THE RESPIRATORY APPARATUS. 329 



appear, and the patient becomes very weak, and death 

 from asthenia results. Accumulation of fluid in the chest 

 rarely occurs except as a result of previous inflamma- 

 tory action. The most valuable indications of its presence 

 are afforded by auscultation and percussion. The lattei 

 test gives a dull sound as high as the fluid has risen in 

 the chest ; the former an absence of all sound below the 

 same line. 



Results. — Eesolution frequently follows proper treat- 

 ment, and the deposits become reabsorbed. If the 

 disease has existed for some time some of the deposits 

 will have become organised uniting the pulmonary with 

 the costal pleura. Often we find that the pleura of a healthy 

 animal is opaque in patches, or has slight stringy lymph 

 bands connected with it, as a result of a previous attack 

 of pleurisy. Death may take place in the earliest stage 

 from fever, or in the later stage after prolonged disease 

 from collapse of the lungs, in consequence of pressure 

 from effusion, or it may be the culmination of progressive 

 debility. 



Autopsy. — At first a congested condition of the pleura, 

 causing reddening and dryness, either diffused, localised, 

 or in patches ; later, opacity and lymph deposits, in various 

 stages of organisation, investing the pleural surface, 

 uniting the parietal and visceral layers of the membrane, 

 hanging as shreds in the effused lymph, or sepa- 

 rated as flocculi, which float in the effused serum, which 

 varies in quantity (sometimes amounting to several gal- 

 lons), colour (straw coloured or red), and turbidity. 

 Occasionally pus is found in the pleural sac, when the 

 condition is known as Empyema (but this, when it does 

 occur, is generally due to a ruptured abscess of the lungs, 

 for instance). The pleura may, in very acute cases, be 

 gangrenous, its lymphy deposit dark and wanting in con- 

 sistency, and of an offensive odour. In hydrothorax the 

 lung or lungs are small, firm, and somewhat congested. 



Treatment, — That suggested for broncho-pneumonia 

 may be adopted, with the following modifications : — 

 Bleeding is not called for; laxative agents may be freely 



