PHYSICAL DIAGNOSIS OF THE LUNOS. 



109 



Fig. 34. 



diseases; while in catarrhal and croupous pneumonia, and also in 

 certain forms of bronchitis, we find the excretion is thick and 

 firm, and accompanied by dry, laborious coughing-spells, and at 

 the end of the cough there is a swallowing movement. In hemor- 

 rhage of the lungs the cough is accompanied with more or less 

 foamy blood from the nostrils and mouth, and in some cases symp- 

 toms of choking ; a slight hemorrhage may escape our observation, 

 as the blood is generally all swallowed. 



Percussion of the Thorax. Percussion (tapping) is performed 

 by means of a percussion-hammer and an ivory or metal plate 

 (pleximeter) (Fig. 34). Lay the plate close to 

 the wall of the chest, and, with the hammer in 

 the other hand, strike the plate a number of light, 

 quick taps; the fingers can also be used, and are 

 preferred by some. Place the index or middle fin- 

 ger of the left hand firmly on the chest-wall, and 

 with the index-finger of the right hand tap on the 

 finger of the left hand. 



The limits of percussion are given in Figs. 32 

 and 33; but it must be taken into consideration 

 that on expiration the posterior limit of the lungs 

 is carried forward of the dotted line and not ex- 

 tending to the last rib; and, also, when the stomach 

 or intestines are very much filled with gas, crowd- 

 ing the diaphragm forward, lessens the extent of 

 the lungs. In percussion we make the distinction 

 between a clear, loud, normal lung sound and a 

 tympanitic, dull, or solid sound of disease. The 

 clear normal sound of the healthy lung is heard 

 all over the thorax, the volume of sound depend- 

 ing on the thickness of the lung at the particular 

 part being examined. The muscular layers of the 

 chest have a certain effect on the sound, very thick walls less- 

 ening the sound to a certain extent; the sound is more or less 

 dull over the shoulder-blade, sternum, and back; the posterior 

 borders of the lungs often have no perceptible sound, as they are 

 so thin. 



A dull, muffled sound, which has been mentioned in the above 

 classification, is heard in the following conditions: In the tissues 



Pleximeter. 



