74 THE FARM DOCTOR, 



zephyr stirring dry leaves. Just behind the left elbow in horses 

 this murmur is absent and replaced by the sounds of the heart. 

 Between the upper and middle thirds of the chest it mingles 

 with the blowing sound anteriorly, but is unaccompanied by 

 that over the few last ribs. Percussion consists in drawing out 

 the resonance of any part by striking it gentle taps with a hard 

 object, the blows falling perpendicularly to its surface, and of a 

 force proportioned to the depth of the organ it is meant to 

 sound. Thus, for the surface, the gentlest taps with the tip of 

 the finger are wanted, while for the centre of the chest in large 

 animals, the closed fist may be advantageously used. For 

 intermediate depths the four fingers and thumb may be brought 

 together, in a straight line at their tips, and the surface tapped 

 with this. When a cavity, enclosed by a hard bony surface, 

 such as the nose, is being sounded, it is well enough to tap this 

 direct, but if the surface is soft, as in the chest of fat and fleshy 

 animals, a hard, solid body should be pressed firmly upon it, 

 and the taps delivered upon this. As the different parts of the 

 the right hand may be used for delivering the taps, so may the 

 two middle fingers of the left hand be employed to compress 

 the soft parts and receive them. The front of the fingers 

 should be applied against the surface, and the hard bony backs 

 turned out to receive the taps. If percussion is made over a 

 hollow space, like the nose or windpipe, the sound is drum-like; 

 if over an open, spongy tissue, like the lung, it is much less so, 

 but still full and clear ; but if over a solid body, like the thigh, 

 it is dead, or quite wanting in resonance. Behind the left 

 elbow such dull sound is met with in the horse, and, to a less 

 extent, in cattle ; and on the last ribs on the right side in cattle. 

 sheep, and pigs, a similar dullness is found in accordance with 

 the position of the liven Any increase, diminution, or loss of 

 resonance over particular parts thus becomes of great value as 

 indicating the healthy or unnatural state of the parts. But the 

 observer must learn this matter by experience on the healthy 



