292 DISEASES OF THE PLEURA. 



entered to take the place of the pus which has been evacuated by the 

 bronchi, the symptoms and course of pneumothorax are altogether 

 different from those described above. In such cases, especially in the 

 latter instance, there often are no subjective symptoms whatever, and 

 the malady is only discovered accidentally when the chest of the 

 patient is examined. When the quantity of air in the pleural sac is 

 large, physical examination gives the following results : 



Inspection. If we find that a consumptive patient (whom a few 

 days ago we left walking about, or whose attitude as he lay in bed 

 was perfectly unconstrained) now exhibits signs of great dyspnoea, 

 that he lies upon one side, anxiously avoiding all alteration of this 

 position, these symptoms alone (particularly if the change have taken 

 place suddenly) should awaken a strong suspicion that pneumothorax 

 has been established. Upon looking at the chest, even an unprac- 

 tised eye can mark the dilatation which it has undergone, the oblit- 

 eration of the intercostal furrows, and the absence of respiratory move- 

 ment upon the affected side, and, when the pneumothorax is in the left 

 pleura, that the cardiac impulse is visible to the right of the sternum. 



Palpation. Displacement of the heart toward the sound side, as 

 well as downward displacement of the liver, in pneumothorax of the 

 right side, is still more perceptible upon palpation. The pectoral fre? 

 mitus is generally quite imperceptible, and is always fainter upon the 

 affected side than upon the sound one. 



Percussion. Over the region of the pneumothorax the percussion- 

 sound is full, clear, and tympanitic, and when the pneumothorax is of 

 the right side it extends too far downward, and when of the left too 

 far inward. When the thoracic wall is very much disturbed, the 

 intensity of the pressure hinders the formation of regular vibrations, 

 and the sound is not tympanitic. So tense does the thoracic wall 

 sometimes become, that percussion does not produce any sonorous 

 waves at all, and, even when practised with heavy strokes, only gives 

 rise to a feeble, dull sound. Great stress has recently been laid upon 

 the change of pitch in the percussion-sound of pneumothorax occa- 

 sioned by the patient's lyin^ down or sitting up (JBiermer), it being 

 supposed that the diaphragm is depressed by the effusion, and the long 

 diameter of the pleural sac is increased, while in the erect attitude 

 (jBiermer, Gerhardt). I cannot help doubting the constancy of this 

 increase in the long diameter of the pleural cavity in the erect posture, 

 and indeed believe that, sometimes, the very reverse occurs, that is, 

 when there is a certain amount of exudation in the cavity. Finally, a 

 metallic clang is often heard upon percussion, especially when the 

 car is laid upon the chest during the operation. The percussion-sound 

 becomes dull, as far as the effusion extends, in a very few days. A 



