METHOD OF MAKING INTRAVENOUS INOCULATION 57 



7. The inoculum should be free from solid particles, and all the air 

 excluded from the syringe. As a general rule, the amount injected 

 should be as small as possible, and the. temperature of the inoculum be 

 near that of the body. If the syringe is filled shortly after sterilization, 

 when it has cooled enough to be comfortably hot to the touch the heat 

 will warm the injection fluid and not be hot enough to cause coagulation. 



8. Hold the syringe as one would hold a pen, and thrust the point 

 of the needle through the skin and the wall of the vein until it enters the 

 lumen of the vein (Fig. 28). 



9. Direct the assistant to release the pressure at the root of the ear, 

 and slowly inject the inoculum. If the fluid is being forced into the 



FIG. 28. INTRAVENOUS INOCULATION OF A RABBIT. 



subcutaneous tissue, which will be evident at once by the swelling which 

 occurs, the injection must cease and another attempt be made. 



10. The needle is quickly withdrawn, a small piece of cotton moist- 

 ened with alcohol placed upon the puncture wound, and firm compression 

 applied. Wash the ear thoroughly with alcohol and water to remove xylol, 

 otherwise a low-grade inflammation which will render subsequent injec- 

 tions more difficult will follow. 



Guinea-pig. 1. Since the superficial veins are quite small, it is 

 necessary to make the injection into the external jugular vein. 



2. The animal is tied to the operating-table and the hair clipped 

 away about the neck and shoulder on the right side, and 2 per cent, 

 iodin in alcohol applied. 



