RT Journal T1 CUrrent comment JF Journal of the American Medical Association JO Journal of the American Medical Association YR 1939 FD October 7 VO 113 IS 15 SP 1418 OP 1419 DO 10.1001/jama.1939.02800400046015 UL http://dx.doi.org/10.1001/jama.1939.02800400046015 AB OXYGEN AND CARBON DIOXIDE IN PNEUMONIA  Although oxygen has been employed in pneumonia for nearly two decades, not all of the factors concerned in its administration have been thoroughly elucidated. In an experimental investigation of this subject by Cohn and his collaborators,1 five series of experiments were performed on carefully picked dogs, embodying the determination of the normal physiologic variations in oxygenation and acid-base balance occurring in the blood of the dogs, the determination of the effect of experimental pneumonia on the oxygenation and acidbase balance of the blood, the determination of the effect of breathing air enriched with oxygen alone on normal dogs and on anoxemic dogs, the determination of the effect of the breathing of air to which carbon dioxide had been added on normal and pneumonic dogs, and the determination of the effect of breathing air enriched with both oxygen and carbon dioxide on normal and