francesco Redi was born. Francesco's mother was Cecilia de Ghinci, and his father was distinguished physician Gregorio Redi, a nobleman by birth. He was a creative poet, physician, and scientist. His efforts produced a number of important landmarks. He demonstrated that flies do not naturally arise in inanimate objects and do not reproduce or lay eggs. He created and carried out the very first controlled experiments in the annals of science. -
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John Needham
London-born and Brussels-deceased English naturalist. He received his education at Duai, was ordained as a priest, and then started using a microscope to conduct study. As a result of his findings, he came to support the hypothesis of spontaneous generation. In his day, his intellectual prowess brought him great acclaim. He was admitted to the Royal Society of London (1746), the Academy of Sciences in Paris, and in 1769, Empress Maria Teresa invited him to lead the Academy in Brussels. -
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Lazzaro Spallanzani
Considered one of the founders of experimental biology, research focuses on the main life phenomena, such as respiration, reproduction or digestion. The son of a lawyer, was assigned by his father to the legal profession and to the religious state; However, he received his passion for natural sciences from his cousin Laura Bassi. Obtained permission from his father to stop studying law, he received holy orders and taught logic, metaphysics and Greek at the Jesuit college in Reggio. -
Needham's rebuttal
He placed broth into a bottle, heated the bottle to kill anything inside, then, after it had cold, he sealed it.
Days later he reported the presence of life in the broth and announced that life had been created from non-living matter. -
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Louis Pasteur
Was a French chemist whose discoveries were of enormous importance in various fields of the natural sciences, especially chemistry and microbiology. He invented the technique pasteurization. He was not a promising student in the natural sciences, in fact his interest was in the artistic area of painting. His first ambition was to be an art teacher. In 1842, after being a teacher at the Royal School of Besançon, he obtained his baccalaureate degree, with a poor qualification in chemistry. -
Pasteur puts spontaneous generation to rest
Re-create the experiment and leave the system open to air. Designed several bottles with S-curved necks that were oriented downward. He placed a cell broth in one of the swan-neck bottles, boiled the broth it, and observed no life in the jar for one year. He then broke off the top of the bottle, exposing it more directly to the air and trapped particles, noted life forms in the broth within days. He reasoned that the contamination came from life forms in the air, not a supposed “life force”. -
Criticism from Spallanzani
Spallanzani poured broth into flasks and sealed them. Next, he boiled the flasks for a long time, to kill present microorganisms.
After some time, the broth did not have any trace of life. However, once he unsealed the flask, microorganisms rapidly grew in the broth.
Spallanzani concluded that spontaneous generation was false and microbes came from contaminated air.