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DISEASES OF THE RESPIRATORY ORGANS. 503 



crackling of pneumonia, and may be heard only in a very limited 

 spot in the beginning. We cannot too highly value this simple 

 symptom, as it gives the earliest and surest intimation that the 

 disease has begun. 



When you catch the inflammation in its earliest stage the mi- 

 nute crepitation which announces the commencing engorgement of 

 the part is heard mingled with the ordinary sounds of respiration. 

 This obscures the material sound, though it does not yet entirely 

 cover it — but as the inflammation advances, the crackling becomes 

 more pronounced, until at length it totally supersedes it. So long 

 as the natural sounds of respiration prevail over the crackling, we 

 may conclude the inflammation is slight. But the crackling does not 

 remain long in any part. As the case proceeds, the sound is less 

 and less hard, and at length not heard at all in that spot ; and it 

 may be succeeded by one of two very different sounds. Its place 

 "may be taken by the respiratory murmur again, in which case it 

 denotes the termination of the inflammation. But the crackling 

 may cease, and either no sound at all be heard in its stead, or a' 

 new morbid sound which I will presently describe ; and this teaches 

 us with absolute certainty, that the disease is growing more severe 

 and serious ; that the lung is becoming or has become hepatized, 

 that is, solidified, liver-like. 



The new sound is audible as a whiffing, like air blown through 

 a quill. Little gusts of air are puffed in and out ; often most dis- 

 tinct at the termination of a slight cough. The hepatized lung 

 allows the air to pass in the larger bronchial tubes, but has closed 

 up the smaller ones and the lung vesicles, wherefore the whiffing, 

 blowing, gusty sound of the breath as it enters and departs from 

 the large bronchi, which still remain open, and bronchial respi- 

 ration, as the new sound is called, is heard. By means of these 

 three sounds, and a knowledge of the position of the lungs, you 

 may easily master their condition by the sounds heard as you 

 apply your ear to different portions of the chest. 



In the majority of cases, the commencement of inflammation of 

 the lungs is marked by the animal's shivering, or having a chill, 

 followed by an increase of temperature of the body, and increased 

 frequency of pulse. A little later difficulty of breathing is appa- 

 rent, and the animal begins coughing. At first the cough may be 



