140 STRONG AND TEAGUE. 



the greater distances, they were exposed before cases which 

 did not cough, usually at a distance of from 5 to 18 centimeters 

 in front of the mouth and nose. Before coughing patients the 

 distances varied from 5 centimeters to 2 meters. A summary 

 of the details of the experiments follows. 



EXPERIMENTS. 

 SERIES I. 



On March 4, six plates containing agar were exposed in a ward containing 

 6 patients. Dimensions of ward about 3.5 by 4.5 meters. All plates exposed 

 before pneumonic-plague cases, none of which coughed during the time of 

 exposure. 



Plates A and B exposed for three minutes at a distance of 30 centi- 

 meters from the mouth of the patient. Result after forty-eight hours: 

 Both plates negative for colonies. 



Plates C and D exposed for one and one-half minutes at a distance 

 of 70 centimeters. Result after forty-eight hours: Both negative for 

 colonies. 



Plate E exposed for two minutes at a distance of 5 centimeters. Result 

 after forty-eight hours: Three colonies developed on the plate. Two of 

 these colonies are composed of a coarse bacillus which does not decolorize 

 by Gram. The third is composed of a coccus. 



Plate F exposed horizontally for eight minutes in the ward, 1 meter 

 from the nearest patient. After forty-eight hours 8 colonies developed. 

 On microscopical examination, none of the organisms composing these 

 colonies resembled the plague bacillus, either in cultural characteristics, 

 morphology, or in staining reactions. 



SERIES II. 



Case 1. — Pneumonic-plague patient; sputum not markedly blood-tinged, 

 but patient very ill. Plate containing agar exposed at a distance of 5 

 centimeters from the mouth for one minute. Respirations quiet. Result 

 after forty-eight hours: Two colonies have developed on the plate, one a 

 large white colony of a coarse bacillus which does not decolorize by Gram's 

 stain, the other a small and delicate colony planted on an agar slant. 

 This organism partially decolorizes by Gram's stain. Mice Nos. 4 and 6 

 inoculated subcutaneously with 0.5 oese of this organism. Neither of these 

 animals developed plague. 



Case 2. — Sputum slightly bloody; respirations quiet. Plate exposed at 

 a distance of 5 centimeters for one minute. Result after forty-eight 

 hours : Negative for colonies. 



Case 3. — Patient asleep. No coughing during exposure. Plate exposed 

 for two minutes at a distance of 5 centimeters from the mouth. Result 

 after forty-eight hours: Plate negative for colonies. 



Case U- — Patient very ill. Advanced case of plague pneumonia, with 

 much bloody sputum. Vapor arising from breath. Marked dyspnoea. 

 Groaned slightly while breathing. 



Plate A exposed at a distance of 5 centimeters for one minute. Result 

 after forty-eight hours: One colony, a pleomorphic bacillus, with square 

 ends. Evidently not plague. 



