Letters Received to H.H. Barker, December 7, 1928

UNIVERSITY OF MISSOURI COLUMBIA DEPARTMENT OF CHEMISTRY December 7, 1928 Mr. H. H. Barker 346 Bdchmond Avenue South Orange, New Jersey My dear Howard: Let me give you a little diversion by sending you a brief account of a series of experiments which I began during the Thanksgiving Holidays and which are still awaiting completion. The experiments, however, have progressed far enough to merit report. On Friday, November 30, I commenced an experiment on my- self to extend our investigation on detecting and estimating radium in living persons. Having on hand a good supply of Mr. Bailey's Radiothor, I made use of it to get some first hand data on the elimination of the radioactive sub- stances contained therein. This water, you know, contains about 1.1 micro- grams radium element, and 1.4 micrograms mesothorium and radiothorium, a total of about 2.5 micrograms per bottle. On Friday, November 30, I drank one bottle of this water and followed it on Saturday by another bottle. Then during the Friday, Saturday, Sunday and Monday that followed, the expired air was tested at various times for radon and thoron. Excreta were collected on Sunday and Monday. These were incinerated and the residue are being used for determining radium and mesothorium content. Unfortunately, gamma ray mea- surements were not begun until Sunday afternoon at which time 1.3 micrograms of the radium element had already been eliminated. I now propose to conduct another series of experiments in which gamma ray measurements and expired air tests will be conducted parallel. Let me state briefly here some of the outstanding points of the experiment. 1. Thorium emanation was not detected at any time in the expired air. I interpret this to indicate that Thorium X, the parent of Thorium emanation was precinitated with its isotopes, mesothorium and radium, and so did not get into the Circulatory System. 8. Radon was detected in the expired air in from five to ten minutes after drinking the water and for a good many hours afterwards. In the first series of experiments after 11 hours the radon present per liter of expired air was 2.6 x 10-10 curies, whose radium equivalent would be between 20 and 25 micrograms. We interpret this to mean that the high radon content of the expired air simply represents a part of the radon which has accumulated in the water as a result of its radium content. After the lanse of two days after the second bottle of radiothor was drunk, radium emanation was no longer detected in the expired air and I infer from this that the radon dissolved in the water finds its way into the Circulatory System but that the radioactive substances, radium, mesothorium, radiothorium, and thorium X, do not get into the Circulatory System in detectible amounts.