ADMINISTRATION OF MEDICINES. 15 



3. Habit. — The effect of habit, in accustoming to the action of a 

 medicine, is well known. The influence of acrid or irritating sub- 

 stances is but little diminished by repetition. 



4. DUecbsed condition of the body. — This is well seen in the power 

 of the system to bear very large doses of opium in tetanus and 

 mania- a-potu, and of the different effects of calomel in different con- 

 ditions of the system. 



5. Temijerament and Idiosyncrasy will also modify the action 

 of medicines. These should always be ascertained in the adminis- 

 tration of our remedies. 



6. Tissue., or organ. — The stomach is much more susceptible 

 than the skin : carbonic acid, when inhaled into the lungs, acts as 

 a poison ; when swallowed into the stomach, it merely proves a 

 grateful stimulant. 



ADMINISTRATION OF MEDICINES. 



Under this head may be included the parts to which medicines are 

 applied, with the mode of their application, — and the forms in which 

 they are employed. 



The parts of the body to which medicines are most usually ap- 

 plied, are the stomach, rectum, skin, mucous membrane of the lungs, 

 and nostrils. 



The stomach is most frequently resorted to, both on account of 

 the facility of administration through it, its great susceptibility, and 

 its intimate relation with other parts. 



The rectu7n is employed, where the patient cannot swallow the 

 medicine, or where there is some objection for giving it by the 

 mouth, or when a local impression is desirable. Medicines thus 

 employed are called enemata^ or clysters, or injections. If intro- 

 duced in the solid state, they are named suppositories. The quan- 

 tity of the medicine, as a general rule, is three times that given by 

 the stomach. 



The skin is frequently made use of as a means of affecting the 

 system by remedies. These may be applied either cpidermically, or 

 endermically, — that is, to the sound skin, or to the skin deprived of 

 its cuticle. The endermic method is by far the most prompt and 

 powerful. The cuticle is best removed by means of a small blister: 

 and the proper parts for the application are the epigastrium, and the 

 insides of the limbs. The usual dose is three times the quantity 

 given by the mouth ; and the powdered substance should be properly 

 diluted, before being sprinkled upon the denuded surface. The cir- 

 cumstances which may demand the endermic method of administra- 

 tion are inability, or indisposition of the patient to swallow, or of the 

 stomach to retain the medicine ; inflammation of the gastric mucous 

 membrane, or a want of susceptibility of this part to the action of 

 the medicine, from frequent repetition ; the necessity, in urgent cases, 



