The first population study in history was born out of a dramatic debate involving leeches, "medical vampires," professional rivalries, murder accusations, and, of course, bloodletting, all in the backdrop of the French Revolution. The second of a multipart series on the development of population medicine, this episode contextualizes Pierre Louis' "numerical method," his famous trial on bloodletting, and the birth of a new way for doctors to "know". Plus a brand new #AdamAnswers about Occam's razor and Hickam's Dictum. All this and more on Episode 38 of Bedside Rounds, a tiny podcast about fascinating stories in clinical medicine! To claim CME and MOC credit, please go to www.acponline.org/BedsideRounds.

• Best M and Neuhauser D, "Pierre Charles Alexandre Louis: Master of the spirit of mathematical clinical science," Qual Saf Health Care 2005;14:462–464.
• Duffin J, "Laennec and Broussias: The 'Sympathetic' Duel," from La Berge A and Hannaway C, Paris Medicine: Perspective Past and Present.
• (1977) The French Revolution: A Revolution in Medicine, Too, Hospital Practice, 12:11, 127-138
• Hillard A, et al. "Occam's Razor versus Saint's Triad, N Engl J Med 2004;350:599-603.
• Lo Re V 3rd, Bellini LM, William of Occam and Occam's razor. Ann Intern Med. 2002 Apr 16;136(8):634-5.
• Kirk GW and Pemberton N. Leech, 2013
• Kirk GW and Pemberton N, Re-imagining Bleeders: The Medical Leech in the Nineteenth Century Bloodletting Encounter. Med Hist. 2011 Jul; 55(3): 355–360.
• La Berge A and Hannaway C, Paris Medicine: Perspective Past and Present.
• Louis PCA. Researches On The Effects Of Bloodletting In Some Inflammatory Diseases. Boston: Hilliard, Gray, 1836.
• Morabia A. PCA Louis and the birth of clinical epidemiology. J Clin Epidemiol 1996;49: 1327-33
• Morabia A, Pierre-Charles-Alexandre Louis and the evaluation of bloodletting. J R Soc Med. 2006 Mar; 99(3): 158–160.
• Niehyl PH. The English bloodletting revolution, or modem medicine before 1950. Bull Hist Med 1977; 51, pp. 464-483.
• Papavramidou N and Christopolou-Aletra H, Medicinal use of leeches in the texts of ancient Greek, Roman and early Byzantine writers. Intern Med J. 2009 Sep;39(9):624-7.
• "Suckers for Success," Nature volume 484, page 416 (26 April 2012).
• "Walter Chatton," Stanford Encyclopedia of Philosophy, retrieved from: https://plato.stanford.edu/entries/walter-chatton/
• Wardrop D, "Ockham's Razor: sharpen or re-sheathe?" J R Soc Med. 2008 Feb; 101(2): 50–51.