DISEASES OF THE RESPIRATORY SYSTEM. 151 



It is called the pleuritic friction sound, and is heard on inspira- 

 tion and expiration. 



Second Stage. — There is an absence of all respiratory sound 

 at the affected part. Bronchial breathing above the line of the 

 trouble. The mucous click, or the metallic tinkling sound, can be 

 heard above the line of fluid or at the nostrils. It sounds like a pin 

 dropping in a metallic vessel, or a drop of water going through the 

 mouth of an open bottle. It was formerly supposed to be pathogno- 

 monic of pleurisy, but it may be heard in laryngitis. 



Third Stage. — The pleuritic friction sound returning (a rub- 

 bing and sticking sound), and the metallic tinkliiig sound getting 

 less and less as the fluid becomes absorbed. 



How is pleurisy diagnosed ? 



The pulse assumes a wiry character; the respirations are ab- 

 dominal, with a double expiratory act; the temperature at first 104° 

 to 106° F., then oscillating between 103° and 101° F. 



Flatness on percussion in the second stage; on auscultation 

 during the first stage, the pleuritic friction sound heard on inspira- 

 tion and expiration, while, during the second stage, there is an 

 absence of all respiratory sound below and bronchial breathing 

 above. 



During the third stage the returning of the pleuritic friction 

 sound. 



What diseases may be mistaken for pleurisy ? 



Pneumonia and bronchitis, principally. 



What is the differential diagnosis between pleurisy and 

 pneumonia ? 



Pleurisy is a bilateral disease, while pneumonia, in ninety-nine 

 cases out of one hundred, is unilateral. 



Pleurisy, temperature is high at the beginning, but later 103° 

 to 101° F., while in pneumonia the temperature is high all through 

 —104° to 106° F. 



In the first stage of pleurisy, on auscultation, the pleuritic 

 friction sound is heard, while in pneumonia the crepitant rale. 



In the second stage of pleurisy there is flatness on percussion 

 over the fluid, limited above by a horizontal line on both sides of the 

 chest, whereas, in pneumonia, dulness over the affected part, limited 

 by an uneven line (generally one side). 



