The individuals admitted to this hospital were obtained from the two military camps at the University of Pittsburgh and the Carnegie School of Technology. All of them were enrolled in the army service and ranged from the ages of 18 to 30. They were vigorous individuals, who had passed their physical examinations for the army. The epidemic made its appearance in these camps on October 2, rapidly ascending from a report of two ill on October 2, four on October 3, eight on October 4, to 65 on October 5. On October 11 there were 307 cases in the hospital. Of these cases 35 died, the day of death being indicated in the following table. TABLE II ═══════════════════════════════════════════════╤═══════════════════════ DAY OF DISEASE ON WHICH DEATH OCCURRED │ NUMBER OF CASES ───────────────────────────────────────────────┼─────────────────────── Third │ 1 Fourth │ 3 Fifth │ 4 Sixth │ 4 Seventh │ 4 Eighth │ 5 Ninth │ 3 Tenth │ 4 Eleventh │ 3 Thirteenth │ 1 Fourteenth │ 1 Twentieth │ 1 Twenty-third │ 1 ───────────────────────────────────────────────┴─────────────────────── The time as indicated in the above table has no relation to the length of time that the patients were ill of pneumonia, but refer to the period of illness from the beginning of the influenza. The duration of the pneumonia is indicated in another table. Of the 35 fatal cases 32 came to autopsy. Facilities were available to do the work very satisfactorily, in that the hospital was well provided with a modern post-mortem room and its accessories. The notes on the autopsies were taken immediately and fully, and the materials for subsequent study were collected in different types of preserving fluid. Portions of tissue were collected from all of the organs for microscopical study, while fluids from the chest, lungs, bronchi and heart were obtained for bacteriological investigations and for some chemical analyses.