PHYSICAL SIGNS OF BRONCHITIS. 59 



indicate a coryza, or a raucity and dryness in the throat) are of the , 

 dry kind ; sometimes a small tvhistlmg or hissing : sometimes like 

 the prolonged note of a violoncello, and sometimes the cooing of a 

 dove. When the membrane begins to secrete, the sounds above 

 mentioned gradually disappear, and are replaced by moist or crack- 

 ling ones produced by the successive formation and rupture of bub- 

 bles in the air tubes. It sometimes happens that, during the course 

 of a bronchitis, we suddenly cease to hear, in a certain extent of the 

 lung, either the natural sound of the pulmonary expansion, or the 

 crepitation. In this same part where the ear no longer hears any 

 murmur, the chest when percussed retains its usual sonorousness. 

 The explanation is, that the tube leading to a considerable portion 

 of lung has been temporarily blocked up by mucus ; but it may often 

 be cleared by a vigorous cough. This at once distinguishes bron- 

 chitis from almost all other affections of the lungs. Thus, though 

 percussion gives no direct result in this disease, its employment is of 

 importance in the particular diagnosis. For example, if a person has 

 had a severe cough, fever, hurried and difficult breathing for some 

 days, and the chest still sounds well, the great probability is, that 

 the disease is bronchitis. 



Morbid appearances, — After a mild and recent bronchitis, there 

 is found some redness in a circumscribed portion of the mucous 

 membrane ; particularly towards the termination of the trachea and 

 commencement of the bronchi. If the inflammation has been more 

 intense, the redness extends to a greater number of tubes ; and to 

 some of the smaller ramifications. It frequently occurs that this 

 redness is exactly limited to the bronchi of only one lobe ; it is the 

 bronchi of the upper lobe which appear more particularly disposed 

 to become inflamed. The red colouring of the bronchi sometimes 

 presents itself in the form of a fine injection, which seems to exist 

 simultaneously both in the sub-mucous cellular tissue and in the 

 mucous membrane itself; sometimes vessels are no longer distin- 

 guished, but only a number of small red points, crowded together, 

 and collected round each other ; sometimes there is observed a uni- 

 form red colour. Frequently the redness exists only at intervals, in 

 the form of bands or separate patches, which constitute, as it were, 

 so many circumscribed inflammations, between which the mucous 

 membrane is white and healthy — a form of inflammation similar to 

 that so frequently observed in the intestines. When the inflamma- 

 tion is chronic, the mucous membrane generally loses its bright red- 

 ness ; it presents a livid, purple, brownish tint. -It is very remark- 

 able, that in persons presenting all the symptoms of an inveterate 

 chronic bronchitis, with puriform expectoration, the mucous mem- 

 brane of the air tubes is scarcely of a rose colour, or is sometimes 

 even perfectly white through its whole extent. According to Bayle, 

 this white state of the mucous membrane is not rare in pulmonary 



