This is the first publication, in print, of the discovery of the nature of colds, the commonest ailments of mankind, and of the only successful method of preventing or combating them that is rapidly effective. It was first presented to the medical profession at the Sixth International Congress of Otolaryngology, a distinguished group of specialists and professors in the field, from all parts of the world, at Washington, D.C., on May 10, 1957. The combined publication of a popular and a scientific version of this significant discovery has been undertaken in an effort to make available to everyone information that is essential for the preservation of health, in a readily understandable form. Its simplicity should present no difficulty to anyone who seeks either to avoid, or be rid of, a cold and is willing to make the effort to do so.