bacteria: 
front of her. 
. Classroom experiment in Haaren High School, New York City, 
Pupil at table, who has coughed vigorously, has Petri dishes exposed at equal distances apart on tables in 
Petri dishes with sterile agar supplied by Brooklyn Botanic Garden. March 6, 1928. (6483.) 
to show the effect of a cough carrying 
