PEKCUSSION. 531 



Right side. The superior region, as compared with that 

 of the left side, differs only in this, that in applying percus- 

 sion behind the 13th rib, very little force must be employed, 

 as 'otherwise the arch of the colon will give a sound simu- 

 lating that of an emphysematous lung. The median region 

 may be said to correspond exactly to that of the left side. 

 The lower region is clear and resonant from the 5th to the 

 7th rib, but from the 8th to the llth it is nearly entirely 

 dull, from this part responding to the liver. 



Ox. Left side. The superior region is very resonant 

 over the 8th, 9th, and 10th ribs. If it be struck very gently 

 between the latter and the 12th rib, the diminished resonance 

 of the posterior border of the lung may be still brought out, 

 though, if struck at all forcibly in .this region, a tympanic 

 sound is produced, due to gas in the rumen. The median 

 region is very resonant over the 5th, 6th, and 7th ribs, much 

 less so over the 8th and 9th, and quite dull over the lower 

 third of the 10th, and half the llth; this dulness proceeds 

 from the abdominal organs. The lower region, unlike in 

 the horse, shows considerable resonance over the 4th, 5th, 

 and 6th ribs, from this part lying over the anterior lobes of 

 the right and left lungs, which almost completely envelope 

 the heart. From the 7th to the 9th ribs, the resonance 

 diminishes, and is entirely lost in the lower fourth of the 

 latter, as well as over all the ribs behind it. In young and 

 emaciated subjects, by drawing the limb forcibly backwards, 

 and applying the pleximeter as firmly as possible over the 

 first two ribs, a clear sound may be obtained. 



Right side. The resonance of the right side differs little 

 from that of the left; the resonance is sometimes perceptibly 

 less posteriorly on account of the presence of the liver. 



In very thin animals a clear sound is produced by percus- 

 sion in the fossse of the scapula. 



