TRANSMISSION OF THE INFECTION. 143 



Case 3. — Much bloody sputum. Patient asleep during exposure and 

 groaning slightly. Plate exposed for two minutes at a distance of 5 

 centimeters. Result after forty-eight hours: Two large yellow colonies, 

 evidently not plague. On March 17, one red colony had also developed 

 on this plate, but no other colonies. 



Case U- — Advanced case with bloody sputum. Patient coughed several 

 times during exposure. Plate exposed for two minutes at a distance of 

 11 centimeters. Result after forty-eight hours: The whole surface of plate 

 covered with a thick layer of growth which has the odor of the Hay 

 bacillus. Plate discarded. 



Case 5. — Advanced case with bloody sputum. Patient snoring during 

 exposure. Plate exposed for two minutes at a distance of 11 centimeters 

 from the mouth. Result after forty-eight hours: 11 colonies; 3 resembling 

 colonies of the colon bacillus, the others are more delicate and might be 

 colonies of the plague bacillus. March 17, the majority of these colonies 

 are of bacilli which do not decolorize by Gram's stain. Three colonies are 

 found of a bacillus which does decolorize. These organisms were planted 

 on agar slants and later inoculated into guinea pigs Nos. 12, 5471, and 

 5472. All of these guinea pigs remained healthy. 



No. 6. — Plate exposed in plague ward for nine minutes about 1 meter 

 from the nearest patient. Result after forty-eight hours: The whole sur- 

 face covered with a whitish growth, beneath which are about 40 large 

 white colonies which do not resemble plague colonies. Plate discarded. 



No. 7. — Plate exposed in the ward, same as No. 6. Result after forty- 

 eight hours : Growth over entire surface of the plate. Impossible to study 

 individual colonies. Plate, therefore, discarded. 



SERIES V. 



Case 1. — Very sick, with much bloody sputum. In last stages of the 

 disease. Much dyspnoea and pulmonary oedema and much vapor arising 

 from the mouth. 



Plate A. Patient coughed once during exposure of plate which lasted 

 for one minute at a distance of 11 centimeters from the mouth. Result 

 after forty-eight hours: About 60 colonies are scattered over one-half of 

 the plate. Some of these look as though they might be plague colonies. 

 Three of these, the organisms comprising which decolorized by Gram's 

 stain and were bipolar when stained, were planted on agar slants and 

 later inoculated by the cutaneous method into guinea pigs Nos. 13, 5474, 

 and 5304, all of which died of typical plague infection. 



Plate B exposed for two minutes at a distance of 11 centimeters from 

 the mouth. Patient coughed slightly during the time of exposure. Result 

 after seventy-two hours: Thirteen colonies on the plate. Six, which were 

 large white colonies, could not be those of the plague bacillus. Seven of 

 them might be colonies of the plague bacillus. A number of these colonies 

 planted on agar slants as follows: 1 B l=:a short bacillus or coccus; 

 Gram-positive. 1 B 2 = a very fine coccus; Gram-positive. 1 B 3, no 

 growth. lB4 = a very small coccus. 1B5 and 1 B 6 = a bacillus which 

 decolorizes by Gram's stain; inoculated cutaneously into guinea pigs 

 Nos. 14 and 5309; both of these animals died of typical plague infection. 



Case 2. — Much bloody sputum, pulmonary oedema, and mai'ked dyspnoea. 

 Much visible vapor arising from the mouth. 



Plate A exposed for two minutes at a distance of 11 centimeters. 



