Maria Amparo Ruiz de Burton is known as one of the earliest Mexican-American authors published in English, and her life story is tied closely to the Mexican-American war and the establishment of California as a state.

Research:

• Amero, Richard W. “The Mexican-American War in Baja California.” The Journal of San Diego History. Winter 1984, Volume 30, Number 1. https://sandiegohistory.org/journal/1984/january/war/
• Annenberg Learner. “Maria Amparo Ruiz de Burton (c. 1832-1895).” https://www.learner.org/series/american-passages-a-literary-survey/masculine-heroes/maria-amparo-ruiz-de-burton-c-1832-1895/
• Brink, Jean R. “María Amparo Ruiz de Burton.” EBSCO Knowledge Advantage. 2023. https://www.ebsco.com/research-starters/history/maria-amparo-ruiz-de-burton
• Contreras, Alicia . "María Amparo Ruiz de Burton". In Oxford Bibliographies in American Literature. 3 Sep. 2025. https://www.oxfordbibliographies.com/view/document/obo-9780199827251/obo-9780199827251-0191.xml.
• Contreras, Alicia. "'I'll publish your cowardice all over California': Maria Amparo Ruiz de Burton's the squatter and the don in the age of Howells." American Literary Realism, vol. 49, no. 3, spring 2017, pp. 210+. Gale Academic OneFile, link.gale.com/apps/doc/A491311790/GPS?u=mlin_n_melpub&sid=bookmark-GPS&xid=97ad48d9. Accessed 28 Aug. 2025.
• Crawford, Kathleen. “María Amparo Ruiz Burton.” The Journal of San Diego History. Summer 1984, Volume 30, Number 3. https://sandiegohistory.org/journal/1984/july/burton/
• Diaz, Ella Maria. "Maria Amparo Ruiz de Burton: Critical and Pedagogical Perspectives." Legacy: A Journal of American Women Writers, vol. 22, no. 2, June 2005, pp. 202+. Gale OneFile: Business, link.gale.com/apps/doc/A141999447/GPS?u=mlin_n_melpub&sid=bookmark-GPS&xid=1c4826f6. Accessed 28 Aug. 2025.
• Dietrich, Lucas. “A Sensational Job: Maria Amparo Ruiz de Burton, J.B. Lippincott Co., and Commission Printing.” Bibliographical Society of America. Via YouTube. 4/19/2019. https://www.youtube.com/watch?v=Fb6sfXdUyR8
• Hedrick, Joan D. "Who Would Have Thought It?" The Women's Review of Books, vol. 13, no. 7, Apr. 1996, p. 6. Gale OneFile: Business, link.gale.com/apps/doc/A19140252/GPS?u=mlin_n_melpub&sid=bookmark-GPS&xid=c31ab587. Accessed 28 Aug. 2025.
• Meylor, Megan. “California Nerves.” Texas Studies in Literature and Language, FALL 2020, Vol. 62, No. https://www.jstor.org/stable/10.2307/27117136
• Quarstein, John V. “Worden and the Californios.” U.S. Naval Institute. October 2023. https://www.usni.org/magazines/naval-history-magazine/2023/october/worden-and-californios
• Raab, Josef. “The Imagined Inter-American Community of María Amparo Ruiz de Burton.” Amerikastudien / American Studies, 2008, Vol. 53, No. 1. Via JSTOR. https://www.jstor.org/stable/41158358
• Sánchez, Rosaura and Beatriz Pita, editors. “Conflicts of Interest: The Letters of María Amparo Ruiz de Burton.” Arte Publico Press. University of Houston. 2001.
• Spitzzeri, Paul R. “Article Ten of the Treaty of Guadalupe Hidalgo, 1848.” Homestead Museum Blog. 5/31/2019. https://homesteadmuseum.blog/2019/05/31/article-ten-of-the-treaty-of-guadalupe-hidalgo-1848/
• “María Amparo Ruiz, a woman of that century.” Issue 30. 3/8/2017. https://tendenciaelartedeviajar.com/en/2017/03/history/maria-amparo-ruiz-a-woman-of-that-century/
• University of Texas Press. “María Amparo Ruiz de Burton and the Conquered Californios: An Interview With Meagan Meylor.” 11/15/2021. https://utpress.utexas.edu/blog/2021/11/15/maria-amparo-ruiz-de-burton-and-the-conquered-californios-an-interview-with-meagan-meylor/
• Women & The American Story. “Life Story: María Ruiz de Burton (1832–1895).” The New York Historical Society. https://wams.nyhistory.org/industry-and-empire/expansion-and-empire/maria-ruiz-de-burton/

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Augustin Fresnel didn’t live a long life, but he contributed significantly to the understanding of light and to the safety of coastlines. Neither of those had anything to do with his career.

Research:

• Anderson, F.L. “Huygens' Principle geometric derivation and elimination of the wake and backward wave.” Sci Rep11, 20257 (2021). https://doi.org/10.1038/s41598-021-99049-7
• Aglialoro, Todd. “Jansenism.” Catholic.com. https://www.catholic.com/magazine/print-edition/jansenism
• Garcia-Atutxa, Igor, et al. “The epistemological impact of Augustin-Jean Fresnel and his wave theory of light in the 19th century.” History of Science and Technology. Vol. 14, No. 1. 2024. https://www.hst-journal.com/index.php/hst/article/view/616
• Clingan, Ian C.. "lighthouse". Encyclopedia Britannica, 17 Jan. 2025, https://www.britannica.com/technology/lighthouse
• Crew, Henry. “The wave theory of light; memoirs of Huygens, Young and Fresnel.” New York. Cincinnati American Book Company. 1900. Accessed online: https://archive.org/details/wavetheoryofligh00crewrich/page/n3/mode/2up
• Davidson, Michael W. “Augustin-Jean Fresnel (1788-1827).” Molecular Expressions. Florida State University. https://micro.magnet.fsu.edu/optics/timeline/people/fresnel.html
• The Editors of Encyclopaedia Britannica. "Augustin-Jean Fresnel". Encyclopedia Britannica, 11 Jul. 2025, https://www.britannica.com/biography/Augustin-Jean-Fresnel
• The Editors of Encyclopaedia Britannica. "François Arago". Encyclopedia Britannica, 22 Feb. 2025, https://www.britannica.com/biography/Francois-Arago
• “The Genius of Augustin-Jean Fresnel and his Lens.” Ponce Lighthouse & Museum. July 19, 2023. https://www.ponceinlet.org/the-genius-of-augustin-jean-fresnel-and-his-lens/
• Herivel, John. "Christiaan Huygens". Encyclopedia Britannica, 4 Jul. 2025, https://www.britannica.com/biography/Christiaan-Huygens.
• “July 1816: Fresnel’s Evidence for the Wave Theory of Light.” Advancing Physics. American Physical Society. https://www.aps.org/archives/publications/apsnews/201607/physicshistory.cfm
• Linden, Teri Clark. “A Short Bright Flash: Augustin Fresnel and the Birth of the Modern Lighthouse.” W.W. Norton. 2013.
• “May 1801: Thomas Young and the Nature of Light.” Advancing Physics. American Physical Society. https://www.aps.org/archives/publications/apsnews/200805/physicshistory.cfm
• “Napoleon’s Russian campaign: From the Niemen to Moscow.” Napoleon Foundation. https://www.napoleon.org/en/history-of-the-two-empires/timelines/napoleons-russian-campaign-from-the-niemen-to-moscow/
• Rehman, Ayaz Ur, and Muhammad Sabieh Anwar. “Light Is a Transverse Wave.” LUMS Syed Babar Ali School of Science and Engineering. August 21, 2018. https://physlab.org/wp-content/uploads/2018/08/LightTransverse-v2.pdf
• Silliman, Robert H. “Fresnel and the Emergence of Physics as a Discipline.” Historical Studies in the Physical Sciences , 1974, Vol. 4 (1974), pp. 137- University of California Press. https://www.jstor.org/stable/pdf/27757329.pdf
• Tag, Thomas. “Lens Use Prior to Fresnel.” United States Lighthouse Society. https://uslhs.org/node/1481

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This 2020 episode talks about how Pettenkofer's ideas about cholera's spread weren’t exactly right, but they still had really beneficial impacts on the way we live.

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Tracy talks about her background writing copy for sanitation and cleaning products. She and Holly also discuss how the implementation of the Wells' recommendations could have prevented a lot of illness.

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Husband-and-wife team William Firth Wells and Mildred Weeks Wells conducted research that had the potential to make a big difference in the safety of indoor air. But it didn’t really have a significant impact on public health.

Research:

• Associated Press. “Super-Oyster Is On its Way to Dinner Table Bigger and Better Bivalve Sports Pedigree.” 3/13/1927. https://www.loc.gov/resource/sn84020064/1927-03-13/ed-1/?sp=14
• “Brought Back to Texas.” The Houston Semi-Weekly Post. 12/26/1889. https://www.newspapers.com/image/1196039760/
• Decatur Daily Review. “Scientists Fight Flu Germs with Violet Ray.” 7/30/1936. https://www.newspapers.com/image/94335504/
• Evening Star. “Scientific Trap-shooter.” 6/26/1937. https://www.loc.gov/resource/sn83045462/1937-06-26/ed-1/?sp=7&q=William+Firth+Wells&r=0.668,0.557,0.438,0.158,0
• Fair, Gordon M. and William Weeks Wells. “Method and Apparatus for Preventing Infection.” U.S. Patent 2,198,867. https://ppubs.uspto.gov/api/pdf/downloadPdf/2198867
• Hall, Dominic. “New Center for the History of Medicine Artifact - Wells Air Centrifuge.” Harvard Countway Library. https://countway.harvard.edu/news/new-center-history-medicine-artifact-wells-air-centrifuge
• “Incubator Is Now Oyster Nurse.” Washington Times. 10/1/1925. https://www.loc.gov/resource/sn84026749/1925-10-01/ed-1/?sp=12
• Lewis, Carol Sutton. “Mildred Weeks Wells’s Work on Airborne Transmission Could Have Saved Many Lives—If the Scientific Establishment Listened.” Lost Women of Science Podcast. Scientific American. 5/22/2025. https://www.scientificamerican.com/article/a-public-health-researcher-and-her-engineer-husband-found-how-diseases-can/
• Library and Archives Team. “William Firth Wells and Mildred Weeks Wells.” Washington College. https://www.washcoll.edu/people_departments/offices/miller-library/archives-special-collections/archives-blog/Wells%20papers.php
• Molenti, Megan. “The 60-Year-Old Scientific Screwup That Helped Covid Kill.” Wired. 5/13/2021. https://www.wired.com/story/the-teeny-tiny-scientific-screwup-that-helped-covid-kill/
• Perkins JE, Bahlke AM, Silverman HF. Effect of Ultra-violet Irradiation of Classrooms on Spread of Measles in Large Rural Central Schools Preliminary Report. Am J Public Health Nations Health. 1947 May;37(5):529-37. PMID: 18016521; PMCID: PMC1623610.
• Randall, Katherine and Ewing, E. Thomas and Marr, Linsey and Jimenez, Jose and Bourouiba, Lydia, How Did We Get Here: What Are Droplets and Aerosols and How Far Do They Go? A Historical Perspective on the Transmission of Respiratory Infectious Diseases (April 15, 2021). Available at SSRN: https://ssrn.com/abstract=3829873
• Riley, Richard L. “What Nobody Needs to Know About Airborne Infection.” American Journal of Respiratory and Critical Care Medicine. Volume 163, Issue 1. https://www.atsjournals.org/doi/10.1164/ajrccm.163.1.hh11-00
• Simon, Clea. “Did a socially awkward scientist set back airborne disease control?” The Harvard Gazette. 3/7/2025. https://news.harvard.edu/gazette/story/2025/03/did-a-socially-awkward-scientist-set-back-airborne-disease-control/
• “Texas State News.” McKinney Weekly Democrat-Gazette. 4/17/1890. https://www.newspapers.com/image/65385350/
• WELLS MW, HOLLA WA. VENTILATION IN THE FLOW OF MEASLES AND CHICKENPOX THROUGH A COMMUNITY: Progress Report, Jan. 1, 1946 to June 15, 1949, Airborne Infection Study, Westchester County Department of Health. JAMA. 1950;142(17):1337–1344. doi:10.1001/jama.1950.02910350007004
• WELLS MW. VENTILATION IN THE SPREAD OF CHICKENPOX AND MEASLES WITHIN SCHOOL ROOMS. JAMA. 1945;129(3):197–200. doi:10.1001/jama.1945.02860370019006
• WELLS WF, WELLS MW. AIR-BORNE INFECTION. JAMA. 1936;107(21):1698–1703. doi:10.1001/jama.1936.02770470016004
• WELLS WF, WELLS MW. AIR-BORNE INFECTION: SANITARY CONTROL. JAMA. 1936;107(22):1805–1809. doi:10.1001/jama.1936.02770480037010
• Wells, W F, and M W Wells. “Measurement of Sanitary Ventilation.” American journal of public health and the nation's health vol. 28,3 (1938): 343-50. doi:10.2105/ajph.28.3.343
• Wells, William Firth and Gordon Maskew Fair. Viability of B. coli Exposed to Ultra-Violet Radiation in Air.Science82,280-281(1935).DOI:10.1126/science.82.2125.280.b
• Wells, William Firth and Mildred Weeks Wells. Measurement of Sanitary Ventilation American Journal of Public Health and the Nations Health 28, 343_350, https://doi.org/10.2105/AJPH.28.3.343
• Zimmer, Carl. “Air-Borne: The Hidden History of the Life We Breathe.” Dutton. 2025.

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All over the world, for all of human history – and probably going back to our earliest hominid ancestors – people have found ways to try to keep themselves clean. But how did soap come about?

Research:

• “Soap, N. (1), Etymology.” Oxford English Dictionary, Oxford UP, June 2025, https://doi.org/10.1093/OED/1115187665.
• American Cleaning Institute. “Soaps & Detergents History.” https://www.cleaninginstitute.org/understanding-products/why-clean/soaps-detergents-history
• Beckmann, John. “History of Inventions, Discoveries and Origins.” William Johnston, translator.
• Bosart, L.W. “The Early History of the Soap Industry.” The American Oil Chemists' Society. Journal of Oil & Fat Industries 1924-10: Vol 1 Iss 2.
• Cassidy, Cody. “Who Discovered Soap? What to Know About the Origins of the Life-Saving Substance.” Time. 5/5/2020. https://time.com/5831828/soap-origins/
• Ciftyurek, Muge, and Kasim Ince. "Selahattin Okten Soap Factory in Antakya and an Evaluation on Soap Factory Plan Typology/Antakya'da Bulunan Selahattin Okten Sabunhanesi ve Sabunhane Plan Tipolojisi Uzerine Bir Degerlendirme." Art-Sanat, no. 19, Jan. 2023, pp. 133+. Gale Academic OneFile, dx.doi.org/10.26650/artsanat.2023.19.1106544. Accessed 18 Aug. 2025.
• Costa, Albert B. “Michel-Eugène Chevreul.” Encyclopedia Britannica. https://www.britannica.com/biography/Michel-Eugene-Chevreul
• Curtis, Valerie A. “Dirt, disgust and disease: a natural history of hygiene.” Journal of epidemiology and community health vol. 61,8 (2007): 660-4. doi:10.1136/jech.2007.062380
• Dijkstra, Albert J. “How Chevreul (1786-1889) based his conclusions on his analytical results.” OCL. Vol. 16, No. 1. January-February 2009.
• Gibbs, F.W. “The History and Manufacture of Soap.” Annals of Science. 1939.
• Koeppel, Dan. “The History of Soap.” 4/15/2020. https://www.nytimes.com/wirecutter/blog/history-of-soap/
• List, Gary, and Michael Jackson. “Giants of the Past: The Battle Over Hydrogenation (1903-1920).” https://www.ars.usda.gov/research/publications/publication/?seqNo115=210614
• Maniatis, George C. “Guild Organized Soap Manufacturing Industry in Constantinople: Tenth-Twelfth Centuries.” Byzantion, 2010, Vol. 80 (2010). https://www.jstor.org/stable/44173107
• National Museum of American History. “Bathing (Body Soaps and Cleansers).” https://americanhistory.si.edu/collections/object-groups/health-hygiene-and-beauty/bathing-body-soaps-and-cleansers
• New Mexico Historic Sites. “Making Soap from the Leaves of the Soaptree Yucca.” https://nmhistoricsites.org/assets/files/selden/Virtual%20Classroom_Soaptree%20Yucca%20Soap%20Making.pdf
• “The history of soapmaking.” 8/30/2019. https://www.open.edu/openlearn/history-the-arts/history/history-science-technology-and-medicine/history-science/the-history-soapmaking
• Pliny the Elder. “The Natural History of Pliny. Translated, With Copious Notes and Illustrations.” Vol. 5. John Bostock, translator. https://www.gutenberg.org/files/60688/60688-h/60688-h.htm
• Pointer, Sally. “An Experimental Exploration of the Earliest Soapmaking.” EXARC Journal. 2024/3. 8/22/2024. https://exarc.net/issue-2024-3/at/experimental-exploration-earliest-soapmaking
• Ridner, Judith. “The dirty history of soap.” The Conversation. 5/12/2020. https://theconversation.com/the-dirty-history-of-soap-136434
• Routh, Hirak Behari et al. “Soaps: From the Phoenicians to the 20th Century - A Historical Review.” Clinics in Dermatology. Vol. No. 3. 1996.
• Smith, Cyril Stanley, and John G. Hawthorne. “Mappae Clavicula: A Little Key to the World of Medieval Techniques.” Transactions of the American Philosophical Society, vol. 64, no. 4, 1974, pp. 1–128. JSTOR, https://doi.org/10.2307/1006317. Accessed 18 Aug. 2025.
• Timilsena, Yakindra Prasad et al. “Perspectives on Saponins: Food Functionality and Applications.” International journal of molecular sciences vol. 24,17 13538. 31 Aug. 2023, doi:10.3390/ijms241713538
• “Craftsmanship of Aleppo Ghar soap.” https://ich.unesco.org/en/RL/craftsmanship-of-aleppo-ghar-soap-02132
• “Tradition of Nabulsi soap making in Palestine.” https://ich.unesco.org/en/RL/tradition-of-nabulsi-soap-making-in-palestine-02112
• “Soaps.” https://www.fs.usda.gov/wildflowers/ethnobotany/soaps.shtml
• van Dijk, Kees. “Soap is the onset of civilization.” From Cleanliness and Culture. Kees van Dijk and Jean Gelman Taylor, eds. Brill. 2011. https://www.jstor.org/stable/10.1163/j.ctvbnm4n9.4
• Wei, Huang. “The Sordid, Sudsy Rise of Soap in China.” Sixth Tone. 8/11/2020. https://www.sixthtone.com/news/1006041

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This 2021 episode covers John Dalton, famous for his work in atomic theory. But he wrote one of the first thorough descriptions of what he called “anomalous vision” – he realized he wasn’t perceiving color the same way as other people.

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Holly talks about nebulous passages in the writing of Jane Croly and her brother. Tracy and Holly talk about watching TV as children.

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