MODES OF ADMINISTERING DRUGS. 21 



(c) By the rectum, (or vagina in the female), in 

 the form of enema or injection (fluid), or of a supposi- 

 tory (solid). Sometimes drugs cannot be administered 

 by the mouth, either on account of some physical 

 obstacle, repugnance on the part of the patient, or 

 irritability of the stomach ; or to spare the strength 

 generally, and the stomach especially, in conditions of 

 exhaustion. Again, the action desired may be a local 

 one on the rectum and pelvic organs, e.g. to relieve 

 pain, destroy worms, or soften retained faeces. 



(d) By injection under the skin subcutaneous 

 or hypodermic injection, or into the tissues inter- 

 stitial injection : excellent methods of admitting some 

 remedies into the system with certainty and despatch, 

 and in small bulk. 



(e) By application to wounds or diseased sur- 

 faces, as lotions, poultices, gargles, injections, colly ria ; 

 or by the endermic method, i.e. by being sprinkled on 

 a blistered surface. 



(/) By inhalation, the substances being some- 

 times volatile, and intended either to enter the blood 

 through the pulmonary capillaries, e.g. chloroform, or 

 to act directly on the parts to which they gain access in 

 the form of smoke, e.g. cigarettes, powders, etc. ; some- 

 times medicated watery vapours, such as Vapor Conii. 



(g) By intravenous injection, very rarely practised 

 in man. 



3. The Dose. The Pharmacopoeia indicates the 

 limits of ordinary doses, the minimum being the 

 smallest useful dose which it may be wise to begin 

 with, and the maximum being the largest usually 

 given without special reason and caution. Experience 

 alone can teach the practitioner how far he may 

 safely and wisely depart from these limits, to which 

 he is in no wise tied by law. Several modifying 

 circumstances which are to be taken into account 

 with respect to doses must here be carefully noted, 



