328 THE ANIMALS AND MAN 



is sufficient to check the flow of blood. If a vein is cut the 

 blood will simply ooze out and may of itself form a clot 

 that will stop the wound; if not, the blood flow may be 

 stopped by applying a bandage over the wound, first disin- 

 fecting it and drawing the edges of the wound together. 



In the case of a bruise, the skin is not broken, but the 

 tissue or blood-vessels beneath the skin are crushed. This 

 may cause a swelling and a dark appearance by the collection 

 of blood and lymph at the spot. Gentle rubbing or a hot 

 or ice-water application will ease the pain and keep down 

 the swelling. 



Effects of alcohol on circulation.- -The use of alcohol 

 may seriously affect the distribution of blood in the body. 

 By weakening the inhibitory impulses, the blood-vessels of 

 the skin become permanently dilated or enlarged so that a 

 large amount of blood is found in the skin. This disarranges 

 the normal adjustment of blood in the tissues. Such a 

 disarrangement is more serious in cold than warm weather 

 because it results in much loss of heat to the body. 



