THE ETIOLOGY OF ACUTE UPPER RESPIRATORY INFECTION (COMMON COLD).

Experimental upper respiratory infections similar to "common colds" were transmitted singly and in series through two and four passages in nine out of fifteen persons, by intransal inoculations with bacteria-free filtrates of nasopharyngeal washings obtained from individuals ill with natural "colds." These observations conform with those reported by previous workers and lend further support to the view that the incitant of the "common cold" is a filtrable virus.