Mr. Redlich. In your opinion, would the washing of these paraffin casts remove substantial amounts of the elements barium and antimony if they were present on those casts?
Mr. Gallagher. Chemical treatment and washing will remove portions of the barium and antimony from these casts. This was determined from test casts which were studied in connection with these analyses. But it did not remove all the barium and antimony.
Mr. Redlich. Can you describe exactly what you did with these paraffin casts in order to perform a neutron activation analysis?
Mr. Gallagher. Do you want me to tell who I worked with here?
Mr. Redlich. Yes.
Mr. Gallagher. These casts were taken to the Oak Ridge National Laboratory at Oak Ridge, Tenn., and there, with a Dr. Frank F. Dyer, and Mr. J. F. Emery, work was performed on these casts. The casts were studied under a binocular microscope. The surface of the casts were scraped. These paraffin scrapings were put into a small container which was then placed in a pneumatic tube and sent into the heart of the research reactor to be bombarded by neutrons for a 3-minute period. The neutron flux was 6 times 10 to the 13th neutrons per square centimeter per second. After the 3 minutes were up, the container with its contents was discharged from the reactor.
The gamma ray spectrum was studied. And then chemical tests were made to precipitate barium and also to precipitate the antimony. The barium and antimony were quantitatively determined.
Mr. Redlich. You stated in your answer that——
Mr. Gallagher. Correction. Were quantitatively determined by studying the gamma rays emitted by the barium isotope 139 and the antimony isotope 122.
Mr. Redlich. Now, according to your testimony, you determined that the elements barium and antimony were present in the hand casts in an amount greater than would be expected in the case of a person who had not fired a revolver.