414 ANDROPHYSICS. 



tion, by relaxing the nerves which produce it. Astringents, are 

 sometimes used internally as tonics, to give strength ; but more fre- 

 quently as styptics, to contract the muscular fiibres, and arrest the 

 effusion of blood. 



The sedative medicines, include sedatives proper, which, acting 

 on the nerves, or on the vascular system, diminish vital action ; also 

 narcotics, which first excite and then diminish nervous action, pro- 

 ducing, in sufficient doses, lethargy or stupefaction ; also refrigerants, 

 which reduce morbid heat, or heat caused by disease ; and finally 

 naitseants, which by producing nausea, flow of saliva, and perspira- 

 tion, allay morbid action. The Chemical agents, are antacids, used 

 to counteract acidity, particularly in the stomach ; ant alkalies, used 

 to counteract alkalinity ; antilithics, designed to prevent, and lit/ton- 

 tripfics, to remove, urinary calculus, or stone in the bladder ; and 

 disinfectants, used either for fumigation, to purify the air, or as anti- 

 septics, to prevent putrefaction or mortification. The Mechanical 

 agents, are demulcents, which sheathe sensitive parts from irritation ; 

 including emollients, which soften the parts, or render them more 

 flexible ; and diluents, which serve merely to dilute the animal 

 fluids, or render them thinner and less irritating. 



2. To Materia Medica, belongs the description of all simple 

 medicines, and their medical properties. We shall here classify 

 them, so far as we have room to mention them, according to the order 

 established in the preceding section. Among the stimulant medi- 

 cines, may be mentioned alcohol ; either concentrated, as in spirits of 

 wine ; or diluted, as in distilled liquors ; or modified by other sub- 

 stances, as in wine and other fermented liquors. Next to this, are 

 ether ; camphor; and the essential oils, as of peppermint, or turpen- 

 tine ; all of which are similar compounds of carbon, hydrogen, and 

 oxygen. Ammonia, and its carbonate, which latter is known as 

 hartshorn, sal volatile, or smelling salt, are stimulant and antacid at 

 the same time. Mercurial medicines, as calomel, and red precipi- 

 tate, are powerful stimulants, which should be used with the greatest 

 caution. Heat, electricity, and some mental emotions, may also be 

 classed with the stimulant medicines. 



Among the tonic medicines, are cinchonia, and quinia, sometimes 

 called quinine ; as also their salts ; all obtained from Peruvian bark ; 

 and found to be most important remedies in certain fevers. Several 

 astringent barks and roots, have tonic properties ; as nutgalls, quassia, 

 and snake root : and several astringent salts, of iron, copper, and 

 zinc, particularly the sulphate of iron, and its carbonate found in 

 chalybeate waters, belong to this class of medicines. Exercise, and 

 cheerful emotions, have also a tonic effect. Among the anthelmintics, 

 are Carolina pink root ; and cowhage, which is the down of a tro- 

 pical plant. The powder of tin, probably acts mechanically to de- 

 stroy intestinal worms; but as it is often poisonous, its use can in no 

 case be recommended. 



The most common emetics, are tartar emetic, the double tartrate 

 of antimony and potassa ; and ipecacuanha, the active principle of 

 which, called emetia, is milder than the preceding. Lobelia, or In- 

 dian tobacco, and sanguinaria, or blood root, have also emetic proper- 



