FLOWERS IN THE SICKROOM

To the Editor: —InThe Journal, Dec. 5, 1931, page 1731, Dr. Stein asked why flowers are removed from the sickroom at night. In your answer you say: "The statement of one hospital superintendent that carbon dioxide is liberated is apparently not correct. Living plants absorb carbon dioxide and give off oxygen." True enough, but this absorption of carbon dioxide stops in the dark, and cell respiration continues. Respiration is going on continually, in light and in darkness, and carbon dioxide is given off. It isn't true that the processes of giving off carbon dioxide and oxygen are reversed. Carbon dioxide is given off day and night, the rate being but little higher during the day or in the light than it is in darkness or at night. It varies somewhat more with change in temperature, increasing up to 40 C. Weight for weight, plants give off about the same