LOCAL AND GENERAL ACTIONS 711 



cent, solution of sodium chloride. Drugs injected into the 

 peritoneal and other serous cavities are very rapidly ab- 

 sorbed. They are also quickly taken up from abraded skin 

 surfaces. 



The channels by which medicines may be administered 

 are : 



1. The digestive tract, generally by the mouth (bolus, pill, 

 drench, electuary), and occasionally by the rectum (evacuant, 

 nutrient, anodyne, or anaesthetic enemata). 



2. The pulmonary mucous membrane, by inhalation 

 (anaesthetics, fumigations). 



3. Intratracheal injection. 



4. Intravenous injection. 



5. Intraperitoneal injection. 



6. The skin : (a) epidermically by inrubbing ; (b) 

 endermically by inunction after removal of the epidermis. 



7. Hypodermically, by injection into the subcutaneous 

 connective tissues. Intramuscular, intramammary, intra- 

 spinal, intrauterine, and subconjunctival injections are also 

 employed, and occasionally injections are made into the 

 nasal chambers, urethra, bladder, and vagina. Medicated 

 spray thrown from an atomizer, or from a steam spray 

 producer, is used for irrigating the throat, when irritable or 

 relaxed, especially in horses. 



The mouth is the channel by which medicines are most 

 frequently administered, for they immediately pass into the 

 stomach or intestine, whence they are readily and rapidly 

 absorbed. To avoid their admixture with food, and conse- 

 quent impaired and delayed effect, they should generally be 

 given after the patient has been fasted for several hours. 

 Nutrient oils, iron salts, arsenic, and other irritants are, 

 however, given with the food, or immediately after eating. 

 When it is desired that they shall be quickly absorbed, 

 and thus act promptly and certainly, they should be given 

 in the fluid state, and this is especially requisite in rumi- 

 nants. The time, labour, and patience of attendants may 

 be saved, and high-spirited, nervous animals preserved from 

 injurious struggling, if they can be persuaded to take their 

 medicines voluntarily. This may sometimes be accom- 

 plished when comparatively concentrated, tasteless, or 



