Spectrographic tests involve, of course, burning the substance and capturing the light on a photographic plate to determine what metallic ions are present. This was done by our spectrographic section, and again the paper of Commission Exhibit 677, the paper sample, secured November 22, was found to be similar spectrographically to the paper of the sack, Commission Exhibit 142.
Now, these were additional tests, the original examinations, under visual and ultraviolet light were made by me on November 23, 1963. Fiber analysis and the spectrographic examination were conducted on March 25, 1964.
Mr. Eisenberg. Have you now reviewed all the points in which you compared the paper sack obtained from the TSBD, Exhibit 142, and the known sample obtained on November 22, Exhibit 677?
Mr. Cadigan. Yes.
Mr. Eisenberg. Did you find any points of nonidentity?
Mr. Cadigan. No; I found none.
Mr. Eisenberg. They were identical on every point on which you measured them?
Mr. Cadigan. Yes.
Mr. Eisenberg. Mr. Cadigan, did you notice when you looked at the bag whether there were—that is the bag found on the sixth floor, Exhibit 142—whether it had any bulges or unusual creases?
Mr. Cadigan. I was also requested at that time to examine the bag to determine if there were any significant markings or scratches or abrasions or anything by which it could be associated with the rifle, Commission Exhibit 139, that is, could I find any markings that I could tie to that rifle.