22 PATHOLOGY. 



ivith congestive pneumonia. Cold again acts as a sedative and 

 debilitant if long continued or severe ; it weakens tlie circulation, 

 especially that of the surface of the body, causes internal con- 

 gestions, and directly lowers all the vital energies; and the 

 most fatal cases of pleurisy and pneumonia are observed to 

 prevail during and towards the close of severe winters. A 

 temporary application of cold to the healthy animal is followed 

 by a favourable and invigorating reaction, but when long con- 

 tinued its effects are most injurious. 



