pleurisy equally prevail — aloug with considerable hepatization of 

 one of the lungs, and sometimes, though rarely of both, a large 

 quantity of serum will be found in the cavity of the chest ; while 

 a sort of adhesive inflammation will be set up, and portions of 

 lungs, pleuro, and diaphragm are found attached in one diseased 

 mass to the ribs. 



4. — Auscultation and Percussion. 



With quiet cattle, these tests (auscultation and percussion) 

 can be employed for the purpose of ascertaining whether or not 

 they are affected. 



(1.) — Auscultation. 



Although the changes caused in the chest and its organs by 

 pleuro-pneumonia exist before any marked symptoms show them- 

 selves in the living animal, they are generally indicated by certain 

 sounds which, to the practised ear, disclose the true state of the 

 lungs and the other organs affected. 



One or other and sometimes all of the following indications will 

 present themselves on applying the ear to the side of the animal's 

 chest: — (1st) The healthy breath murmur. (2nd) The crepitus. 

 (3rd) The absence of sound. (4th) The sawing, rubbing, or 

 friction sound. (5th) The deep gurgling and irregular sound. 

 (1.) The natural sound which meets the ear applied to the 

 side of the chest of a healthy animal well conveys the 

 idea of that which is actually taking place, — of air en- 

 tering a vast number of minute cells ; and is what may be 

 termed a smooth, soft, bellows-like murmur. 

 (2.) When, again, one of the lungs is affected, and the disease 

 is confined to that organ, the breath sound in it is louder 

 and coarser than usual, and conveys the idea of the lung 

 becoming impermeable to the air. This is the case ; for, 

 as inflammation of the substance of the lung progresses, 

 the air enters the cells with difficulty, owing to the lymph 

 being poured into them and also into the spaces be- 

 tween them. Then the air, forcing its way into the cells 

 under these circumstances, gives rise to the peculiar 

 rushing and crackling sound termed crepitus, which is 

 very distinct, but only heard during inspiration. 

 (3.) As the disease progresses, some portions of the lung 

 emit no sound whatever — neither the healthy murmur 

 nor the crepitus — and this arises through the effusion of 

 lymph involving the air-cells and substance of the lung, 

 in the silent portions of it, in general destruction. By 

 this time a peculiar blowing or rushing sound will be 

 detected in other parts of the chest. 



