Infra-Red Absorption of the N-H Bond.

A more detailed account of this work is being prepared for publication. 1 For some years investigations of the relations of environment to plant disease have been in progress at the University of Wisconsin (see Jones, L. R., "The Relation of Environment to Disease in Plants," Amer. J. Bot., 11, 601-609 (1924)). The present paper treats of a disease which affects only certain aerial parts of the host plant, and deals primarily with the relations of the aerial environment to the development and prevention of this disease. Acknowledgments are made to Dr. Leon K. Jones as collaborator in much of the work herein discussed. 2 An account of Dr. Dickson's apparatus will appear in a forth-coming Research Bulletin of the Wisconsin Agricultural Experiment Station. 3Johnson, J., "The Relation of Air Temperature to Certain Plant Diseases," Phytopathology, 11, 446-458 (1921).