MODE OF ADMINISTRATION 7 



obstruction of horses. In such cases barium chloride and 

 eserine sulphate are employed intravenously. The jugu- 

 lar is occluded with the hand and the injection is made 

 with the same care described below in reference to the 

 subcutaneous method. The intravenous use of hot normal 

 salt solution is frequently valuable in hemorrhage, shock 

 and poisoning (see p. 733). 



2. Volatile drugs are absorbed with great rapidity and 

 effect owing to the enormous vascular surface of the lungs 

 in contact with the inhaled vapor. Ether, chloroform,, 

 ammonia and amyl-nitrite are given by this method. In- 

 halation of medicated steam and sprays, used mainly for 

 their local action on the respiratory tract, are also absorbed 

 to some extent by the bronchial mucous membrane and 

 lungs. This is a convenient and effective mode of applying 

 local medication to horses in inflammatory troubles of the 

 upper air passages, including the bronchial tubes, and in 

 many cases may effect a cure without the use of internal 

 remedies. 



3. Subcutaneous or hypodermatic injection is suitable 

 for soluble, non-irritating drugs of small bulk, when a sure 

 and rapid action is desired. The medicinal solution should 

 be free from solid particles and microorganisms. If the 

 solution is not clean, or is irritating, abscess may occur. 

 The syringe and needle must also be absolutely clean. 

 Solutions made by dropping tablets in pure drinking water 

 will rarely cause abscess, and the syringe may be made 

 aseptic by filling it with alcohol (70 per cent.) and wiping 

 the needle with the same, previous to their employment. 

 Solutions may be preserved for hypodermatic use with boric 

 acid (1 per cent.), but soluble tablets are more convenient. 



In practising this method the hair should be removed 

 from the seat of injection — preferably the thin skin under- 

 laid by connective tissue behind the elbow or on the abdo- 

 men — and the part washed ; then a loose fold of skin is 

 picked up and held firmly between the thumb and forefinger 

 of the left hand, while the needle is thrust under the skin, 



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