70 PRACTICE OF MEDICINE. 



spiratory murmur, it is a certain indication that the pneumonia has 

 made progress, and that it has a tendency to pass to the second 

 stage. These phenomena soon change, either by the resolution of 

 the disease, or by its making further progress. In the former case, 

 the crepitation diminishes in extent and intensity ; the murmur of 

 respiration approaches its natural state ; the sound of the chest be- 

 comes less dull, and its movements more regular ; and, finally, a 

 large crepitation is evident, which indicates an approach to conva- 

 lescence. 



In the first part of this stage the sound on percussion is only 

 slightly impaired ; but as the engorgement advances, and the pro- 

 portion of air in the inflamed spot of lung is diminished, it becomes 

 more dull over the corresponding part of the chest. 



Secoyid stage. — The second stage of pneumonia is that in which 

 the lung presents that change which is called by Laennec red hepa- 

 tization. In this condition, the cells being obliterated, while the 

 large tubes remain pervious, dulness on percussion, bronchial respi- 

 ration, and a loud resonance of the voice {bronchophony)^ are pro- 

 duced ; the extension or intensity of these signs furnishes, within 

 certain limits, an accurate measure of the extent or intensity of the 

 disease. The bronchial respiration specifically marks the second 

 stage of pneumonic inflammation. It resembles the sound produced 

 by blowing through a crow's quill, and is frequently so loud as to 

 amount to a whistle. If the inflammation is extensive, the respira- 

 tion is puerile in other parts of the lung. In order that this bronchial 

 respiration should be produced, not only must there be solidity of 

 the lung, but a certain expansion of the side must also take place; 

 for, if the whole lung becomes solidified, the bronchial respiration 

 ceases, and the signs then are, universal dulness, absence of the 

 respiratory murmur, and resonance of the voice. The voice is much 

 modified in its resonance, and this modification is not properly that 

 of segophony, nor pectoriloquy ; it approaches more to broncho- 

 2')hony. 



If the patient recovers from the second stage, and the infiltration 

 diminishes, so that the air is again admitted to the minute tubes and 

 vesicles, this is announced by a return of the small crepitation^ which 

 is of course favourable. {Crepitus redux.) 



Third stage. — In the third stage, the diseased lung becomes infil- 

 trated with a purulent matter, which is generally consistent at first, 

 but soon acquires the liquidity of common pus. In this stage, a 

 peculiar muco-crepitating rhonchus is heard, at first in some points, 

 then in the whole of the affected part. 



Of abscess. — In the infancy of pathological anatomy, the forma- 

 tion of an abscess in the lung, as the result of acute or chronic in- 

 flammation, was considered a very common thing. The common 



