BRONCHITIS. 93 



from its situation within the lungs it is less exposed than 

 within the head, still is it much under the influence of 

 atmospheric changes and noxious inhalations. Independently, 

 however, of these causes, there are others which in a peculiar 

 degree operate upon the bronchial membrane. It is well 

 known that this membrane, so vast in its superficial extent, 

 is closely allied in its function of secretion with the skin; 

 and not with the skin alone, but with other mucous 

 membranes of the body as well, particularly with the one 

 lining the alimentary canal. Cold or wet suddenly applied 

 to the surface of the body, especially when heated, checking 

 or suppressing perspiration, may, on the principle of deri- 

 vation, throw an inflammation upon the bronchial membrane, 

 or upon that of the bowels, and the two irritations, bron- 

 chitic and gastro-enteritic, may exist simultaneously. It is 

 this known sympathy between these two membranes which 

 deters us from giving aloes or anything likely to irritate the 

 bowels in bronchitis; being in very great danger of becoming 

 troubled with diarrhoea, if we do, at the same time. Bron- 

 chitis may proceed from other disease of lung or pleura, 

 though its ordinary concomitant or precursor is catarrh and 

 laryngitis. Now and then it supervenes on strangles. 



Catarrhal bronchitis is the ordinary form the disease 

 assumes. The horse is said to have "taken cold,^^ and 

 begins to show signs of catarrh; his prevalent symptom, 

 perhaps but now commencing, being sore throat, proceeding 

 from irritation of the membrane of the larynx and fauces, 

 which speedily spreads down that of the windpipe into the 

 larger bronchial tubes, and occasions, in addition to the sore 

 throat, shortness and oppression of breathing. The discharge 

 from the nose, which at first is but slight, and of aqueous or 

 muco-watery description, in three or four days becomes of a 

 purulent as well as mucous nature, and is greatly augmented 

 in quantity: the symptoms of catarrh and laryngitis gradually 

 abating and merging into that short and laborious breathing 

 which clearly denotes high bronchial and pulmonary irri- 

 tation. Whenever he coughs, which he does more now, 

 matter is thrown out in increased quantity from the nose ; 



