Percussion . 183 



rib ; this diminishes to the ninth, behind which it is usually 

 replaced by a dullness due to the presence of food in the anterior 

 part of the paunch. By drawing back the limb percussion may 

 be employed over the first and second ribs as well. 



In the lower third the first two ribs can be examined and a 

 clear sound should be educed. On the 4th, 5th, and 6th ribs 

 there is a full resonance, the heart being here covered by lung 

 tissue, contrary to the condition in the horse. From the seventh 

 the sound becomes duller and the dead sound from the food in the 

 rumen characterizes the lower fourth of the ninth rib. 



Right side. From the shoulder the resonance gradually de- 

 creases in the upper third to the eleventh rib, beyond which the 

 sounds obtained are only from abdominal organs. In the middle 

 third considerable resonance is met with over the first and second 

 ribs, it is very full and clear over the 5th, 6th, and 7th, whence 

 it decreases and is quite lost behind the loth. In the lower third 

 a clear sound can be elicited over the ist, 2d, 4th, 5th, and 6th 

 ribs ; this is lessened over the 7th and 8th, and completely 

 lost behind the 9th. Any but the slightest blows over these 

 three last ribs brings out the dull, solid sound from the liver. 



A very full paunch greatly increases the anterior convexity of 

 the diaphragm, and compresses the lungs into the anterior part of 

 the chest. If the contents of the rumen are solid the resulting 

 dullness on percussion might be mistakenly supposed to indicate 

 consolidation of the lung. This source of error must be care- 

 fully guarded against. 



Sheep. Percussion in the sheep differs from that in the ox 

 chiefly in the following particulars : The diaphragm being at- 

 tached to the last rib, as in the horse, the diminishing resonance 

 of the lung may be traced as far back as in that animal. Thus a 

 pulmonary sound can be obtained in the upper third as far as the 

 last intercostal space, in the middle as far as the second last, and 

 in the lower as far as the fourth from the last. Over the lower 

 part of the fifth and sixth ribs on the left side the resonance is 

 remarkably clear owing to the great relative thickness of the an- 

 terior lobe of the left lung which here covers the heart. 



Pigs. In fat pigs the results are almost negative. In lean 

 animals the middle third on each side gives out a clear resonance 

 behind the shoulder as far as the seventh rib, from which it 



