484 MATER i A MEDIC A AND THERAPEUTICS. 



are excreted, as such., or as their products, along -with an in- 

 creased flow of mucus ; and most of these, especially the 

 aromatic substances, have an antiseptic, deodorant, and dis- 

 infectant effect on the secretion, and on the surface from which 

 they are given off. They may he classed as the Disinfectant 

 expectorants. The water of the bronchial mucus is increased 

 in almost every instance of increased secretion, hut specially by 

 Alkalies, Iodine, and Antimony, which thus possess the 

 valuable property of increasing the liquidity of the sputa. 

 Lastly, Acids tend to diminish the amount of water, and thus 

 the total amount of sputum, i.e. to " dry up " the secretion. 

 They may be called anti-expectorants. 



B. Anti-spasmodics. These comprise a great variety of 

 measures which have the common effect, directly or indirectly, 

 of relaxing the muscular coat of the bronchi and the dia- 

 phragm. They are : (a) the various depressants of the respiratory 

 branches of the vagus mentioned above (4#), such as heat, 

 Iodides, Alkalies, etc. () The depressants of the other afferent 

 nerves to the respiratory centre (5), especially warm applica- 

 tions to the chest- walls. (7) The depressants of the respiratory 

 centre itself (6) Alcohol, Ether, Chloroform, Opium, etc. (5) 

 The direct nervo-muscular depressants bronchial (4 d], such as 

 Atropia, Tobacco, Amyl-nitrite, etc. ; and parietal (7), Conium, 

 etc. All these substances are distinctly depressant or sedative ; 

 but we have still another group of bronchial antispasmodics (e), 

 which are perhaps the most powerful of all, viz. some of the 

 expectorants, such as Ipecacuanha, Senega, and Tobacco, which 

 after momentarily increasing the spasm, cause a rapid and 

 profuse flow of mucus from the bronchial wall, thus relieving 

 the fulness of the vessels, provoking cough, and inducing 

 expulsion of the cause of the spasm. 



c. Respiratory sedatives. These measures deserve a special 

 name. The depressants of the afferent branches of the vagus to 

 the brain, such as Opium, Ether, Chloroform, etc., not only act as 

 antispasmodics and muscular depressants, i.e. prevent bronchial 

 spasm, widen the tubes, and arrest cough, but also prevent or 

 relieve pain and other distressing sensations referred to the 

 respiratory organs. The most rational kind of pulmonary 

 sedatives, however, are the expectorants above enumerated, 

 in cases where the cause of the distress can be removed. A 

 combination of the two classes will manifestly answer best in 

 most instances. 



III. PATHOLOGICAL RELATIONS. 



The disorders and diseases of this system fall readily into 

 two great classes, according as they affect (1) the respiratory 



