Letters Sent to Dr. Herman Schlundt, January 29, 1929

January 29th,1929. Dr. Herman Schlundt, University of Missouri, Columbia, Mo. Dear Dr. Schlundt: Mr. Eilert, of the Vitalray Radium Corporation of America, left with me last week one of the packs used in his pads, which he stated was supposed to contain 10 micrograns of radium element. These packs were made up of material where the ratio of radium to zinc sulphide was 450 micrograms to 90 grans. lie first conducted a gamma ray test with the pack and indications were that it contained approximately five micrograns, after which we ignited and found the net of the residue to be 1.2 grams. Inasmuch as Hr. Eilert should have had 2 grams of zine sulphide for the pack to contain 10 micgograms I was more or less inclined to feel that the gamma ray readings were essentially correct - however, we proceeded with an emanation determination on the residue, and found the total radium content of the pack, by this method, to be 4.4 micrograms. I thought you would be interested in this information in connection with the work which you are doing on the analysis of Mr. Eilert's pads. Sincerely yours, HHBarkersRE