Mr. Redlich. You will note that this letter indicates a variety of substances which contain the element barium, the element antimony, and substances which contain the elements barium and antimony.
The last question I asked you, Mr. Gallagher, was whether you could make a judgment as to whether a person from whose hands these casts were made had fired a weapon or handled a fired weapon, and you indicated that on the basis of these tests you could make such a judgment.
The question I now ask you is in light of the contents of the letter which has been designated as Gallagher Exhibit No. 1, are you able to isolate the source of the elements barium and antimony which you found on the hand casts as coming from the primer residues rather than from the substances which are described in Gallagher Exhibit No. 1?
Mr. Gallagher. It is true that there are common commercial products which contain barium and which contain antimony.
Mr. Redlich. And which contain barium and antimony together?
Mr. Gallagher. And also which contain barium and antimony together. However, before these elements can contaminate the hands or person—hands or body of an individual—they must be accessible so they can adhere by mechanical adhesion to the individual. Under normal circumstances, most of the ingredients mentioned in Exhibit No. 1——
Mr. Redlich. Excuse me—could you refer to that as Gallagher Exhibit No. 1?
Mr. Gallagher. Gallagher Exhibit No. 1, is not normally in the form which will permit contamination by this mechanical adhesion.
Mr. Redlich. Are you generally familiar with the test which is commonly referred to as the paraffin test, which tests paraffin casts for nitrate residues?
Mr. Gallagher. Yes, sir.