A preliminary note upon experimental lobar pneumonia with a demonstration of specimens

Abstract

Soon after the relationship of the pneumococcus to lobar pneumonia was established, a great many attempts were made to produce lobar pneumonia in animals. As early as 1888 Gamaléia claimed to have succeeded in producing pneumonia regularly in sheep and dogs by injecting pneumococci directly into the lung through the chest wall; but he failed when he made the injections into the trachea. From then until 1903 the attempts of all investigators have been successful in producing a pneumonia in only a relatively small number of experiments, and the inflammation has been usually of the lobular type. Wadsworth in 1903 was able to produce pneumonia with regularity by intratracheal injection only in immunized rabbits.

Dogs were used in our experiments. Under anesthesia a small stomach tube (as used in the intra-tracheal method of artificial respiration by Meltzer and Auer) is introduced through the larnyx into a bronchus and from 5 to 10 c.c. of a broth culture of a very virulent pneumococcus injected through the tube. The animals quickly recover without untoward results. Until now fifteen animals have been so treated. Of these four are under observation; nine have been killed at various periods of time after the injection—from one to six days; and two have died.