108 COMMISSION ON BUILDING DISTRICTS 



materially aids in providing resistance against diseases like tuberculosis. 

 The sun has a destructive effect upon disease breeding bacteria. Direct 

 sunlight is a most effective disinfectant. Direct daylight — even though not 

 direct sunlight has a powerful influence in destroying pathogenic bacteria. 

 In addition to that people who are able to live in well lighted apartments 

 have a physical resistance which is superior to that of people who live in 

 dark mi mis. That has been proved under exact experimentatal conditions in 

 laboratory tests and is a matter of common observation among human 

 beings. 



The morbidity of tuberculosis in the old law tenements is twenty per 

 thousand of population, and in the new law tenements it is fifteen per 

 thousand of population. The morbiditity of tuberculosis in the twenty-fifth 

 census district is ten per thousand, and for the entire city one-tenth per 

 thousand. 



It is the popular impression that all artificial light is detrimental to the 

 nervous system and causes a deterioration of nervous control ; but the 

 damage to people's individual resistance is probably a more important factor 

 than the actual damage to special senses, except where the light is obviously 

 insufficient or excessive. 



As much damage has been caused by an excessive supply of light in 

 certain places as has been by the absence of sufficient light in other places. 

 One can stand a superfluity of sunlight and benefit from it. In a room 

 where there is the same amount of light supplied by an artificial means, 

 very serious nervous disabilities result, owing to the entirely different 

 physical qualities of most artificial light. 



Effect of vegetation on humidity and temperature 



Continuous high temperature of a hot spell in the city is higher and 

 more prolonged in areas where stone or brick or concrete construction is 

 continuous, than where there are open spaces. Radiation during the night 

 does not permit of the same reduction of temperature in densely built-up 

 areas as occurs in other parts of the city where those conditions do not 

 exist. Our general experience is that most of the heat prostrations occur in 

 districts where there are few or no open spaces. 



Humidity is maintained more nearly the normal point in the vicinity 

 of open spaces where there is a vegetation. Other things being equal, the 

 temperature tends to be lower in the neighborhood of parks. 



Relation of stair climbing to health 



Excessive stair climbing and excessive standing when fatigued in 

 crowded conveyances unduly aggravate certain disabilities from which 

 women suffer. Climbing stairs is not per se any more dangerous for women 

 than for men. but the disabilities from which they commonly suffer are 

 apt to be aggravated more than the disabilities from which men suffer. 

 The class of people who suffer much more than women is the large army 

 of children with cardiac diseases, and there are 16,00(3 children in the 

 public schools of this city who have new such damage to their hearts as will 

 probably permanently handicap them. 



At least two per cent of the children in the public schools have organic 

 diseases of the heart, resulting either from infection acquired congenitally, 

 or acquired as the result of scarlet fever, tonsilitis, rheumatism, chorea, etc. 

 These children, if they live in such places as one and two family houses, 

 for instance, or premises where they have but little stair climbing to do, 

 are going to be able to adjust themselves and compensate for their physical 



