SPECIAL BACTERIOLOGY 
183 
shown in the famous epidemic of Hamburg (1892) where 
a terrible epidemic of the disease raged, while the town 
of Altona (as close to Hamburg as Brooklyn is to New 
York) which had a separate water supply, was scarcely 
touched. The prevention during an epidemic means a 
thorough filtration of water or the use of boiled water 
and the patient should be handled in the same manner 
as a typhoid case. 
The cholera spirillum produces an exotoxin and the 
infected animal elaborates bacteriolysins; it was in con¬ 
nection with the cholera spirillum that Pfeiffer has 
demonstrated bacteriolysins. One attack usually con¬ 
fers a permanent immunity. No successful immune treat¬ 
ment has as yet been developed. 
The Bacillus of Ducrey 
Bacillus of Ducrey is the organism which produces 
chancroid, an acute inflammatory lesion on the genital 
organs. It is acquired by direct contact. The bacillus 
is very small, nonmotile, has no flagella, no spores, no 
capsules. It is Gram-negative and grows on blood agar. 
