616 Asiatic Cholera 



live: The organism should liquefy 10 per cent, gelatin and 

 should not coagulate milk. (4) Metabolic: Indol reaction 

 should be marked. (5) Immunity reactions: The organism 

 when injected into guinea-pigs in ascending doses should 

 occasion immunity against the typical cholera organism, 

 and the serum of the immunized guinea-pig, when intro- 

 duced into a new guinea-pig, should protect it from infection 

 and produce Pfeiffer's phenomenon. The blood-serum of 

 animals immunized against the cholera organism should 

 agglutinate the doubtful organism in approximately the 

 same dilution, and that of animals immunized to the doubtful 

 organism should agglutinate the cholera organism recipro- 

 cally. Both organisms should have equal capacity for 

 absorbing complements and amboceptors from blood-serum. 

 (6) The true cholera organism should not be hemolytic. 

 Too much reliance must not be placed upon the agglu- 

 tination tests alone, as will be made clear by a perusal of 

 the paper upon Bacteriological Diagnosis of Cholera by 

 Ruffer.* 



Immunity. One attack of cholera usually leaves the vic- 

 tim immune from further attacks of the disease. Gruber 

 and Wiener,! Haffkine, } Pawlowsky, and Pfeiffer|| have im- 

 munized animals against toxic substances from cholera cul- 

 tures or against living cultures. 



Pfeiffer and Vogedes** have applied the "immunity re- 

 action" to the differentiation of cholera spirilla in cultures. 

 A hanging drop of a i : 50 mixture of a powerful anticholera 

 serum and a particle of cholera culture is made and ex- 

 amined under the microscope. The cholera spirilla at once 

 become inactive, and are in a short time converted into 

 little rolled-up masses. If the culture added be a spirillum 

 other than the true cholera spirillum, instead of being 

 destroyed the micro-organisms multiply and thrive in the 

 mixture of serum and bouillon. 



Sobernheimft found the Pfeiffer reaction specific against 



* "British Medical Journal," March 30, 1907, i, p. 735. 

 t "Centralbl. f. Bakt.," etc., 1892, xiv, p. 76. 



J"L,e Bull, med.," 1892, p. 1113, and "Brit. Med. Jour.," 1893, 

 p. 278. 



"Deutsche med. Wochenschrift," 1893, No. 22. 

 || "Zeitschrift fur Hygiene," Bd. xvm and xx. 



** "Centralbl. f. Bakt. u. Parasitenk.," March 21, 1896, Bd. xix, 

 No. 1 1 . 



t| "Zeitschrift fur Hygiene," xx, p. 438. 



