PEEPAEATION OF ANTI-HOG-CHOLEKA SERUM 91 



the ear vein. On this outlet tube is a pinch-cock 

 to control the flow of virus. The bottle is filled 

 with virus, the stopper is forced down tightly with 



PLATE 10. A close view showing the hypering process. 

 A 200 pound cholera immune hog receives 1000 mils 

 of virus in the ear vein. In ten days the animal is 

 ready to bleed for protective serum. New York State 

 Veterinary College at Cornell University 



