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Period: Jan 1, 1580 to
Helmont's Experiements
Jan Baptist van Helmont (1580-1644) conducted several experiments that supported the idea of spontaneous genertaion. He claimed after his 5-year experiment on willow trees that the extra mass of the tree was spontaneously generated from another source. Holmost also created some recipes such as 21-day instructions to make mice in whihc dirty rags are placed in a dark corner. -
Redi's Experiement
Francessco Rei, an Italian scientist tested the theory of spontaneous generation by placing fresh meat in two different jars to create maggots. His experiment successfully demostrated that the maggots came from fly eggs and was one of the first to disprove spotaneous generation. -
Micheli Experiments with Fungal Spores and Melon
Pier Antonio Micheli experimented with fungal spores and melon slices and observed that fungi did not arise from spontaneous generation. -
Needham's Rebuttal
John Needham, an English scientist, challenged Redi's thoery by testing with gravy in enclosed bottles, then heating them to kill anything inside. His experiment reported that life had came from the broth days later; life had been created from nonlife. -
Spallanzani's Experiment
Another Itaian called Lazzro Spallanzani revisited Redi's and Needham's data. He stated that Needham did not het the bottle long enough to kill all te microbes. He backed this up with his own experiment with sealed bottles and his observations disproved spontaneous generation. Other scientist, however, noted that the experiemented bottles were deprived of air. They concluded that air was necessary for spontaneou generation and disregarded Spallanzani's claims. -
Experiments with Alcholic Fermentation
Charles Cagniard de la Tour and Theodor Schwann discovered yeart in alcholic fermentation. If yeast were not present, fermentation would not occur with sterile airor pur oxygen. This suggested that airbornedd microorganisms were the cause of fementation instead of spontaneous generation. -
Pasteur's Experiment
Louis Pasteur, a French scientist, challenged the theory that spontaneous generation relied on air. He designed swan-neck flasks that curved downward so gravity would prevent airborne foriegn materials from entering the bottle. Using this bottle, he conducted his own experiement ad finally convinced th world tht life did not arise from nonlife. -
Tyndall's Experiement
A conclusion on spontaneous generation was addd when John Tyndall reinforced Pastuear's research by experimenting with the environmental air of broths. His data extended the idea that biomass decomposition requires the presence of micro-organisms.
