MICROSPIRA COMMA. 483 



with certainty the cholera organism by microscopic 

 examination. 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 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 access of oxy- 

 gen, there is present a body that possesses intensely 

 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 chloro- 

 form or thymol, and by drying, without apparently 

 any alteration of this poisonous body. Absolute alco- 

 hol, concentrated solutions of neutral salts, and a tem- 

 perature of 100 C., decompose this substance, leaving 

 intact secondary poisons which possess a similar physi- 

 ological activity, but only when given in from ten to 



1 Zeitschrift fur Hygiene uiid Infektionskrankheiteu, Bd. xi. S. 393. 



