TYPHOID FEVER. 489 



The occasional persistence of the reaction for some 

 years may lead to errors of diagnosis, but is not apt to 

 do so if the previous history of the case can be properly 

 studied. 



It is said that the reaction sometimes disappears shortly 

 before death. 



III. The Distribution of the Agglutinating Substance. 

 — Being a substance dissolved in the blood, the aggluti- 

 nating substance is present in the various secretions ex- 

 tracted from it. 



In Widal's paper, reviewing the whole subject, 1 he 

 says the agglutinating substance has been found in the 

 blood, urine, the serous fluid from blisters, the pleural 

 pericardial, and peritoneal fluids, milk, bile, seminal 

 fluid, aqueous humor, tears, pleural exudates, and to a 

 less extent in the spleen, liver, and mesenteric glands. 



Catrin 2 found it in the pus of a phlegmonous inflam- 

 mation occurring during typhoid fever, and Block asserts 

 that it is present in the typhoid stools. 



Thiercelin 3 found it absent from the spontaneous sweat 

 when present in the blood and milk. 



In a case with two relapses whose blood was strongly 

 agglutinative I failed to find any agglutinative principle 

 in the urine. 



The fact that the typhoid bacilli are found scattered 

 through the body in little groups would suggest that 

 agglutination took place in the circulating blood of the 

 infected individual. Salimbeni, however, asserts that 

 such agglutinations do not occur. 



IV. The relation zvhich the reaction bears to the germi- 

 cidal activity of the blood has been pretty carefully studied, 

 but nothing definite established. In general it is found 

 that the fresher the blood, the more readily bacteriolysis 

 is observed. Johnston and McTaggart 4 state that " with 



1 Ann. de f Inst. Pasteur, May, 1897, No. 5. 



J Gas. de Med. de Paris, Oct. 15, 1896. 



3 Compt. rendu de la Soc. de Biol., Dec. 19, 1896, No. 33. 



* Montreal Med. Journ., Mar., 1897. 



