Armstrong – Table of Contents

to check it with a “non-pathogenic” organism. He chose the bacterium Serratia
marcessans, at that time thought to be a harmless commensal germ but now known to be
highly pathogenic for humans. This particular bacterium produces a distinctive red
colony on agar bacteriologic media. He scattered open agar-containing Petri dishes in the
attic of the building. He then put a suspension of the Serratia organisms into the building
ventilation system’s intake and inspected the open Petri dishes at regular intervals. In
about 24 hours he noted that all the Petri dishes contained the distinctive red colonies of
the growing bacteria. From this observation, Armstrong concluded that the building’s
airflow control was working improperly. There was no follow through as to whether any
corrective action was ever taken.
In the mid-1950s the interior architecture of Building No. 7 changed appreciably
when the research emphasis changed to respiratory viruses and when there was an influx
of many new, young investigators. The author participated in an audio-video taping of the
interior of the building around 2003 and could hardly recognize any of the old unit
architecture. The central areas had been divided and sub-divided into multiple smaller
spaces. The animal rooms had been relocated to the basement and eliminated from the
units in order to make more working benches and cubicles. The old clothes-changing air
locks had also been subdivided and some of the included sanitary facilities eliminated,
leading to daily inconvenience for the people working in the corresponding research
units. The working areas of the units were changed the least, and the author readily
recognized features that he remembered. When the building was finally shut down, the
personnel were transferred to other sites on and off the main NIH campus.