DIAGNOSTIC SYMPTOMS OF THORACIC INJURIES. 481 



dition, because infective material, entering with the air, may produce 

 severe inflammation. Air, entering the thorax through wounds, 

 is more apt to be infective than that admitted through the lungs, 

 which is purified as it passes over the respiratory mucous membrane, 

 much in the same way as air entering a bottle may be filtered by a 

 cotton- wool plug. The emphysema in the neighbourhood of chest 

 wounds is usually of little importance. 



(2) Haemothorax, or the presence of blood in the pleural sac, 

 arises either from rupture of vessels (intercostal) in the wall of the 

 thorax, or from injury of the lung or heart. Large quantities of 

 blood in the thorax may certainly produce sudden death by com- 

 pressing the lungs and inducing suffocation ; but even a small 

 quantity is dangerous, because organisms may reach it either through 

 the chest wall or lung, and produce septic pleurisy. The simul- 

 taneous existence of hsemothorax and pneumothorax accordingly 

 renders prognosis doubly grave. 



(3) Pleurisy results from the injury, and from the wound 

 becoming infected. It may thus arise either from the external or 

 the lung injury, and will evidently be favoured by foreign bodies 

 remaining in the wound, and by difficulties in carrying out antisepsis. 

 Pneumonia only results in cases where the lung is simultanously 

 injured, and occasionally happens in cases of complicated fracture 

 of the ribs. Cadeac describes a case of pyothorax in the horse, which 

 was treated by washing out the thorax. During the operation a 

 glass tube about 4 inches in length and T | inch in diameter slipped 

 into the cavity. Seven ribs were resected, allowing the entire hand 

 to be introduced and even the heart to be felt, near which the glass 

 tube was found. It was removed and the wound healed. On sub- 

 sequent post-mortem examination the affected half of the lung was 

 found entirely adherent to the pleura costalis ; the lung itself was 

 healthy. 



Symptoms. In determining whether a penetrating wound of the 

 chest exists, one must not immediately have recourse to probing, 

 nor should one, under any circumstances, proceed to explore with 

 uncleansed fingers. Probing a chest wound is generally condemned, 

 as perforation of the still uninjured pleura costalis may be produced 

 with the probe, and such examination may introduce infective 

 material into the thoracic cavity even where the wound has been 

 carefully cleansed. The question must therefore be answered by 

 first considering the other symptoms. One should make — 



(1) An examination of the position and condition of the wound 

 and of the body which has produced it, as well as the method of its 



B,S. I 1 



