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Aristotle's View on Spontaneous Generation
Legendary Greek scientist and philosopher Aristotle believed living things came forth from nonliving materials, as these nonliving things contained "vital heat" or "pneuma" He accmulated prevous century naturalists' work on the topic and presented his arguments in a book, "The History of Animals". -
Recipe for Mice
17th century physician and chemist Jean Baptiste van Helmont devised a home recipe for the manufacture of mice. He claimed that simply placing a soiled shirt in a vessel containing wheat would change the grains into mice. Helmont believed that the fumes from the wheat would trigger the transformation. This receipe was one of the many products of the theory of spontaneous generation. -
Maggots and Meat
Italian physician Francisco Redi performed an experiment regarding spontaneous generation by setting up 6 jars of decaying meat. He sealed 3 and kept the rest open. The sealed jars were unreachable to outside influence while the unsealed jars attracted flies, which laid eggs on the meat. After he observed maggots living in the unsealed jars, Redi believed he had defied the theory of spontaneous generation. However, supporters of the concept blamed the lack of fresh air in the sealed jar. -
Needham's Broth
English clergyman John Needham proposed the experiment of boiling broth to test the concept of spontaneous generation. He was aware that boiling substances killed microorganisms, and he was curious in knowing whether they "appeared spontaneously" after being boiled. His results showed that life did indeed arise in the boiled broth. Needham concluded that there was a "vegetative force" in every piece of matter. -
Spallanzani's Contradictions
John Needham's work with contradicted by Italian physiologist Lazzaro Spallanzani about twnety years after Needham's initial publication. Spallanzani repeated Needham's experiments but added the crucial step of sealing his containiners while boiing the substances. Since Needham's containers were unsealed, microorganizes could reenter the broth, leading Needham to believe that they had appeared spontaneously. Spallanzani's new discoveries led to years of scientific debate. -
Pasteur's Experiments
Louis Pasteur rejected the idea of spontaneous generation by conducting a series of experiments proving that a) microorganisms are present in the air and have the ability to contaminate solutions and b) air is unable to create microbes. The debate of spontaneous generation had become so heated that the Paris Academy of Sciences offered whomever could settle the argument a prize. Pasteur became the recipient of this prize after he published the results of his experiments in 1864.
