THE CIRCULATION 69 



serum of the blood also destroys the germs by the antitoxins in it. 

 Inflammatory troubles are : colds, rheumatism, diarrhoea, and all dis- 

 eases with name ending "#/>." An inflamed part is red, swollen, hot, 

 and painful. 



Prevention and Care of Colds. A cold is an inflammation of a 

 mucous membrane. Colds are prevented by so living as to encourage 

 a/r<?<?, vigorous circulation, and especially by not coddling the body so 

 tenderly that the circulation becomes deranged by the least exposure. 

 The circulation may be deranged by overheating as well as by chilling 

 the body ; usually it would be more appropriate to say that the person 

 caught " a hot " than * a cold." At the first sign of a cold vigorous 

 exercise, a cold bath, or going outdoors into cold air may aid in sending 

 fresh blood to remove the stagnation and stop the inflammation. A 

 warm foot bath and hot drinks may relieve by drawing blood from the 

 congested mucous membrane. After the cold has become fixed such 

 measures will not help, but the cure is aided by helping the skin to 

 keep its full share of blood. The cold must run its course. The cells 

 will be given every chance to repair the injury and destroy the germs 

 (if any) by avoiding hard work, eating moderately of digestible food, 

 avoiding drugs, especially infallible drugs advertised in newspapers, 

 even if recommended by otherwise intelligent people. Repeated colds 

 tend to become a disgusting disease called chronic catarrh. Con- 

 stricting the blood vessels of the skin causes congestion of the (internal) 

 mucous membranes. A skin tenderly protected constricts more readily 

 than one accustomed to cold. Cold is the best preventive of cold. Cold 

 baths, pure air, light clothing, free breathing, moderate eating, ward off 

 colds. Fussing with sprays, gargles, and drugs will not; for the 

 main factor in bringing on a cold is not germs, nor temperature, but the 

 state of the system itself. Persons who have suffered much with colds 

 have found that after substituting cotton underwear for woolen, colds 

 became very rare. Linen will have a similar effect, but it is not as dur- 

 able, soft, or heat-retaining as cotton (see p. 16). 



PRACTICAL QUESTIONS. 1. Through what kind of skin do the 

 blue veins in the wrist show most plainly? 2. Which is more com- 

 pressible, a vein or an artery? 3. Why are those who take little exer- 

 cise likely to have cold feet? (p. 57.) 4. Where does the so-called 

 venous blood flow through an artery? 5. What vein begins and 

 ends in capillaries? (The portal vein, colored Fig. 5.) 6. To what 

 purifying organ, after leaving the lungs, does the heart send part of 

 the blood for further purification. (Colored Fig. 5.) 7. What keeps 

 the blood moving between the beats of the heart? 



