650 Typhoid Fever 



served that when blood-serum from typhoid fever patients 

 is added to cultures of the typhoid bacillus a definite reactive 

 phenomenon occurs. The phenomenon, now familiarly 

 known as the "Widal reaction," consists of complete loss 

 of the motion so characteristic of the typhoid bacillus, and 

 the collection of the micro-organisms into clusters or groups 

 agglutination. The bacteria frequently appear shrunken 

 and partly dissolved. 



The technic of the test is outlined in the section upon 

 Agglutination (q. v.). For the use of the practising physician, 

 commercial houses now furnish various outfits known as 

 "agglutometers," in which are found such simple apparatus 

 and directions as will enable those inexpert in laboratory 

 manipulations to arrive at very accurate results. 



The Blood-culture. The technic of this operation is sim- 

 ple. The skin of the fold of the elbow is thoroughly cleansed, 

 a fillet put about the arm, and as the veins become promi- 

 nent, a sterile hypodermic needle is introduced into one and 

 about 10 c.c. of blood drawn into the syringe. Before clot- 

 ting can take place, this is discharged into a small flask con- 

 taining loo c.c. of bouillon, mixed, and stood away to incu- 

 bate. After twenty-four hours the bacilli can usually be 

 found in pure culture. 



In case the culture is not pure, the typhoid bacillus can 

 be separated from contaminating organisms by plating. 



The Isolation of the Bacillus from the Feces. This 

 method of making the diagnosis has practically been aban- 

 doned because of its uncertainty, its cumber someness, its 

 tediousness, and because the preceding methods suffice in all 

 cases. 



An excellent resume of the many methods employed for 

 isolating the bacillus from the stools has been published by 

 Peabody and Pratt,* and is appropriate reading for those 

 interested in this subject. 



The Conjunctival Reaction. An additional aid to the di- 

 agnosis of typhoid in doubtful cases based upon the Wolff- 

 Eisner- Calmette reaction in tuberculosis is the "ocular ty- 

 phoid reaction" of Chantemesse. f This test consists in the 

 instillation into the eye of a solution made by extracting the 

 typhoid bacillus as follows: "Gelatin plates covered with an 



* "Boston Medical and Surgical Journal," 1907. 



t " Deutsche med. Wochenschrift," 1907, No. 31, p. 1264. 



