62 BACTERIOLOGY FOR NURSES 



The method of inoculation may be 



(1) Cutaneous. The hair is removed by shaving from a small 



area of the abdomen or back and the skin thoroughly 

 cleansed. A few parallel scratches are made just deep 

 enough to draw blood and the infective material rubbed 

 in with a sterile spatula or platinum loop. 



(2) Intracutaneous. The hair is cut or shaved from the part 



to be inoculated and the skin thoroughly cleansed. A 

 little of the skin is pinched up between the thumb and 

 forefinger of the left hand, the needle inserted in a slant- 

 ing direction, and the inoculation made. The puncture 

 may be sealed with collodion or painted with iodine. 



(3) Subcutaneous. The procedure is the same as (2) save 



that the hypodermic needle penetrates beneath the skin. 

 When mice or rats are injected by this method, the 

 inoculation is usually made near the base of the tail. 



(4) Intraperitoneal. The hair is cut over the lower part of 



the abdomen and the skin cleansed. The entire thick- 

 ness of the abdominal wall is pinched up between the 

 thumb and forefinger of the left hand, the hypodermic 

 needle inserted and gently moved about to be sure that 

 the intestine has not been perforated, and the injection 

 made. On withdrawing the needle the puncture point 

 is painted with iodine. 



(5) Intravenous. The larger animals are usually employed 



for this method. If a rabbit is to be inoculated a vein 

 on the outer margin of the ear is chosen, the hair clipped, 

 the skin cleansed, and the animal is held head downwards 

 for a few seconds so that the head may fill with blood 

 and the vein become distended. The hypodermic needle 

 is held almost parallel to the ear and then inserted into the 

 vein. If when the fluid is injected a slight increase in 

 the lumen of the vein is noted it will be evident that 

 the injection has been made into the vein ; if on the other 

 hand a small round swelling occurs the fluid is in the 

 surrounding tissue and has not entered the vein. 



