In 1872 Dr. O'Dwyer was appointed to the staff of the New York Foundling Asylum, in connection with which his real life-work was to be accomplished. While there Doctors Reynolds and J. Lewis Smith were his colleagues, and all three of them have added no little distinction to American medicine by the careful observations made at that asylum. At this time one of the most fearful scourges that could afflict a foundling asylum or children's hospital was an epidemic of diphtheria. Those who pretend not to believe {329} in the efficacy of the antitoxin treatment of diphtheria should listen to the account given by some of the Sisters, who for long years were in service in the New York Foundling Asylum, of the fear that came over them when it was announced that diphtheria had entered the wards in their charge. It was always certain beyond doubt that this disease would spread very extensively, and, in spite of all precautions and the enforcement of whatever quarantine was possible, the mortality rate would be very high. Usually forty or fifty per cent, of those who were attacked by diphtheria would perish from the disease, nor was it easy to foresee the end of any epidemic. In not a few cases death took place from that most excruciating of all fatal terminations--asphyxia. The false membrane, characteristic of diphtheria, would form, in a certain proportion of cases, in the larynx and upper part of the trachea of the little patient, the inflammatory swelling that accompanied it further decreasing the naturally small lumen of the child's undeveloped air passages. Gradually dyspnoea would set in, the dreaded croup begin to be heard, and difficulty of breathing developed at times to such a degree that the little one would use every effort to secure breath, the aeration of the blood growing less and less, and cyanosis--that is, an intense blueness of the face and hands--becoming evident, till finally the child died slowly in all the agonies of asphyxiation, while doctor and nurse stood sadly by, absolutely powerless to do anything to relieve the heart-rending symptoms. About the middle of the nineteenth century tracheotomy--that is, the surgical opening of the trachea, or wind-pipe, below the larynx, for the purpose of admitting air to the lungs through such artificial opening--had been introduced by Trousseau, of Paris. In many cases this afforded relief; {330} at least the little patients did not die the awful death by asphyxiation, though not many recovered from the diphtheria or the results of the operation. O'Dwyer himself, when asked what had led him to think of intubating the larynx, said that he had been aroused to experimentation in this direction by the complete failure of tracheotomy during the years from 1873 to 1880 at the New York Foundling Asylum.