Germs are regarded today with a combination of fear and disgust. But mankind’s first introduction to the microbial world started off on a very different foot. In this episode, as part of a larger series contextualizing germ theory, we’ll talk about the discovery of animalcules and how they forever changed our conception of the natural world -- and what causes disease. Plus, a new #AdamAnswers about the influence of Bayes Theorem on medicine!   Sources: Albury WR, Marie-Francois-Xavier Bichat, Encyclopedia of Life Science, 2001.  Ball CS, The Early History of the Compound Microscope, Bios, Vol 37, No2 (May 1966). Findlen P, Athanasius Kircher: The Last Man Who Knew Everything.  Feinstein AR, “An Analysis of Diagnostic Reasoning,” Yale Journal of Biology and Medicine, 1973. Forsberg L.Nature's Invisibilia: The Victorian Microscope and the Miniature Fairy, Victorian Studies 2015. Gest H. The discovery of microorganisms by Robert Hooke and Antoni van Leeuwenhoek, Fellows of The Royal Society. Notes and Records of the Royal Society of Lond, 2004.  Hall, GH, The Clinical Application of Bayes Theorem, The Lancet, September 9, 1967.  Howard-Jones N, Fracastoro and Henle: A Re-Appraisal of their Contribution to the Concept of Communicable Diseases,” Medical History, 1977, 21: 61-68. Lane N, The unseen world: reflections on Leeuwenhoek (1677) ‘Concerning little animals’. Philosophical Transactions of the Royal Society, 19 April 2015.  Lawson I, Crafting the microworld: how Robert Hooke constructed knowledge about small things, Notes and Records of the Royal Society of Lond, 2015. McLeMee S, Athanasius Kirchehr, Dude of Wonders, The Chronicle of Higher Education, May 28, 2002.  Van Leeuwenhoek A, Observations, communicated to the publisher by Mr. Antony van Leewenhoeck, in a dutch letter of the 9th Octob. 1676. here English'd: concerning little animals by him observed in rain-well-sea- and snow water; as also in water wherein pepper had lain infused (https://royalsocietypublishing.org/doi/10.1098/rstl.1677.0003) “Little worms which propagate plague,” J R Coll Physicians Edinb, 2008.  Van Zuylen J, “The microscopes of Antoni van Leeuwenhoek,” Journal of Microscopy., 1981. Music from https://filmmusic.io, "Wholesome," “Pookatori and Friends,” and by Kevin MacLeod (https://incompetech.com). License: CC BY