Early in 1923, the U. S. Public Health Service worked out a plan for obtaining more facts than have been heretofore available concerning the common cold. Blank forms were furnished to some 13,000 persons in eleven different localities from Massachusetts to California. Each one of these persons was expected to report every two weeks as to whether or not lie had had a cold; and to supply at the same time information concerning the climate of his locality, whether or not he had been exposed to dampness or changes of temperature, the type of...
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