Letters Received to H.H. Barker, April 2, 1932

UNIVERSITY OF MINNESOTA SCHOOL OF CHEMISTRY MINNEAPOLIS April 2, 1932 OFFICE OF THE DEAN APR / 1932 Mr. H. H. Barker U. S. Radium Corporation 55 Pearl Street New York, N. Y. Dear Barker: I expect to have occasion in the near future to apply phosphorescent zinc sulfide to a glass surface. Would you please give me the formula of the mixture I ought to make up? No radium will be used in it as it is to be used as an indicator for external alpha radiation from an alpha ray bulb which is to be used for lecture demonstrations. I had thought that I would like to mix the phosphorescent zinc sulfide together with a small amount of binder together with some other liquid which would evaporate readily. If this is feasible, please specify the amount and kind of binder and sug- gest an organic carrier. I have just noticed in the paper the warning of Flinn about the drink- ing of radium water which has caused the death of E. M. Byers of Pittsburgh. What is your opinion of the drinking of water charged with emanation? Do you believe that to be dangerous also? With best regards, Sincerely yours, S. C Lind S. C. Lind, Director. scl:en