14 THE BACTERIA IN ASIATIC CHOLERA. [CH. 



also contain other bacteria, e.g., the contents of a cholera- 

 intestine or cholera-dejecta, in contact with moist earth, or 

 by spreading them out on linen, and keeping them in a 

 damp condition. Comma-bacilli then increase visibly in 

 a very short time, and in an extraordinary manner in twenty- 

 four hours. Other bacteria that exist with them are at first 

 stifled by the comma-bacilli, a natural pure culture is 

 formed, and, on examining with the microscope the mass 

 that is taken from the surface of the damp earth or linen, 

 preparations can be obtained which show almost exclusively 

 comma-bacilli. 



"But this luxuriant growth of comma-bacilli does not 

 last long. After two or three days they begin to die off. 

 and other bacteria then increase. The conditions become 

 the same as in the intestine itself. There also a rapid 

 multiplication takes place ; but when the real vegetation- 

 period, which only lasts for a short time, is over, and 

 especially when exudations of blood into the intestine take 

 place, the comma-bacilli disappear, and the other bacteria, 

 especially putrefaction-bacteria, commence to develop in 

 their place. I am, therefore, almost inclined to believe 

 that, if the comma-bacilli were brought at first into a 

 putrefying liquid which contained a great deal of the pro- 

 ducts of vital changes of other bacteria, and especially of 

 putrefaction-bacteria, they would not come to development, 

 but would soon die off. But so far sufficient experiments 

 have not been made on this point ; it is only a supposition 

 which I make, supported by my experiences of other bacteria- 

 cultivations. This point is important, because it is not a 

 matter of indifference whether the comma-bacilli, if they 

 come into a sink or sewer, find a good or a very bad soil 

 for reproduction. In the first case, they would multiply, 

 and would have to be destroyed by methods of disinfection ; 



