46 The Lung Plague of Cattle. 



troubles. If kept quiet, such convalescents fatten rap- 

 idly. 



Far more frequently, in this country at least, a mass ol 

 lung is entirely lost, being divested of its vitality, enclosed 

 in a fibrous cyst, and slowly liquefied and absorbed 

 through a course of several months. These continue to 

 do poorly for a number of months and may yet entirely 

 recover, the whole dead mass having been finally re- 

 moved and the sac having contracted into a dense fibrous 

 structure. Even in this case if the patient has been able 

 to bear up under the continued drain, and has escaped 

 consumption and other risks, it may finally be successfully 

 fattened. 



Appearances of the Chest and Lungs after Death. 



If the disease is seen in its earliest stages the changes 

 are altogether confined to the tissue of the lung. From 

 the examination of the lungs of several hundred diseased 

 animals I can confidently afiirm that the implication of 

 the serous covering of the lung (pleura) is a secondary 

 result. In all the most recent cases we find the lung 

 substance involved and the pleura sound, while in no one 

 instance has the pleura been found diseased to the exclu- 

 sion of the lung tissue, or without an amount and char- 

 acter of lung disease which implied priority of occurrence 

 for that. Yet in all violent attacks the disease will have 

 proceeded far enough to secure implication of the pleura 

 as well, and hence we may describe the changes in the 

 order in which they are usually seen when the chest is 

 opened. 



The cavity of the chest usually contains a quantity o! 

 liquid varying from one or two pints to several gallons, 

 sometimes yellowish, clear and transparent, at others 

 slightly greenish, brownish-white and opaque or even ex- 

 ceptionally slightly colored with blood. This eifusion 

 contains cell-forms and granules, and gelatinizes more oi 

 less perfectly M'hen exposed to the air. 



