419 



in isolation in tlie country. Many conditions are so extreme that ttio 

 reader has no difficulty in determining where a mention applies : pure 

 food, contaminated food; good water, polluted water; pure air, impure 

 air ; smog clouds overhead, Ijlue sky overhead. 



Crowding, food, water have all for a long time received attention and 

 great efforts have been made to improve conditions. But not until re- 

 cently have air conditions beea given attention. Black smoke clouds re- 

 ceive fre<iuent mention in the public press. The dust problem is liliewise 

 receiving more and more attention — if the people knew to what extent it 

 is a factor in producing ill health ai'd disease and death they would soon 

 make a determined effort to alter existing conditions. 



What are the effects on a pure air man when he goes into the large 

 and dirty city overhung with smog clouds? Dust makes him feel dirty. 

 his hands and clothing are soiled; he "blows black" into his handker- 

 chief and spits black ; there is more or less free production of mucus, 

 followed perhaps by pus formation, and he will speak of having catarrh ; 

 in attempting to hawk up morning phlegm he may become nauseated and 

 even vomit ; dust particles reach his lungs and become imbedded, the lung 

 becomes black (in old city residents it is coal black, pneumokoniosis) ; 

 he experiences all sorts of disagreeable sensations, symptoms of ill health 

 .so-called, symptoms shade off into affections, minor maladies and disease ; 

 infective particles are locked up in the lymphatics, forming "kernels" in 

 the neck and tumors along the windpipe and in the lungs and these burst- 

 ing proiluce disease and death. The two great dust diseases are tuber- 

 culosis and pneumonia, they decimate mankind by thousands and millions. 



^ledical men have names for the effects produced by the inhalation 

 of different forms of dust : Anthracosis for the effects produced especially 

 ill coal miners; Byssinosis due to inhaling cotton dust, as in cotton fac- 

 tories ; Clialicosls, Silicosis and Siderosis are names applied to affections 

 in potters, stone masons and iron workers who inhale gritty matter. The 

 term Pollenosis is expressive and should come into general use ; the name 

 indicates a state or condition produced Vty inhaling pollen, that is in those 

 susceptible. 



Kinds of Dust\ — There are all kinds of dust, all of varying impor- 

 tance in the welfare of man. To the iiliyslci.st dust is of great importance 

 in the matter of light and shade and precipitation; to the tidy house- 



1 For a synoptical table of Kinds of Dust an relationship to stages of civiliza- 

 tion, see my Presidential .\ddress, Indiana .\cademy of Science, for 1906, p. 23. 



