Experimental Production of Pneumococcus Pneumonia in Mice by the Inhalation Method

1. Non-immune mice which are alcoholized and die of septicemia following exposure to a spray of virulent pneumococci rarely show any localization of infection in the lung. 2. Mice which have been partially immunized by previous inhalations of living or killed pneumococci and which while alcoholized are exposed to an atmosphere of virulent pneumococci often develop a pneumococcus lobar pneumonia. 3. Mice which have been rendered relatively immune to one type of pneumococcus may frequently develop lobar pneumonia after the inhalation of pneumococci of another type.