With the increasing use of the ultraviolet light as an important therapeutic measure for children, it is obviously necessary to ascertain the effect of this procedure on the young organism. In the first paper of this series, it was shown that the ultraviolet light was capable of increasing the blood platelets in the new-born infant.1 The second paper dealt with the erythrocytes and hemoglobin.2
This study is based on the observations on a series of 120 new-born infants during a period of ten months. The total white cell count and the differential count were made within six hours after birth, and at twenty-four hour intervals thereafter. The determinations were made at the same time every day.Treatments with the ultraviolet rays were begun on alternate infants on the second day, and continued thereafter at the same time on each of the following four days.