26 DUST AND ITS DANGERS. 



which settled from the floating dust on to the 

 bottom of a round dish about 3f inches in 

 diameter in different places in New York was 

 as follows : 



1. Central Park. Dust blowing from an 

 adjacent street, 499. 



2. Union Square, 214. 



3. Private house, 34. 



4. Large retail dry goods store, 199. 



5. Broadway and 35th Street, 941. 



6. Street in the process of being cleaned, by 

 the Street-Cleaning Department, 5,810. 



A sufficient explanation of the number of 

 germs in the air at the lower part of Central 

 Park is found in the westerly wind and the ex- 

 tremely filthy condition of the streets on the 

 windward side. The result of the analysis 

 shown in fig. 6, needs no lengthy comment. 

 That as many living germs as of colonies 

 which are here seen growing should be float- 

 ing in the air and liable to be breathed in by 

 any unfortunate passer-by within five minutes, 

 is evidence enough of the filthiness of the 

 practices of so-called street-cleaning. As to 

 its danger, more by and by. 



