very conclusively" that "miasms derived from the dissecting room will excite puerperal disease." One of the first to respond to Semmelweis's 1848 communications was James Young Simpson, who wrote a stinging letter. Simpson surmised that the British obstetrical literature must be totally unknown in Vienna, or Semmelweis would have known that the British had long regarded childbed fever as contagious and would have employed chlorine washing to protect against it. In 1856, Semmelweis's assistant Josef Fleischer reported the successful results of hand washing activities at St. Rochus and Pest maternity institutions in the Viennese Medical Weekly (Wiener Medizinische Wochenschrift). The editor remarked sarcastically that it was time people stopped being misled about the theory of chlorine washings. Two years later, Semmelweis published his own account of his work in an essay entitled "The Etiology of Childbed Fever". Two years after that, he published a second essay, "The Difference in Opinion between Myself and the English Physicians regarding Childbed Fever". In 1861, Semmelweis published his main work Die Ätiologie, der Begriff und die Prophylaxis des Kindbettfiebers (German for "The Etiology, Concept and Prophylaxis of Childbed Fever"). In his 1861 book, Semmelweis lamented the slow adoption of his ideas: "Most medical lecture halls continue to resound with lectures on epidemic childbed fever and with discourses against my theories. [...] In published medical works my teachings are either ignored or attacked. The medical faculty at Würzburg awarded a prize to a monograph written in 1859 in which my teachings were rejected". In a textbook, Carl Braun, Semmelweis's successor as assistant in the first clinic, identified 30 causes of childbed fever; only the 28th of these was cadaverous infection. Other supposed causes included conception and pregnancy, uremia, pressure exerted on adjacent organs by the shrinking uterus, emotional traumata, mistakes in diet, chilling, and atmospheric epidemic influences. Despite this opposition, Braun, who was Assistant in the First Division in the period April 1849 to summer 1853, maintained a relatively low mortality rate in the First Division, roughly consistent with the rate Semmelweis himself achieved, as mortality rates in the period April 1849 to end 1853 show. These results suggest that Braun continued, assiduously, to require the chlorine washings. At a conference of German physicians and natural scientists, most of the speakers rejected his doctrine, including the celebrated Rudolf Virchow, who was a scientist of the highest authority of his time. Virchow's great authority in medical