2 BULLETIN 5i: 
taminated incubators or brooders could be controlled readil}^ by sani- 
tary measures, but infection through the egg must be prevented by 
a process of weeding out the carriers among the hens used for 
breeding. 
THE AGGLUTINATION TEST. 
Since the presence of the Bacterium jpuUoruim in the ovarj^ of the 
hen is not betrayed by external symptom±s, it was necessar}^ to devise 
a biologic method of diagnosis in order to detect the presence of the 
disease in the affected birds. The agglutination test was found to 
be applicable for this purpose, and several agricultural experiment 
stations have taken up the work on an extended scale, offering the 
service to poultrymen at a price that barely covers the cost of the 
work. This, in Connecticut, is understood to be 10 cents a fowl. 
The work of drawing blood samples and sending to a laboratory is 
necessarily tedious and relatively expensive as compared with the 
value of a bird. A simpler, cheaper, and equally accurate diag- 
nostic method Avould undoubtedly contribute to greater popularity 
of this valuable work in disease prevention. 
EXPERIMENTAL WORK. 
The writers have undertaken to determine the possibilit}^ of pre- 
paring a biological product from Bacterium pullorum. to be used for 
the diagnosis of the disease caused by that organism. The general 
idea was to develop a diagnostic method somewhat analogous to the 
intradermal tuberculin test, particularly as applied to fowls. 
TEST OF ARTIFICIALLY INFECTED BIRDS. 
Two strains of Bacterium fullorum.' were planted in 1,500 c. c. of 
plain bouillon in the amount of one loopful each. This culture was 
incubated at 37° C. from September 19 to October 19, 1914. It was 
then placed in the ice box until May 4, 1915. On this date 100 c. c. 
of the culture was passed through a Berkefeld filter. The filtrate 
was determined to be sterile b}^ cultural tests. Carbolic acid was 
then added in sufficient quantit}^ to make a 0.5 per cent solution. 
On May IT, 1915, two drops of this filtrate were injected into the 
right wattle of a hen that had been injected with Bacterium pullorum 
on September 22, 1914. The liquid was injected slightly above the 
lovv^er border of the wattle and no attempt was made to place it 
within the layers of skin. Twenty-four hours later the Avattle showed 
an edematous swelling. 'The following day, 48 hours after injection, 
there was noted a pronounced edematous infiltration of the entire 
Avattle. A swelling of this size in other intradermal tests would be 
considered as positive. The temperature was normal. On May 20 
the swelling of the Avattle decreased crnsiderably. and 90 hours after 
