EXPECTORANTS. 483 



When we review the various measures classed under the 

 1st, 4th, 5th, 6th, and 7th preceding heads, we are enahled to 

 re-arrange several of the most important of them into new 

 groups with definite pharmacodynamical properties and im- 

 portant therapeutical bearings. These groups are (A) Expec- 

 torants ; (B) Antispasmodics ; and (c) Respiratory Sedatives. 



A. Expectorants. Expectoration, the discharge of the sputa, 

 or secretions and other products of the respiratory passages, 

 will manifestly vary with the amount and characters of the sputa, 

 and with the expulsive force which can he brought to bear upon 

 them. Measures are therefore called expectorants which increase 

 the absolute amount of sputum formed, which so modify its 

 characters as to facilitate its expulsion, or which evacuate it 

 with greater ease : the first and second kinds of expectorants 

 acting upon the glands, the third kind upon the muscular struc- 

 tures. Regarded otherwise, the expectorants will be found 

 sometimes to stimulate the respiratory centre, e.g. Ammonia and 

 Ipecacuanha, sometimes to depress it, e.g. warm, moist air. But 

 of greatest practical importance is the action of expectorants 

 upon the circulation; and according to their stimulating 

 or depressing influence in this respect, they are commonly 

 divided into (1) Stimulant expectorants, and (2) Sedative expecto- 

 rants. It must be clearly understood that "sedative" and 

 " stimulant " in this connection refer not to the respiratory, but 

 to the circulatory effect of the bronchial measures. 



(a) Stimulant expectorants include Ammonia, Scilla, all the 

 Volatile Aromatic oils, Oleo-resins, and Balsams enumerated 

 above; Strychnia, Alcohol, Senega, warm liquid food, and 

 moderate exercise of the body generally or of the chest. 



(b) Sedative expectorants include Alkalies, Iodides, Anti- 

 mony ; Ipecacuanha, and Tobacco ; warm, moist air ; and warm, 

 moist applications to the chest- walls. 



If we wished to construct other groups of expectorants we 

 might add : 



(c} Expectorants -with a sedative effect on nerves. These 

 are chiefly obtained by combining other expectorants with 

 Opium, e.g. Scilla and Opium, Camphor and Opium, Ammonia 

 and Opium, Ipecacuanha and Opium all of which combinations 

 are officinal, Antimony and Opium, etc. Warm drinks have 

 the same effect. 



(d) Expectorants which alter the chemical composition of 

 the sputa. This is a highly important group. Alkalies increase 

 the alkalinity of the sputa, and at the same time the water of 

 the bronchial mucus, and thus the liquidity of the sputa. They 

 constitute a special class called the Saline expectorants. 

 Sulphur, Iodine, all the Aromatic Oils, Oleo-resins, and Balsams, 



