78 THE DISCOVERY OF CHICKEN CHOLERA, ETC. 



fluid ; the spleen was enlarged and dark in colour. The most 

 pronounced feature, however, was the enormous enlargement of 

 the liver, which was very dark in colour and extremely friable. 

 These appearances coincide exactly with those found in chicken 

 cholera. 



Cover-glass preparations of blood from the liver, stained 

 with Loftier 's alkaline methylene blue and examined under the 

 microscope with an oil immersion lens, were found to contain a 

 few bacteria morphologically identical with Pasteur's microbes 

 of chicken cholera. Inoculations were made with the blood of 

 the liver on a series of sterilised tubes of 15% nutrient gelatine, 

 2% of glycerine agar and peptonised beef broth. These cultiva- 

 tions were placed in the incubator at a temperature of 38° C. for 

 development ; in 24 hours a characteristic growth appeared in 

 each tube. The cultures were also examined microscopically, 

 with positive results. Several inoculations were made on steri- 

 lised potatoes, which yielded typical cultures in four days. 



Experiments on Rabbits, etc. 



Experiment 1. — A mere trace of the blood from the spleen 

 of the duck was injected into the subcutaneous tissue of a rabbit 

 and a mouse ; both died in about 14 hours, with all the symp- 

 toms peculiar to this disease. On microscopical examination of 

 the blood from various internal organs of both these animals, 

 the same bacteria were discovered ; cultures also yielded positive 

 results. 



Experiment 2. — Blood from rabbit 1 was injected into a 

 rabbit, a guinea-pig and a pigeon. In this experiment all the 

 animals died within 24 hours, of acute septicaemia. Microsco- 

 pical examination and cultivations on various nutrient media 

 gave positive results. 



Experiment 3. — A rabbit fed with a little of the blood from 

 rabbit 1 died in 20 hours, with the same characteristic symp- 

 toms. Microscopical examination and cultivations also gave 

 positive results. 



Experiment 4. — Four rabbits were fed with a broth culture 

 of the bacteria from the blood of rabbit 3 ; all died within 24 

 hours, with symptoms characteristic of infection from chicken 

 cholera. Microscopical examination and cultivations again gave 

 positive results. 



