612 MAN AS A CONQUEROR 



decades ago, interest centered in civic clean-ups because it was 

 believed that clean streets meant a lower death rate, but street 

 cleaning or house cleaning will not control epidemics of disease. On 

 the other hand, there are unfavorable environmental factors which 

 directly contribute to outbreaks of epidemics, such as impure milk 

 and polluted water supply, the control of which is of the utmost 

 importance to the health of the individual. Not only food supplies 

 containing the proper vitamins necessary to life are essential to 

 health, but also the assurance that all foods handled are clean and that 

 the handlers of foods are also clean and free from disease. Selfishness 

 of neighbors is a large factor in the health of a given community, 

 since communicable diseases are spread through carelessness on the 

 part of those who have them. The publicity of scientific knowledge is 

 a large factor in public health. The increase of interest on the part of 

 the public is today correlated with clinics for the care of babies, for 

 prenatal care, for the care of venereal disease and tuberculosis, and 

 above all with clinics where treatment for immunity against certain 

 diseases may be received. Health knowledge disseminated by means 

 of bulletins, lecture bureaus, radio talks, and particularly school 

 health programs and public nursing services, are all factors which 

 help to control unfavorable conditions in a given community. 



Degenerative Diseases 



After the age of forty, the greatest numlier of deaths are caused by 

 heart disease, cerebral hemorrhage, arteriosclerosis, cancer, paresis, 

 and nephritis. Along with these, pneumonia and tuberculosis claim 

 many victims. The statistician, Louis Dublin, states that approxi- 

 mately 2 per cent of the total population of the United States suffer 

 from organic heart defects and that the number of deaths from this 

 cause is over 200,000 annually. It is the chief cause of death after 

 the age of forty-five years. The origins of this disease often date 

 back to childhood, when heart lesions may have resulted from early 

 infections. A large percentage of heart trouble is also due to syphilis. 

 In the case of cancer there is a constantly mounting mortality. We 

 know what cancer is, but we do not know what causes it. Apparently 

 certain groups of cells go wild, growing without restraint until they 

 destroy their victim. Two types of cancer are knowm, only one of 

 which is malignant. Education ought to make people realize the 

 necessity of immediate diagnosis and an operation, when necessary, if 

 cancer is to be overcome. Nephritis, a disease of the kidneys, slows 



