118 PEACTICE OF EQUINE MEDICINE. 



Define mensuration. 



The act of measuring with a tape, and is seldom used, as it is 

 of no practical importance. It consists of measuring from the 

 withers to the sternum on either side, and comparing. 



What is succussion ? 



It is a splashing sound, heard when the thoracic or abdominal 

 cavity contains a large quantity of fluid and the body is given a 

 sudden or jerky movement, the ear or hands being applied over 

 the walls of the cavity. 



The sound resembles that produced by the shaking of a keg 

 partly filled with water. 



Succussion is useful in the smaller animals, as they can be 

 shaken to better advantage. 



Define percussion. 



This is the act of striking a part to ascertain the composition 

 of the structures. Percussion is very important, and yields much 

 information which is of value in making a diagnosis. 



What are the methods employed ? 



There are two — the immediate and the mediate. 



Define each. 



The immediate (also called direct percussion) is performed by 

 directly striking the walls of the thorax with the fingers, but this 

 method is not much used. 



Mediate, or indirect percussion, is where some medium (as the 

 fingers, pleximeter, etc.) is placed over the part percussed and struck 

 with the fingers or a hammer. 



The so-called digital percussion is, in ordinary practice, prob- 

 ably the most practical, and the stroke should be performed from 

 the wrist and perpendicularly to the surface. 



What are the objects of percussion ? 



We percuss to obtain sounds which vary with the degree of 

 elasticity or resistance of the parts percussed. 



What are the principal sounds elicited ? 



They are the tympanitic, the dull, and the clear, and, to appre- 

 ciate the difference, one must become familiar with the intensity, 

 character, and pitch of these sounds. 



