that large unit when it came into action. Meanwhile, I was assigned as to Oak Ridge, I was sent to Oak Ridge, because Arnold requested, the Oak Ridge people requested, that I work there. They needed somebody to do animal work that might have some application to man. So, I was on extended duty, as they said in the Public Health Service, assigned to Oak Ridge. I stayed there for two years; then I felt to stay in this business I had to see what happens to man. So I asked to go to San Francisco, to Dr. Stone's place. He said he was willing to accept me to observe what happened in therapy. And after I was there for a very short time, Dr. Stone suggested that I ought to go through a residency in radiation therapy while I was there to become,in fact, a therapist. That would be the mostefficient way of doing it. The Public Health Service consented becausetheir facilities were not yet ready. SoI did that. And when Dr. Stone opened his laboratory in '51 or '52, he asked me to move over there when myresidency wasfinished, and dothe radiation biology for him. Because the Public Health Service wasstill not ready, I resigned. I think that's the way it went. Let's see. Yeah, I resigned,it's right here. In °53, I resigned from the Public Health Service and went into the University of California at San Francisco. BERGE: Can you describe a little bit what kind of work you were doing with animals in Oak Ridge? KOHN: I told you. We were making a study of the chemical changes in the blood of the rats following radiation. BERGE Oh, so it wasstill the same thing. 30