86 HOG CHOLERA 



in antiseptic solution, leaving only the throat ex- 

 posed, and all is ready to draw the blood. 



An ordinary two-quart fruit jar, previously 

 sterilized, is a good receptacle. The sticking may 

 be done with a large cannula designed especially 

 for the purpose, or with a narrow bladed knife. 

 In case a knife is used the hand should be held 

 low on the throat so that the blade passes directly 

 upward, the back against the dorsal surface of the 

 sternum. The blade should not leave the median 

 line, but should be forced upward until it severs a 

 carotid or the anterior aorta near the bifurcation. 

 A free clean incision made in withdrawing the 

 knife facilitates rapid and complete bleeding. A 

 pig weighing one hundred pounds should yield 

 about one thousand mils of blood. If pigs are 

 killed too late, after they are very weak, the yield 

 is greatly reduced. 



Handling the virus blood. Immediately after 

 the blood is drawn it is defibrinated. This is done 

 by closing the receptacle tightly and shaking it 

 vigorously for a few moments. It is then marked 

 for identification and placed in ice- water pending 

 the time when the pig that yielded the blood can 

 be autopsied. Assuming that the autopsy, which 

 will be considered later, has been satisfactory, the 

 next step is to separate out the fluid part of the 

 blood, leaving the clot and fibrin behind. This is 

 accomplished in various ways. Some use a cen- 



