100 CLINICAL DIAGNOSTICS. 



respiratory frequency is combined with difficult inspiration 

 and expiration (inspiratory and expiratory dyspnea). It is 

 the most common form of dyspnea and attends all severe 

 diseases of the respiratory tract (pneumothorax, hydrothorax) 

 and also those diseases which have no primary seat but whose 

 course is accompanied by a severe intoxication of the blood 

 with COo — as in many of the infectious diseases. 



In pronounced mixed dyspnea there is a marked flap- 

 ping of the nostrils. At the beginning of inspiration both 

 wings (medial and lateral) are greatly distended. At the 

 end of the inspiratory movement they again collapse. How- 

 ever, the forced out-flow of air at expiration, which imme- 

 diately follows, forces the medial wing, which is in its path, 

 outward and upward causing a second movement of this 

 wing to occur. 



According to the seat of the respiratory obstruction one 

 speaks of a nasal, laryngeal, tracheal and pulmonary dysp- 

 nea. 



II. The Breath. 



An examination of the air breathed out by the lungs is 

 of diagnostic importance in many morbid conditions. Xor- 

 mally the air is emitted from the nostrils in two odorless cur- 

 rents of equal size. The two deviations from the normal are : 



1. The air currents from both nostrils are not of equal 

 size. Where one of the currents is smaller (of less volume) 

 than the other, it points to a narrowing of the nasal 

 passage of that side. Xot infrequently a blozcing sound 

 accompanies the inspiration. The passages may be con- 

 stricted by thickenings or swellings of the mucous membrane 

 or by tumors. 



2. The breath has a bad odor. A bad odor from the 

 nostrils is always a sign that putrid decomposition is taking 

 place in the air passages. It may emanate from various parts 

 of the respiratory tract. The odor is either putrid {fetid} 

 or carious. It is observed: 



