490 



STATP] BOARD OF AGRICULTURE. 



introduced into tlie filtrate whicli was again incubated at the above 

 temperature. 



The number of typhoid bacilli introduced into each cc. of the filtrate 

 was determined as follows : A small portion of an 18-24 hour broth 

 culture of B. typliosns was introduced into the filtrate by means of a 

 sterile i)ipette. Three agar plates were then made, using 1 cc, 0.5 cc. 

 and 0.1 cc, respectively of the inoculated filtrate, and the average count 

 taken after a sulHcieut period of incubation. After 24 hours a second 

 set of plates was made using the same dilutions as before. If the 

 filtrate had become turbid, dilutions of 1-1,000,000', 1-5,000,000 and 1-10,- 

 000,000 were used for plating. 



If the second ])latiug showed the presence of typhoid bacteria in the 

 filtrate, a third set of plates was made, etc. 



TABLE Yl.— Street, lacticus. 



