DIAGNOSIS OF INFECTION WITH B. PULLORUM. 13 



The finger of the operator was placed under the vena ulnaris, between the 

 uhial and radial bones near the distal ends, and pressed until the vein by 

 distention shows plainly. Then having sterilized the part, and using 

 sterile fine scissors, a cut was made through the cutaneous tissue into the 

 vein, making a short cut longitudinally. The blood will flow out in large 

 drops, and can be easily collected into a test tube, and by using a pledget 

 of cotton moistened with 1-40 carbolic acid the flow of blood can be quickly 

 stopped, and then bj^ placing a dry piece of cotton over the incision and 

 closing the wing down tightly, in a few minutes the individual may be 

 returned to the pen. Blood thus obtained is allowed to clot, and the serum 

 is later drawn off as a straw-colored supernatant fluid. This is then diluted 

 with carbolated salt solution to the usual stock dilution 1-20. 



Making the Agglutination Test. 

 Small test tubes 4 inches long and ^-inch calibre were used. During 

 some of our preliminary tests 3 c.c. test fluid was used as suggested by 

 Jones, ^ but it was found after several sets had been tried out that 1.5 c.c. 

 of the test fluid gave equally good results. The dilutions used most were 

 1-100, 1-200 and 1-500, but in some of the work test dilutions from 1-100 

 to 1-5,000 were used and made as follows : all sera were diluted 1-20, and 

 then by a simple algebraic calculation the amount of diluted (1-20) serum 

 necessary to add to 1.5 c.c. test fluid to make a desired dilution was de- 

 termined. For example, 1.5 c.c. test fluid -f .3 c.c. (1-20 serum) = 

 dilution 1-100 desired. The following amounts of diluted 1-20 serum 

 were added to 1.5 c.c. test fluid to make required dilutions: — 



1- 100= .3 c.c. diluted serum 1-20. 

 1- 200= . 15 c.c. diluted serum 1-20. 

 1- 300= .099 c.c. diluted serum 1-20. 

 1- 400= .075 c.c. diluted serum 1-20. 

 1- 500= .06 c.c. diluted serum 1-20. 

 1- 800= .037 c.c. diluted serum 1-20. 

 1-1,000= .03 c.c. diluted serum 1-20. 

 1-1,200= .025 c.c. diluted serum 1-20. 

 1-1,500= .019 c.c. diluted serum 1-20. 

 1-1,800= .016 c.c. diluted serum 1-20. 

 1-2,000= .015 c.c. diluted serum 1-20. 

 1-2,500= .012 c.c. diluted serum 1-20. 

 1-3,000= .009 c.c. diluted serum 1-20. 

 1-4,000= .007 c.c. diluted serum 1-20. 

 1-5,000= .006 c.c. diluted serum 1-20. 



Three sets of graduated pipettes were used, the first, a 5 c.c. graduated 

 to To c.c. ; the second, graduated to tJt) c.c. The pipette graduated to tou 

 c.c. was used to make dilutions up to 1-500, and for dilutions 1-500 to 

 1-5,000 one divided into toVo of c.c. was employed. After having made 



' Jones, F. S.: " The value of the macroscopic agglutination test in detecting fowls that are 

 harboring Bad. pullorum." Journal Medical Research, Vol. XXVII., No. 4; N. S., Vol. XXII., 

 No. 4, pp. 485-495. 



