BACILLARY WHITE DIARRHEA IN YOUNG CHICKS. 7 



1 per cent, glycerine, 0.5 per cent, phenol). The resulting cloudy fluid 

 was then well shaken, .filtered through cotton, tested and preserved on 

 ice. In case any bottle of test fluid was not used immediately it was re- 

 tested before using it for diagnostic purposes. 



Methods of drawing and treating Blood Samples. 



In drawing blood samples from the birds tested we have found it con- 

 venient to make use of some sort of impro\dsed table upon which the birds 

 can be laid; and, at the same time, small collecting tubes, absorbent cotton 

 and carbolic acid can be arranged within easy reach. 



The hen is laid on her back on the table, with one wing projecting over 

 the edge; the feathers are quickly removed from a small area on the under- 

 side of the wing, so that the course of the wing vein may be seen clearly, 

 and the region washed with absorbent cotton wet with 2.5 per cent, car- 

 bolic acid. With scissors, or a sharp knife, a cut is then made in the vein 

 near the outer bend of the wing, wliich is slanted in such a way that the 

 blood flows directly into small sterile tubes. After a small amount (2 to 

 3 cubic centimeters) has been collected the cut is washed again with car- 

 bolic acid, and fresh, dry absorbent cotton is pressed against the wound 

 to check the flow of blood. With the cotton still under the wing the bird 

 is placed gently on the floor of the pen, and, in most cases, there is no 

 trouble with further bleeding. In the few instances where the blood has 

 not ceased flowing immediately additional pieces of absorbent cotton, 

 pressed over the incision and left under the wing, have been sufficien* to 

 stop bleeding. The tube in wliich the blood has been collected is then 

 plainly marked with the number of the hen from which it came, tightly 

 corked and set away to clot. 



After all samples are collected from the flock the tubes of blood are 

 taken to the laboratory and set on the ice until the clots are well formed. 

 They are then removed from the sides of the tubes and broken up by 

 means of sterile brass strips, one of which is in each collecting tube. After 

 remo\dng the brass strips it is customary to place the samples again on 

 ice over night. By morning the serum appears in appreciable quantities 

 above the clot, and, after centrifugahzing the contents of each tube, it 

 may be easily pipetted from the collecting tube into a sterile bottle in 

 which it is diluted ]-20 with sterile 0.85 per cent, salt solution, and kept 

 on ice until needed for further work. 



Making the Agglutination Test. 



For these tests small test tubes 100 millimeters long and 10 millimeters 

 cahber have been employed. In the majority of cases three tubes have 

 been used for each individual tested, two of the tubes containing 1.5 

 cubic centimeters test fluid and the third, 1.5 cubic centimeters carbo- 

 lated salt solution for a control. In tube No. 1 has been placed 0.3 cubic 

 centimeters diluted blood serum, making a final dilution of serum, 1-100; 



