“…By 1900, Taylor 17 was able to review 34 cases of fatal Sulfonal intoxication, most of which showed significant degrees of "haematoporphyrinuria." These clinical observations led to experimentation with this drug in the rabbit and Stokvis, 8 Kast and Weiss, 18 Nakarei, 19 Neubauer, 20 and Perutz 21 detected "haematoporphyrinuria" within a few days of Sulfonal feeding. At necropsy, only the liver and bile consistently contained high porphyrin concentrations.…”