This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
THC .. D. C. Bardwell Study of Nitrogen Fixation.tif Photograph unknown en Bardwell inspecting the mechanism for study of nitrogen fixation by alpha rays completed at the Fixed Nitrogen Research Laboratory depicted people Bardwell depicted place Fixed Nitrogen Research Laboratory Print Photographic Original Negative in Institution