74 PRACTICE OF MEDICINE. 



bronchitis ; and that, for its prevention and alleviation, the treatment 

 must be conducted on this principle. 



Sijmploms. — Habitual dyspnoea, which, during the earlier periods 

 of the disease, is mitigated in summer, but returns in the winter 

 with increased violence : the complexion is of a dusky hue ; the 

 countenance has an anxious and melancholy expression ; the nostrils 

 are dilated and thickened ; the lower lip is enlarged, and its mucous 

 membrane everted and livid. The movements of the thorax are 

 irregular and habitually unequal ; inspiration is short, high, and 

 rapid ; but expiration is slow, incomplete, and, as it were, graduated; 

 there is thus a manifest difference in the duration of the two move- 

 ments. The shoulders are elevated and brought forward, and the 

 patient stoops habitually, a habit contracted in his various fits of 

 orthopnoea and cough ; thus, even in bed, we find these patients 

 sitting up, with their arms folded and resting on their knees, and the 

 head bent forwards, the object of which seems to be to relax the ab- 

 dominal muscles, and to substitute the mechanical support of the 

 arms for that of muscles which would interfere with inspiration. 

 During the fits, the respiration becomes convulsive. There is a 

 constant cough, returning in fits, usually dry, but often attended 

 with the expectoration of a viscid liquid, of a dirty gray colour. 

 This is one of the diseases long confounded under the name of 

 " asthma,'''' 



Physical signs. — The chest yields a morbidly clear sound on 

 percussion; it is not, however, tympanitic, as in pneumo-thorax, but 

 may be described as the maximum of true pulmonary sound. This 

 excessive resonance is not given equally at all points, as the disease 

 seldom extends to the whole lung. But although percussion indi- 

 cates the presence of air, the ear applied to the chest detects that 

 the air is not in motion, for there is very little or no vesicular 

 breathing. There is heard occasionally some large crepitation; this 

 was called by Laennec dry crepitation, and he supposed it to be 

 produced, like the crackling of a dry bladder, from the entrance of 

 air into the dilated vesicles. Dr. Watson, however, believes it to be 

 nothing more than the crepitation of large bubbles of mucus, arising 

 from the catarrh, which is almost always present. Where this dis- 

 ease is extensive, we generally find, owing to long-continued pul- 

 monary obstruction, that the right cavities of the heart are hyper- 

 trophied ; this latter fact will obviously account for the congested 

 and enlarged state of the liver which also occurs. 



Morbid appearances. — The ordinary appearance of an emphy- 

 sematous lung is a remarkable coarseness of the vesicular texture, 

 as seen through the pleura ; it is also elastic, lighter, and less cre- 

 pitant than usual, and does not collapse. In a greater degree, the 

 enlarged cells look like the vesicular lungs of cold-blooded animals, 

 and occasionally raise the surface of the lung into rounded inequali- 



