ADMINISTRATION OF MEDICINES. 13 



temperature of the whole body. High fever and heat strokes are 

 treated in this way. 



By the tissue beneath the skin. — Hypodermic or subcutaneous 

 injections are often made for the purpose of introducing a drug, 

 reagent, or vaccine directly into the connecting tissue beneath the 

 skin. Introduced in this way, the substance is quickly absorbed, 

 none of it is lost, and its whole effect is obtained, often within a few 

 minutes. 



There are numerous precautions necessary in making a subcutane- 

 ous injection, most of which have to do with cleansing and steriliza- 

 tion. It is also important to select a proper site for the injection, so 

 that blood vessels, joints, and superficial nerves, organs, or cavities 

 may all be avoided. With due regard for the necessary precautions, 

 there is practically no danger in such an injection, but it should be 

 attempted only by those who are able to carry it through in a surgi- 

 cally clean way. Only certain drugs can be given subcutaneously, 

 and dosage must be accurately gi-aduated. 



By the VEINS. — Certain medicines act most promptly and surely 

 when introduced directly into the blood by injecting them into a vein. 

 The jugular vein is usually selected for this purpose. Some vaccines 

 and antitoxins are administered in this way. Intravenous injection 

 should be practiced only by experienced veterinarians. 



