PHARMACOLOGY. 415 



ties. Among the stronger cathartics, are elaterium, colocynth, gam- 

 boge, and aloes; but one more frequently used is Epsom salt, or the 

 sulphate of magnesia. Pure magnesia, and its carbonate, are milder 

 cathartics ; the former being an excellent laxative. The most im- 

 portant vegetable cathartics, are castor oil, obtained from the castor 

 bean ; and rhubarb, and jalap, which are the roots of foreign plants. 

 Calomel, or the protochloride of mercury, is both a purgative and 

 anthelmintic ; or, if taken in very small dose, it has general stimulant 

 and alterative effects ; like those of metallic mercury, and its oxide, 

 in the blue pill. 



Among the reputed diaphoretics, are ipecacuanha, and tartar 

 emetic, when taken in very small quantity. The former, mixed with 

 opium and sulphate of potassa, forms the sudorific medicine called 

 Dover's powder. The acetate, and carbonate of ammonia ; and 

 nitric ether, often called sweet spirits of nitre ; also produce perspi- 

 ration : and better than these, in some cases, are warmth, exercise, and 

 friction. Among the diuretics, are several salts of potassa and soda ; 

 and several vegetables; as the meadow saffron, foxglove, juniper 

 berries, and squills. The principal errhines, are snuff, euphorbium, 

 and white hellebore : and among the expectorants, we may name am- 

 moniac, assafoetida, squills, and the balsams of Peru and Tolu. In- 

 halations of ammonia, vinegar, or tar, in the state of vapor, may also 

 promote expectoration. The chief sialogogues are tobacco, horse 

 radish, and the sweet flag; the habitual use of which is however 

 injurious to digestion. The mercurial medicines also act as sialo- 

 gogues, when taken in sufficient quantity. 



Among the sorbefacient medicines, are iodine, bromine, ammoniac, 

 and galbanum : and absorption of the fluids may also be promoted 

 by compression, or friction. Of revellent medicines, ammonia, 

 mustard, cayenne pepper, and Burgundy pitch, are used as rubefa- 

 cients, producing local excitement or irritation. The Spanish fly is 

 sometimes used as a vesicant, to raise blisters ; and Croton oil, as a 

 suppurant, producing pustules or sores. Lunar caustic or the nitrate 

 of silver, and lapis causticus, or caustic potassa, are used as escha- 

 rotics, for removing unsound flesh. Among the antispasmodics, are 

 castor; musk; assafoetida; and sulphuric and nitric ethers ; which 

 exert a peculiar soothing effect on the nervous system. 



Of sedative remedies proper, venesection, or blood-letting, is 

 most frequently employed ; though it should be with caution. 

 The inhalation of diluted nitrogen, hydrogen, carbonic acid, or 

 carburetted hydrogen gases, has also a, sedative effect. Among the 

 narcotics, opium, or its active principles, morphia and narcotina, are 

 frequently used. Laudanum, is a strong tincture, or alcoholic 

 infusion of opium ; and paregoric, is a much weaker tincture of 

 opium, with camphor, and other ingredients. The ethers, may have 

 a narcotic effect, as in Hoffman's anodyne ; and hops, and tobacco, 

 are also used as narcotics, both externally, and internally. The 

 refrigerants most employed, are cooling drinks, or cold external 

 applications. Nitre, and borax, have also a cooling influence, in 

 proper cases. The nauseant medicines, are chiefly emetics admi- 

 nistered in very small doses. 



