444 SYMPTOMS OF DISEASE OF RESPIRATORY ORGANS. 



tion to the mucous membrane in any part of the air-passages, 

 but cliiefly the throat and larynx, by disordered conditions of 

 both intimate and accessory structures of these organs, by 

 reflex or propagated irritation from disorders in other and 

 distant organs, and by direct nervous disturbance. 



In studying cough its general character requires to be 

 regarded — (a) In respect of its mode of attack, whether de- 

 pendent upon some irritation conveyed to the parts, or 

 occurring independent of any appreciable cause ; (h) The 

 frequency of its occurrence, and whether of a few isolated acts, 

 or occurring in paroxysms ; (c) Its severity and apparent 

 accompanying conditions of pain ; (d) Its qualit}^, whether 

 irritating, barking, hoarse, cavernous, dry, or moist. 



For our guidance, the chief consideration is its special 

 character or quality ; and of this, the more important may be 

 grouped as ' dry ' or ' moist.' 



The moist or humid coughs are, as the name indicates, 

 associated with a damp or humid condition of the respiratory 

 mucous membranes. 



This kind of cough is usually attendant on the second stage 

 of congestive or inflammatory action in the middle and lower 

 air-passages, sometimes also of the upper. When the disease 

 is chiefly in the upper and middle portion of the air-passages, 

 the cough is full, sonorous, and prolonged. 



In some cases of sore throat, and in inflammation of the 

 lower and more minute air-passages, the full and sonorous 

 character is lost ; it is weak and feeble. 



The dry cough, with characteristic laryngeal sound, is in its 

 various modifications largely indicative of an irritated and 

 rather dry condition of the mucous membrane, and of the 

 earlier stages of inflammatory action. It is also the cough of 

 propagated or reflected irritation. 



In the earlier stages of active inflammation of the lar}'ngeal 

 and adjacent structures, it is prolonged and sonorous, becoming, 

 as the disease advances, harder from the increased tumefaction, 

 and then moist when secretion is established. During the 

 same stage of the process in the lower air-tubes, the cough is 

 hollow or tubal ; while, when the pulmonic structure is much 

 invaded, there is a short, scarcely audible, rather dull cough, 

 resonance seeming to be propagated through the solidifying 



