ANIMAL INOCULATIONS 45 



Rabbits, guinea-pigs, white mice, and white rats, are the 

 animals generally used. The first two may be injected 

 subcutaneously or intraperitoneally. The hair on the 

 abdomen, between the scapulae, or near the root of the 

 tail, whichever part be chosen for the injection, is clipped, 

 and the skin rubbed with cotton- wool soaked in 1 in 1,000 

 mercuric chloride solution. For a subcutaneous injection, 

 the skin is pinched up and the needle inserted. The 

 needle is run in for its whole length when a large amount 

 is to be injected. Intraperitoneal injections are made in 

 the lower part of the abdomen; the abdominal walls are 

 pinched up, and the needle passed through the fold and 

 then withdrawn until the point is felt to be free in the 

 abdominal cavity, when the contents of the syringe are 

 emptied. Care must be taken to avoid injuring the 

 intestines. A special curved needle, with the hole about a 

 quarter of its length from the point, is frequently used for 

 intraperitoneal injections. 



The large auricular veins of the ear render the rabbit a 

 suitable animal for intravenous injections. The vein 

 selected is rendered prominent by lightly pinching the 

 base of the ear. 



For a ' pocket inoculation ' a small incision is made in 

 the skin, and, the latter having been separated from the 

 muscles by inserting the point of a pair of scissors and 

 slightly opening them, the tissue is inserted in the cavity. 

 The wounds left after inoculation are closed with collodion, 

 collodion and wool, or with one or two sutures.' 



Mice are generally inoculated on the back, at the root of 

 the tail. Inoculations may also be made into the anterior 

 chamber of the eye, by rubbing infected material into a 

 scarified surface, or by the introduction of the material in 

 collodion sacs. 



Examination of the Dead Animal. As soon as pos- 

 sible the body is pinned on a board, the dorsal surface down. 

 The forceps, scissors, and scalpels, should be sterilised by 

 boiling in water containing a little sodium carbonate. The 

 animal and board are well soaked in disinfectant solution, 

 and the hair on the abdomen shaved or clipped. The 

 abdomen is seared with a hot iron, and an incision made 

 from the top of the sternum to the pubes; lateral incisions 

 are made, and the skin reflected and pinned out. 



A fresh set of instruments is used for the next 



