METHOD OF PERFORMING SUBCUTANEOUS INOCULATION 55 



necessary to shave the area. Apply a 2 per cent, iodin in alcohol solu- 

 tion. 



4. Pinch up a fold of skin between the forefinger and the thumb of 

 the left hand; hold the syringe in the right hand, and insert the needle 

 into the ridge of skin between the finger and thumb, and push it steadily 

 onward until the needle has been inserted about an inch (Fig. 27). 

 Care must be exercised not to enter the peritoneal cavity. Relax the 



FIG. 27. SUBCUTANEOUS INOCULATION OF A GUINEA-PIG. 

 A fold of skin is pinched up and the needle entered into the fold. The skin is 

 then released, and the injection slowly given. A swelling indicates that the injection 

 is subcutaneous. 



grasp of the left hand and slowly inject the fluid. If the skin is raised, 

 this shows that the injection is subcutaneous. If it is not, the needle 

 should be slightly withdrawn and inserted. 



5. Withdraw the needle, and at the same time cover the puncture 

 with a wad of cotton wet with alcohol. A touch of flexible collodion 

 over the puncture completes the operation. 



Solid Inoculum. Steps 1 to 3 are the same as in the preceding. 



