62 



CONTROL SERIES No. 63 



with a biconvex film amounted to 0.02 cc. The blood and antigen were thor- 

 oughly mixed with the loop, and spread over an area approximately one-half 

 inch in diameter. The wire loop was rinsed in water and dried with gauze. The 

 time for reading was the same as for the slide-smear method. The temperature 

 of the glass plate was maintained at 22-35 ° C. This was accomplished through 

 the use of an improvised hot water heater. Keeping the testing plate at a tem- 

 perature above 22° C. appeared to produce more rapid and distinct reactions, 

 especially with bloods of low titered birds. The weather conditions were quite 

 favorable at the time of this test, even though the atmospheric temperature 

 was 15° F. Considerable dust which was present in the air settled on the tests 

 and the glass plate. The time consumed for the testing operations amounted to 

 approximately 43^ hours. The results of the second test were as follows: 



Whole Blood Tube 



Test Test 



Number of birds positive * 



Number of birds doubtful .'. 3 



Number of birds negative 221 224* 



* Includes one bird that escaped on the December 30 test, but tested negative on January 4. 



On January 25, the third test, 214 birds were tested by both methods. The 

 technique of the whole blood test was the same as that employed on December 

 30. The temperature in the poultry house was approximately 45 ° P\ The time 

 consumed for the testing operations amounted to 4 hours. The results of the 

 tests were as follows: 



Whole Blood Tube 



Test Test 



Number of birds positive 



Number of birds doubtful 6 1 



Number of birds negative 209 213 



