352 ANNALS NEW YORK ACADEMY OF SCIENCES 



Summary of Papers. 



C.-E. A. Winslow and I. S. Kligler in their paper presented the re- 

 sults of the examination of about 170 samples of dust from streets, 

 schools, houses and public buildings in New York. The total numbers 

 of bacteria found varied from 150,000 per gram to 145,000,000, aver- 

 aging from 3,000,000 to 5,000,000 from the indoor dusts and 49,000,000 

 from the street dust. Spores made up usually less than one-tenth of 

 the total. The count obtained at body temperature was about one-half 

 that at room temperature, averaging from 2,000,000 to 3,000,000 per 

 gram in the indoor dusts and 22,000,000 in the street dusts. B. coli 

 was usually present; in the street dust an average of 51,000 per gram 

 was found and in two samples over 100,000, while none showed less 

 than 100. The indoor dust, on the other hand, showed an average of 

 between 1,000 and 2,000. Acid-forming streptococci, such as are char- 

 acteristic of the mouth, were present to the extent of over 1,000 per 

 gram in three-fourths of the street samples and one-half of the indoor 

 samples. The average for the street samples was about 40,000 per 

 gram ; for the indoor samples about 20,000 per gram. The large pro- 

 portion of these organisms, particularly in the indoor dusts, appears to 

 be significant of buccal pollution. 



The paper, which was illustrated by charts and diagrams, was dis- 

 cussed by Dr. Lucas. 



Dr. Chapin said in abstract : The diffusion of contagion through the 

 room or out-of-doors only was considered, not droplet infection, which 

 does not take place beyond a meter. Bacteriological evidence was not 

 discussed, though the quantitative work of Winslow on sewer air and 

 spray infection was referred to, a work which he is now extending to 

 dust. Epidemiological study and experiment have been rapidly nar- 

 rowing the list of alleged air-borne diseases. We now know that yellow 

 fever and malaria are never air-borne; experiments have shown that 

 bubonic plague and Mediterranean fever are not. There is no evidence 

 that cholera and typhoid fever are ever air-borne and much that they 

 are not. The spread of influenza out-of-doors does not take place, and 

 perhaps not indoors. The alleged evidence that smallpox virus is air- 

 borne around hospitals is very weak. Careful observation in hospitals 

 has shown that typhus fever, cerebro-spinal meningitis and poliomye- 

 letis do not pass from patient to patient in the same ward. The same 

 is true for uncomplicated scarlet fever and for diphtheria except by con- 

 tact or close droplet infection. Probably measles and whooping cough, 

 rubella, mumps, chickenpox and smallpox are not air-borne, even in the 



