DISEASES OF THE KESPIEATORY ORGANS. 575 



organs, and very often the restlessness of the patient, render 

 this method of examination much less satisfactory than it 

 otherwise would be ; but, notwithstanding all these drawbacks, 

 auscultation is of immense advantage, and by it we are enabled 

 to arrive at conclusions that would otherwise be impossible. 



To become familiar with the knowledge to be acquired by 

 auscultation much time and labour must be devoted to it, first 

 on healthy, and afterwards on unhealthy animals; in fact the 

 ear must be trained by long experience. 



The stethoscope can be bought at any instrument maker's, 

 and the simpler it is the better. In applying it to the chest, its 

 funnel-shaped end is to be accurately and firmly applied to the 

 surface, and the opposite end in perfect apposition to the ear. 



When immediate auscultation is practised, care is to be taken 

 that the ear be accurately applied to the skin, or if the state of 

 the surface does not admit the ear, a single fold of a thin cloth 

 only should be allowed to intervene, as the rubbing of two folds 

 or surfaces may create a sound and puzzle the examiner. 



2. Percussion. — This process consists in striking upon the 

 surface with the view of eliciting sounds, by the nature of which 

 an opinion may be formed of the conditions of the parts beneath. 

 Like auscultation, percussion is either immediate or mediate. 

 The former was employed by Avenbrugger, and the latter in- 

 vented by M. Piorry, who gave the name of ''pleximeter" to 

 the intervening body. 



In immediate percussion, the ends of the fingers are brought 

 together and supported by the thumb, and the parts are struck 

 perpendicularly to the surface, or the parts may be rapped with 

 the knuckles of the closed hand, the force of the blows being 

 regulated by the depths of the parts to be examined, and the 

 size and delicacy of the animal. In the cat or dog gentle blows 

 with the tip of the middle finger are generally suflicient. 



In mediate percussion, the pleximeter is generally a flat, oval, 

 or circular piece of ivory or gutta percha, or the left index finger 

 of the operator, which is certainly the most convenient and best 

 intervening body which can be had. 



M. Poirson of Paris recommends that percussion should be 

 performed by means of a common sewing-thimble placed on the 

 middle or fore finger, so as to include a small portion of air 

 between the end of the finger and that of the thimble. The 

 intensity of sound elicited is said to be thus greatly increased. 



