Letters Received to H.H. Barker, June 18, 1931

JUN 22 1931 UNIVERSITY OF MISSOURI COLUMBIA DEPARTMENT OF CHEMISTRY June 18th, 1931. Mr. H. H. Barker United States Radium Corporation 535 Pearl Street New York City, New York My dear Barker: The student, Mr. Horace Thomas, is continuing his experiments of administering radium to a group of eight or ten rats. He is staying here all summer, or a good share of it anyhow, to complete the first series of these experi- ments. We had expected that some of the rats would succumb to the radium doses which they have received. Two of the rats have been given a total of 30 mierograms, injected in- travenously, but they are still thriving and apparently the expected anemia is only very slight. It looks as if we would have to kill one or two of the rats in order to get some definite information regarding the amount of radium they a c- tually contain; and in this way get a calibration of our Wulff gama ray electroscope, which we are using to measure the activity of the rats. Of course, we can not get expired air tests on these small animals, or at least we have not yet made an attempt to do so. We need about 20 more 5-microgram ampoules to continue the experiments a step or two farther. Let me suggest that you send a copy of your criticism to Dr. Leake's report as well as a copy of the re- port to Dr. Lind, as presented at the meeting of the American Medical Association, for his information and suggestions. Under separate cover I am sending you a few samples of phosphorescent zine sulfide which Mr. William J. Byler prepared during the past year. Sincerely yours, Herman Schlundt Herman Schlundt. hs.as