Other entries in the Ding diary quoted below are typical of those made over a period of 3 years, and give some idea of the mortality among the victims. (_NO-265._) “_10 Jan 42: Preliminary test B_: Preliminary test to establish a sure means of infection: Much as in smallpox vaccination, 5 persons were infected with virus through 2 superficial and 2 deeper cuts in the upper arm. All of the humans used for this test fell ill with true typhus. Incubation period up to 6 days. “_20 Feb 42_: Chart of the case history of the preliminary tests to establish a sure means of infection were sent to Berlin. One death out of five sick. “_17 Mar 42_: Visit of Prof. Gildemeister and Prof. Rose (department head for tropical medicine of the Robert Koch Institute) at the experimental station. All persons experimented on fell sick with typhus, except two, who, the fact was established later, already had been sick with typhus during an epidemic at the police prison in Berlin. “_9 Jan 43_: By order of the surgeon general of the Waffen SS, SS Gruppenfuehrer and Major General of the Waffen SS, Dr. Genzken, the hitherto existing typhus research station at the concentration camp Buchenwald becomes the ‘Department for Typhus and Virus Research’. The head of the department will be SS Sturmbannfuehrer Dr. Ding. During his absence, the station medical officer of the Waffen SS, Weimar, SS Hauptsturmfuehrer Hoven will supervise the production of vaccines. “_13 and 14 Apr 43_: Unit of SS Sturmbannfeuhrer Dr. Ding ordered to I. G. Farbenindustrie A. G., Hoechst. Conference with Prof. Lautenschlaeger, Dr. Weber and Dr. Fussgaenger about the experimental series ‘Acridine Granulate and Rutenol’ in the concentration camp Buchenwald. Visit to Geheimrat Otto and Prof. Prigge in the institute for experimental therapeutics in Frankfurt-on-Main. “_24 Apr 1943_: Therapeutic experiments Acridine Granulate (A-GR2) and Rutenol (R-2) to carry out the therapeutic experiments Acridine Granulate and Rutenol, 30 persons (15 each) and 9 persons for control were infected by intravenous injection of 2 cc. each of fresh blood of a typhus sick person. All experimental persons got very serious typhus. “_1 Jun 1943_: Charts of case history completed. The experimental series was concluded with 21 deaths; of these, 8 were in Buchenwald, 8 with Rutenol and 5 control. “_7 Sep 1943_: Chart and case history completed. The experimental series was concluded with 53 deaths.