310 



AGGLUTININS 



mal salt solution receives a similar amount of bacteria, and serves as the 

 typhoid control. 



3. In each tube of the third and fourth rows five loopfuls of para- 

 typhoid bacilli are emulsified. Arrange the paratyphoid culture control. 



4. Mix gently and incubate for four hours. Carefully record the 

 presence or absence of agglutination in each test-tube. Centrifuge all 

 the tubes excepting the two controls, and transfer the supernatant fluid 

 of each to other test-tubes arranged in the same order. 



5. To each tube of the first and third rows add five loopfuls of ty- 

 phoid bacilli; to each of the second and fourth rows, five loopfuls of 

 paratyphoid bacilli. Mix well and incubate for four hours. 



(a) If typhoid is present, the agglutination titer in the first part of 

 the test will be strong in the tubes of the first and second rows, and weak 

 in those of the second and third rows. In the second part of the test the 

 titer for typhoid will be weak or nil in the first, second, and fourth rows, 

 whereas in the third row it will remain practically the same. 



(6) If paratyphoid exists, the agglutination titer in the first part of 

 the test will be strong in the tubes of the third and fourth rows, and weak 

 in those of the first and second rows. In the second part of the test the 

 titer for paratyphoid will be less or nil in the fourth row, and strong or 

 unchanged in the second row. 



(c) If a mixed infection exists, the agglutination titer in the first part 

 of the test will be strong in the tubes of all four rows. In the second 

 part of the test the titer in the first and fourth rows is much weaker or 

 nil, and in the second and third rows it will remain the same. 



Technic of Acid Agglutination. Mixtures of lactic acid and sodium 

 lactate have been general^ employed. Gillespie has prepared these from 

 stock solutions of one-third normal sodium lactate, with a small crystal 

 of thymol, and normal lactic acid, according to the following scheme: 



A series of greater dilutions of lactates may be made by diluting 

 each of the above with one or more volumes of distilled water. 



1 Read 0.12 c.c. of normal acid freshly diluted 1 : 8. 



