CHAP. I.] PREDISPOSITION TO TAKE COLD. 223 



to acquire catarrh in its worst forms by some pre- 

 vious misfortune — as adhesion, &c. A simple cold 

 consists in slight inflammation of the membrane 

 which lines the nose, windpipe, &c. the functions 

 of which membrane in health are described in the 

 34th section, chap. ii. together with the manner in 

 which the disease is engendered and conducted 

 downwards. As we find in all other inflammatory 

 disorders, variations in the symptoms occur, ac- 

 cording to the previous constitution or evils of the 

 individual, and its actual condition — much more 

 than is attributable to an adverse season, or the im- 

 mediate cause of disease. For example, if two equal 

 animals be exposed to a chilly night air, that horse 

 which had performed a journey previously to turn- 

 ing out, would catch a cold for certain, — the other 

 most probably would escape ; but, if both had per- 

 formed the same journey, let us suppose, and one 

 of them laboured under the constitutional defect of 

 "adhesion of the pleura," (see page 100,) he would 

 acquire the more malignant cold, known as " in- 

 flammation of the lungs," — his less unhappy mate a 

 simple cold. 



If the cold extend no farther than a check upon 

 the mucous secretion of the membrane that lines 

 the nose, a purulent discharge is first observed 

 in the morning, his eyes become dull and a little 

 bleared ; and if the discharge does not run off the 

 cold, in twenty-four hours a short cough denotes 

 that the inflammation is creeping onwards, and 

 has reached the pharynx — or chamber of entrance 



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