340 BACTERIOLOGY. 



lowing method devised by him for the bacteriological 

 examination of dejections from cholera patients : 



In dejections that are not examined immediately after 

 being passed it is often difficult, because of the large 

 number of other bacteria that may be present, to detect 

 with certainty the cholera organism by microscopic ex- 

 amination. It is advantageous in these cases to mix the 

 dejections with about double their volume of slightly 

 alkaline beef tea, and allow them to stand for about 

 twelve hours at a temperature of between 30 and 40 C. 

 There appears at the end of this time, especially upon 

 the surface of the fluid, a conspicuous increase in the 

 number of comma bacilli, and cover-slip preparations 

 made from the upper layers of the fluid will reveal an 

 almost pure culture of this organism. 



It is not improbable that a similar process occurs in 

 the intestines of those suffering from Asiatic cholera, 

 viz., a rapid multiplication of the comma bacilli that 

 have gained access to the intestines takes place, but lasts 

 for only a short time, when the comma bacilli begin to 

 disappear, and after a few days their place is taken by 

 other organisms. 



In connection with his experiments upon the poison 

 produced by the cholera organism, Pfeiffer 1 states that 

 in very young cultures, grown under the access of oxy- 

 gen, there is present a poisonous body that possesses 

 intense toxic properties. This primary cholera- poison 

 stands in very close relation to the material composing 

 the bodies of the bacteria themselves, and is probably an 

 integral constituent of them, for the vitality of the cholera 

 spirilla can be destroyed by means of chloroform and 



1 Zeitschrift f. Hygiene u. Infectionskrankheiten, Bd. xi., p. 393. 



