Editing Spontaneous generation (section)

===Pasteur and Tyndall===

[[File:Experiment Pasteur English.jpg|thumb|upright=1.2|[[Louis Pasteur]]'s 1859 experiment showed that a boiled nutrient broth did not give rise spontaneously to new life, but that if direct access to air was permitted, the broth decomposed, implying that small organisms (in modern terms, [[Endospore|microbial spores]]) had fallen in and started to grow in the broth.<ref name="Ball"/><ref name="TyndallFragments2"/> ]]

[[Louis Pasteur]]'s  experiment's in the late 1850's are widely seen as having settled the question of spontaneous generation.<ref>{{Cite web |url=https://www.immunology.org/pasteurs-col-de-cygnet-1859 |title=Pasteur's "col de cygnet" (1859) |website=www.immunology.org |publisher=[[British Society for Immunology]] |archive-url=https://web.archive.org/web/20190811175656/https://www.immunology.org/pasteurs-col-de-cygnet-1859 |access-date=August 11, 2019 |archive-date=11 August 2019 }}</ref> He boiled a meat broth in a [[swan neck flask]]; the bend in the neck of the flask prevented falling 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.<ref name="slowdeath" /> However, minority objections were persistent and not always unreasonable, given that the experimental difficulties were far more challenging than the popular accounts suggest. The investigations of the Irish physician [[John Tyndall]], a correspondent of Pasteur and an admirer of his work, were decisive in disproving spontaneous generation. All the same, Tyndall encountered difficulties in dealing with [[Endospore|microbial spores]], which were not well understood in his day. Like Pasteur, he boiled his [[microbiological culture|cultures]] to sterilize them, and some types of bacterial spores can survive boiling. The [[autoclave]], which eventually came into universal application in medical practice and microbiology to sterilise equipment, was introduced after these experiments.<ref name= "TyndallFragments2">{{cite book |last=Tyndall |first=John |author-link=John Tyndall |title=Fragments of Science |volume=2 |chapter=IV, XII, XIII |orig-year=1876–1878 |publisher=P. F. Collier |location=New York |date=1905 |url=https://archive.org/details/fragmenoscien02tyndrich }}</ref>

In 1862, the [[French Academy of Sciences]] paid special attention to the issue, establishing a prize "to him who by well-conducted experiments throws new light on the question of the so-called spontaneous generation" and appointed a commission to judge the winner.<ref>{{cite book |last1=Engelhardt |first1=Hugo Tristram |last2=Caplan |first2=Arthur L. |title=Scientific Controversies: Case Studies in the Resolution and Closure of Disputes in Science and Technology |url=https://books.google.com/books?id=6nkSX63VsLkC&pg=PA107 |year=1987 |publisher=Cambridge University Press |isbn=978-0-521-27560-6 |page=107}}</ref> Pasteur and others used the term ''biogenesis'' as the opposite of spontaneous generation, to mean that life was generated only from other life. Pasteur's claim followed the German physician [[Rudolf Virchow]]'s doctrine ''Omnis cellula e cellula'' ("all cells from cells"),<ref>{{cite book |last=Virchow |first=Rudolf |author-link=Rudolf Virchow |title=Die Cellularpathologie |language=de |trans-title=Cell Pathology |publisher=August Hirschwald |year=1859 |location=Berlin |url =https://archive.org/details/diecellularpatho00virc/ }}</ref> itself derived from the work of [[Robert Remak]].<ref>{{cite journal |last=Remak |first=Robert |date=1852 |title=Über extracellulare Entstehung thierischer Zellen und über Vermehrung derselben durch Theilung |language=de |trans-title=On the extracellular origin of animal cells, and their multiplication by division |journal=Archiv für Anatomie, Physiologie und Wissenschaftliche Medicin |volume=19 |pages=47–57}}</ref><ref name="slowdeath"/> After Pasteur's 1859 experiment, the term "spontaneous generation" fell out of favor. Experimentalists used a variety of terms for the study of the origin of life from nonliving materials. ''Heterogenesis'' was applied to the generation of living things from once-living organic matter (such as boiled broths), and the English physiologist [[Henry Charlton Bastian]] proposed the term ''archebiosis'' for life originating from non-living materials. Disliking the randomness and unpredictability implied by the term ''spontaneous generation'', in 1870 Bastian coined the term ''biogenesis'' for the formation of life from nonliving matter. Soon thereafter, however, the English biologist [[Thomas Henry Huxley]] proposed the term ''abiogenesis'' for this same process, and adopted ''biogenesis'' for the process by which life arises from existing life.<ref>{{cite book |last=Strick |first=James |title=Evolution & The Spontaneous Generation |chapter-url=https://books.google.com/books?id=yjKplNQv9zoC&pg=PR11 |access-date=August 27, 2012 |date= 2001 |publisher=Continuum International Publishing Group |isbn=978-1-85506-872-8 |pages=xi–xxiv |chapter=Introduction}}</ref>