CONGESTION OF THE IjUNGS. 



871 



blood passes the walls of the vessels through the tissues outside of 

 the vessels. The next change is the breaking down of the cellular 

 tissues— normal cells ; next a rapid growth or proliferation of ab- 

 normal cells. To go through symptoms : If an external injury, 

 for example, there would be, first, pain caused by the pressure 

 upon the nerves. The heat following would be caused by the 

 chemical changes that are going on within the part. The redness 



4$^ 



Fig. 766.— Bronchial tube, with its bronchules, and ultimate 

 ramifications (natural size). 



is due to the passing of the blood from the vessels into the tissues; 

 the swelling is due to the breaking down of normal cells and the 

 rapid formation of abnormal cells. The object in all cases, whether 

 internally or externally, is to equalize the circulation as quickly 

 as possible. 



There are two methods of treatment : If we know the cause, 

 as, for example, the animal having stood in a draught of air or 

 been exposed to cold, chilling weather, alcoholic stim.ulants would 

 be the best treatment, not only giving alcohol internally, but rub- 

 bing it on the legs, and cover the body with warm blankets. Rub 

 elbows and hocks to feet, by hand-rubbing or brushes, rubbing 

 quickly, and cover with warm flannels. If not successful, or if 



