Mr. Eisenberg.

I will now hand you a sketch which was made by a participant in those tests, which shows the distribution of the blue or violet dots which constitute a positive reaction to this test on the left and right hands of Lee Harvey Oswald.

Representative Boggs.

Before you do that, Mr. Cunningham, will you describe briefly the procedure on a paraffin test? I want to understand exactly what it is.

Mr. Cunningham.

The so-called paraffin test is the making of reinforced paraffin casts, of a person's hands, and then treating either with either one of two reagents. One is diphenylamine, and the other is diphenylbenzidine.

Representative Boggs.

Is that when the cast is on?

Mr. Cunningham.

That is definitely after it is removed.

Representative Ford.

You actually make a cast of the individual's hand?

Mr. Cunningham.

Oh, yes.

Representative Boggs.

You make the casts. Then you take the casts off.

Mr. Cunningham.

You slit it.

Mr. Eisenberg.

Can you describe how the cast is made?

Mr. Cunningham.

Yes. You first take warm paraffin. Each paraffin melts at a slightly different temperature. What we were using in our tests melts at about 130°. And this hot paraffin is placed on the hands. It is spread on with a brush, or it can be poured over. If you are sure that your brush is absolutely Clean and will not react--and we checked all of our equipment so that we were not getting a reaction from the diphenylbenzidine we let it pour on from the brush. Once you get a coating, you can just brush it on, because then you won't be disturbing any materials on the hands. And after you get a coat on, you take gauze bandages and lay them on top and put more paraffin on them. The gauze does nothing more than to give it reinforcement so it won't fall apart or crumble when it gets real cool. Then you cut them off the hands after they cool. Then they are chemically processed with either diphenylamine or diphenylbenzidine.

Representative Boggs.

The cast?

Mr. Cunningham.

Yes; the portion of the cast next to the hand.

Representative Boggs.

Right. I understand now.

Mr. Eisenberg.

Can you explain why paraffin is used? What is the action of the paraffin?

Mr. Cunningham.

Well, the warm paraffin has the effect of opening up the pores of the skin and many times material that you cannot get off from washing will be picked up in the sticky paraffin. As it is cooling, the dirt and the foreign material on the hands will become embedded in the paraffin.

Mr. Eisenberg.

So the paraffin acts as a base to pick up--

Mr. Cunningham.

It acts as a medium in which the foreign material is picked up from the hands.

Mr. Eisenberg.

When you add the reagent, what is considered to be a positive reaction?

Mr. Cunningham.

It turns a blue color.

Mr. Eisenberg.

That is the cast? When you say "it," it is the cast?

Mr. Cunningham.

Well, specks on the cast.

Mr. Eisenberg.

Dots?

Mr. Cunningham.

Yes, or an area of the cast. The theory of the test is that it is a test for gunpowder residues. Now, that is the theory, and it is fallacious, inasmuch as the reagents used in these two tests are not specific for gunpowder residues. Now, it is true that the nitrates and nitrites in gunpowder residues will react positively with diphenylamine and diphenylbenzidine, but they are not specific. They will react--these two reagents will react with most oxidizing agents.

Mr. Eisenberg.

Can you give us a few examples?

Mr. Cunningham.

Yes. Urine, tobacco, cosmetics, pharmaceuticals, soil, fertilizer--I have a list here of the different families or classes of compounds that will react.
In addition to nitrates and nitrites, substances such as dichromates, permanganates, hypochlorites, periodates, some oxides, such as selenium dioxide and so forth. Also, ferric chloride and chromates and chlorates. The list of