66 INFLUENZA. 



branes, with a small amount of pale, straw-coloured jfluid in 

 the pleural cavities, to much thickening of the covering mem- 

 brane, extending to a deposition over more or less of its surface 

 of a soft, ill-formed, aplastic, yellowish-coloured lymph, so 

 matted and arranged over the diseased portions as to form 

 irregular and variously sized loculi, or spaces containing fluid 

 with a greater amount of effusion in the pleural sacs ; this 

 fluid varying in colour according to the amount of blood it 

 may contain, in which there occasionally float shreds of soft, 

 ill-formed, and partly adherent lymph. 



This want of capacity for organization is peculiarly charac- 

 teristic of the lymph eftused in influenza, and indeed in all 

 inflammatory actions accompanying epizootic diseases. It is 

 very distinctive when contrasted with the exudation of ordinary 

 pleuritis or pneumonia. Seldom in this epizootic fever have 

 we the well-marked fibrinous adhesions between the pleiu^al 

 surfaces so often seen in sporadic inflammation of the mem- 

 branes of the chest. 



In other cases, although the animal may have lived for 

 several days after the chest complications have been fairly 

 developed, there may be no encrustation of the pleune with 

 flocculi of lymph; on the contrary, these membranes may remain 

 perfectly smooth, only the colour altered to a dark metallic hue, 

 while the fluid in the cavities is somewhat turbid and of a 

 foetid smell. 



These changes in the pleural membranes, and the eftusion 

 of fluid in the pleural sacs, may occur in a comparatively short 

 time, and be unaccompanied with much textural change of 

 lung-tissue. The period of time occupied in the accomplish- 

 ment of these and other changes of structures within the chest 

 is a question with which we as practitioners, liable to be cited 

 in courts of law as skilled witnesses, ought to be conversant. 

 When the lungs are inflamed in their intimate structure, it is 

 rarely in the entirety of the organs, rather in portions or 

 sections, often at the inferior or lower portions ; and when so 

 involved, the inflammatory exudate in this true pulmonic 

 structure is of the same aplastic and undecided character as 

 respects organization as when occurring in connection with 

 the pleural membranes. On being divided or cut into with a 

 knife, we do not find that firm and distinct cohesion of parts 



