CHOLERA 173 



CHAPTER XV 



CHOLERA 



Experiine7its. 



Maddox (1885) was the first to carry out experiments on the 

 relation of flies to cholera by feeding C. voniitoria and E. teiiax 

 with cultures. He states that he found these organisms in their 

 faeces, but his methods were not very satisfactory. Sawtchenko 

 (1892) fed flies on broth cultures and found the vibrios in their 

 faeces two hours later. He also found the vibrios in the flies' 

 intestines and gained the impression that they multiplied in 

 their bodies. Simmonds (1892) placed flies on opened intestines 

 of persons who had died of cholera, and then transferred them 

 singly to large flasks in which they could fly and move about 

 freely. Roll cultures of these flies made at intervals from five 

 to ninety minutes all gave positive results. Uffelman (1892) 

 allowed two flies to feed on liquid gelatin cultures of V. cliolcrce, 

 and after keeping them separately for an hour and two hours 

 respectively, made cultures from them.. The first yielded 10,000, 

 and the second 25 colonies. He also demonstrated that flies 

 infected in this way could contaminate milk on which they fed. 

 Tsuzuki (1904, p. 77) showed that infected flies could contaminate 

 media over which they walked, and Chantemesse (1905) and 

 Ganon (1908) isolated the vibrios from flies 17 and 24 hours 

 respectively after infection. Graham-Smith (1910, p. 35) experi- 

 menting with old laboratory cultures found that the vibrios soon 

 died on the legs and wings, and that even in the crop and 

 intestine their numbers rapidly diminished, all cultures made 

 more than 48 hours after infection yielding negative results. 

 Infected faeces were passed for 30 hours. 



Isolation of V. cJiolercB from ' ivild ' flies. 



Simmonds (1892) isolated the vibrios from a fly caught in 

 the post-mortem room of the Old General Hospital in Hamburg, 



