176 



G. G. Heslop: 



Agglutination. 



Macroscopic Method. 



For the purposes of an agglutination test a culture (second sub- 

 culture 20 days old) of the organism in Martin's broth plus 7S 

 per cent, ox serum was taken and tested with known positive 

 and negative sera, Nos. 8 and 7 respectively. The ingredients 

 were mixed in small agglutination tubes in the following pro- 

 portions, and placed in the incubator at 37°C. for 24 hours when 

 the result was read. 



Positive Serum, No. 8. 



Tube. Culture (undiluted). Serum (I in 1). 



Carbol* saline. 



Result. 







c.c. 





c.c. 





c.c. 



1 



- 





- 



1 



- 



1 



2 



- 





- 



075 



- 



1-25 



8 



- 





- 



05 



- 



1-5 



4 



- 





- 



025 



- 



175 



5 



- 





- 



01 



- 



19 



6 



- 





- 



006 



- 



1-94 



7 



- 





- 



0-04 



- 



196 



8 



- 





- 



— 



- 



2 



9 



- 



— 



- 



1 



- 



2 



10 



- 



1 



- 



— 



- 



— 









Negative Serum, 



No. 



7. 







c.c. 





c-c. 





c.c. 



1 



- 





- 



] 



- 



1 



2 



- 





- 



75 



- 



1-25 



3 



- 





- 



0-5 



- 



15 



4 



- 





* 



025 



- 



1-75 



5 



- 





- 



01 





1-9 



6 



- 





- 



0-06 



- 



194 



7 



- 





- 



004 



- 



196 



8 



- 





- 



— 



- 



2 



9 



- 



— 



- 



1 



- 



2 



10 



- 



1 





— 



- 



— ' 



No agglutination was perceptible in any tube of either series, 

 when the result was read after 24 hours' incubation at 37°C. The 

 tubes were allowed to stand at room temperature for a further 

 period of 16 hours, and were again examined, but no different 

 result was obtained at this second reading. 



In the conduct of these agglutination tests, those cultures were 

 selected which showed a maximum amount of opalescence. It 



* 05% carbolic acid in normal saline solution. 



