[Skip to Content]
[Skip to Content Landing]
March 19, 1932


JAMA. 1932;98(12):1004-1005. doi:10.1001/jama.1932.02730380072024

This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.


The Reflection of Ultraviolet Rays by Mirrors  J. Cluzet and T. Kofman, in a communication presented to the Société de biologie of Lyons, showed by means of the cadmium photo-electric cell that ultraviolet rays under 3,000 angstroms behave with metallic mirrors exactly like ordinary light. The slight differences in the frankness of the images produced by these mirrors correspond to important differences in the quantity of ultraviolet rays reflected. Glass mirrors, whether backed with a silver coating or not, are much inferior as reflectors of ultraviolet rays to metallic mirrors. With a glass 1 mm. thick, only the anterior surface reflects ultraviolet rays, all that part of the cone of rays that penetrates the glass being entirely absorbed. From two points of view, these results are applicable to actinotherapy. It would be advisable, in order to improve considerably the output of ultraviolet ray apparatus, to employ as reflectors genuine metallic