Abstract
THE report of the secretary of the Smithsonian Institution for the year ended June 30, 1939, which has been published, refers to the completion by the Astrophysical Observatory of the enormous task of recomputing the daily solar constant values from all its observing stations since 1923, apart from the final corrections and general discussion, which were expected to be concluded by October 1939. The Division of Radiation and Organisms gave much attention during the year to photosynthesis, factors influencing plant growth and the stimulative action of ultra-violet radiation. Experimental evidence was obtained indicating the formation during photosynthesis of a material which combines with or absorbs carbon dioxide and resembles chlorophyll in character. A quantitative method for the isolation of hormones from plants is being developed, and the effect of radiation on the growth of excised roots and leaves has been investigated.
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Smithsonian Institution: Annual Report. Nature 145, 930 (1940). https://doi.org/10.1038/145930c0
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DOI: https://doi.org/10.1038/145930c0