Few direct observations have been made regarding the rate, rhythm and volume of respiration in premature infants. During the past year, we had the opportunity of making such studies, and in this report we desire to present the results of observations on nine infants, varying in weight from 2 pounds and 6 ounces (1,077.28 Gm.) to 5 pounds, 1 ounce (2,296.31 Gm.).
The apparatus that we used is so arranged that the body of the infant could be placed in a cylindric brass tube, with a transparent celluloid window in the upper surface to permit observation. The tube was closed at one end, and with the infant's head resting comfortably on a small pillow, the opposite end was closed by fitting a rubber dam snugly about the neck. The cylinder containing the infant's body was then connected to a Krogh spirometer with its writing point in contact with a