INTRAPERITONEAL INJECTION. 113 



for inoculation is either near the root of the tail, or between 

 the scapulae, the advantage being that the animal cannot 

 suck the point of inoculation in such situations. The hair 

 is cut off the part, and the skin purified with i to 1000 cor- 

 rosive sublimate. The skin is then pinched up, and the 

 needle being inserted the requisite dose is administered. 

 The wound is then sealed with a little collodion. 



3. Intraperitoneal Injection. This is best performed by 

 means of a special form of needle. The needle is curved, and 

 has its opening not at the point, but in the 



side in the middle of the arch (Fig. 38). 

 The hair over the lower part of the abdomen 

 is cut, and the skin purified with an anti- 

 septic. The whole thickness of the ab- 

 dominal walls is then pinched up by an 

 assistant, between the forefingers and thumbs 

 of the two hands. The needle is then 

 plunged through the fold thus formed. The 

 result is that the hole in the side of the needle 

 is within the abdominal cavity, and the in- 

 oculation can thus be made. Intraperitoneal FIG. 38. Hoi- 

 inoculation can also be practised with an J^^^^ 

 ordinary needle. The mode of procedure is ( at a ) for intra- 

 similar, but after the needle is plunged through peritoneal inocu- 

 the abdominal fold, it is partially withdrawn 1: 

 till the point is felt to be free in the peritoneal cavity when 

 the injection is made. There is little risk of injuring the 

 intestines by either method. 



4. Intravenous Injection. The vein most usually chosen 

 is one of the auricular veins. The part has the hair removed, 

 the skin is purified, and the vein made prominent by 

 pressing on it between the point of inoculation and the 

 heart. The needle is then plunged into the vein and the 

 fluid injected. That it has perforated the vessel will be 

 shown by the escape of a little blood ; and that the injec- 

 tion has taken place into the lumen of the vessel will be 

 known by the absence of the small swelling which occurs in 

 subcutaneous injections. If preferred, the vein may be first 



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