Serum Diagnosis 559 



"agglutometers," in which are found such simple apparatus 

 and directions as will enable those inexpert in laboratory 

 manipulations to arrive at very accurate results. 



Serum Diagnosis. The specific action of the artificially 

 prepared serums can be used to differentiate cultures of 

 the colon, paracolon, typhoid, and paratyphoid bacilli, the 

 typhoid bacilli alone exhibiting the specific effect of the 

 typhoid serum. 



Richardson * has found it very convenient to saturate filter paper 

 with typhoid serum, dry it, cut into 0.5 cm. squares, and keep it on 

 hand in the laboratory for the purpose of making this differentiation. 

 To make a test, one of these little squares is dropped in 0.5 c.c. of a 

 twenty-four-hour-old bouillon culture of the suspected bacillus and 

 allowed to stand for five minutes. A drop of the fluid placed upon 

 a slide and covered will then show typical agglutinations if the culture 

 be one of the typhoid fever bacillus. In a second mention of this 

 method f he has found its use satisfactory in practice and the paper 

 serviceable after fourteen months' keeping. 



Christopher sif found that the serum from typhoid patients 

 occasionally caused agglutination of the colon bacillus, but 

 concludes that this does not lessen the specificity of the 

 reaction, as there may be two combined specific actions of 

 the serums. Experiments on rabbits have shown that both 

 typhoid and colon immune serums can be produced, each 

 specific in its agglutinating power upon cultures of its 

 respective organisms. 



iofifler and Abel also prepared a colon immune serum that 

 exerted a specific action upon the colon bacillus, but was 

 without effect upon the typhoid bacillus. 



An additional aid to the diagnosis of typhoid in doubtful 

 cases based upon the Wolff-Eisner-Calmette reaction in 

 tuberculosis is the "ocular typhoid reaction" of Chante- 

 messe. 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 eighteen- to- 

 twenty-hour-old culture of virulent typhoid bacilli were 

 washed with 4-5 c.c. of sterile water. The suspension thus 

 obtained was heated to 60 C., centrifugated, and the super- 

 natant fluid withdrawn. The centrifugated organisms were 

 then dried and triturated. A second suspension of these 



* "Centralbl. f. Bakt. u. Parasitenk.," 1897, p. 445. 



t "Journal of Experimental Medicine," May, 1898, p. 353, note. 



t "Brit. Med. Jour.," Jan. 8, 1898. 



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



