ACUTE DISEASES OF THE ORGANS OF RESFIJRATION. 217 



first for a short time detected. This peculiar sound arises from the dry- 

 roughened pleura of the lungs grating against the equally dry roughened 

 pleura of the ribs, 



Pleuritis is also marked by great irregularity in the temperature of 

 the extremities, portions of which may be cold, whilst other portions are 

 hot, and frequent alterations of temperature occur in the same part. 



In a period of time varying from two days to a week in favorable cases 

 the dryness of the pleura is relieved by an effusion of serum from the 

 overloaded vessels. The occurrence of the moist stage has not in itself 

 either a favorable or unfavorable significance. It is merely the course 

 through which every inflammatoiy attack passes, which does not at once 

 end in resolution. At this the second or moist stage the friction sound, 

 noted above as characteristic of the disease in its first stage, disappears ; 

 and the cough becomes loose and moist, and the extremities for a time 

 become warm. The pulse becomes less frequent, smaller and weaker, 

 the breathing less laboured, and the membrane of the nostril loses its 

 redness. 



In from about twenty-four to forty-eight hours after the occurrence of 

 the moist stage we may look for a decided change either for better or for 

 worse. 



437. Suhsidence of the attack. 



Subsidence of the attack will be indicated by the breathing becoming 

 less hurried, by the pulse becoming softer and more distinct, the tempe- 

 rature becoming lowered, and the cough less frequent, and by the 

 extremities continuing warm. As in most acute diseases recovery, when 

 a favorable change once takes place, is tolerably rapid. 



438. Increase of the attacJc. 



On the other hand persistence of the attack is indicated by the extremi- 

 ties, which had on the occurrence of the moist stage become warm, 

 again becoming and continuing cold, by a deep scarlet colour of the 

 membrane of the nose, by a discharge of straw-coloured serum from 

 the nostrils, by a thready wiry pulse, and by a rapid increase in the 

 symptoms of inflammation, which will soon terminate either in effusion 

 of serum, otherwise called water on the chest, or in exudation of lymph, 

 causing in some cases extensive adhesion of the pleura of the lungs to 

 the pleura of the ribs ; or very frequently in both. 



As in pneumonia, it is necessary to caution the inexperienced against 

 mistaking the earlier symptoms of either of these results for those of 

 subsidence of the attack. 



We reserve our notice of treatment until after the consideration of the 

 symptoms of Pleuro-pneumonia. 



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