390 MAN'S IMPROVEMENT OF HIS ENVIRONMENT 



of the health board in order to find out how we may cooperate with 

 them. 



The Division of Infectious Diseases. — Infectious diseases are 

 chiefly spread through personal contact. It is the duty of a gov- 

 ernment to prevent a person having such a disease from spreading 

 it broadcast among his neighbors. This can be done by quarantine 

 or isolation of tlie person having the disease. So the board of 

 health at once isolates any case of disease which may be communi- 



Comparison of cases of illness during the summer of 1913 in two city blocks, one 

 clean and the other dirty. What are your conclusions ? 



cated from one person to another. No one save the doctor or 

 nurse should enter the room of the person quarantined. After 

 the disease has run its course, the clothing, bedding, etc., in the 

 sick room is fumigated. This is usually done by the board of 

 health. Formaldehyde in the form of candles for burning or in a 

 liquid form is a good disinfectant. In disinfecting the room should 

 be tightly closed to prevent the escape of the gas used, as the 

 object of the disinfection is to kill all the disease germs left in the 

 room. In some cases of infectious disease, as scarlet fever, it is 

 found best to isolate the patients in a hospital used for that pur- 

 pose. Examples of the most infectious diseases are measles, 

 scarlet fever, whooping cough, and diphtheria. 



Immunity. — In the prevention of germ diseases we must fight 

 the germ by attacking the parasites directly with poisons that will 

 kill them (such poisons are called germicides or disinfectants) , and 

 we must strive to make the persons coming in contact with the 

 disease unlikely to take it. This insusceptibility or immunity may 



