52 DUST AND ITS DANGERS. 



more persistent protean catarrhs with which 

 so many persons otherwise healthy are bur- 

 dened. 



Then again dust may produce much distress 

 when not inhaled, by irritating the eyes to such 

 a degree as to cause great discomfort, if not 

 positive disease. 



The pernicious and noxious elevated rail- 

 roads have brought some parts of New York 

 into a condition very much akin to certain 

 coal mines, with the large amounts of dust and 

 fine cinders which they shower down upon the 

 streets and into the adjacent houses and into 

 the eyes and lungs of the pitiable citizens 

 of this metropolis. 



As to the bacteria about which our main in- 

 terest centres, there are unfortunately a few 

 species which, when they once find lodgement 

 in one place or another in the organs of 

 respiration, may grow and multiply, and .suc- 

 cessfully resisting all the protective agencies of 

 the body, set up distinct, persistent and even 

 fatal disease. Those forms of bacteria which 

 can or in these regions commonly do this, are 

 insignificant in number in comparison with the 



