Then you examine them under a high-power comparison microscope or a binocular microscope under approximately 120 times magnification. In this particular case I used two different stains.
First a malachite green stain. This merely determines if there are any unbleached fibers, or if they are all bleached. I found that on both Commission Exhibit 677, the paper sample obtained on November 22, and the paper sack, Commission Exhibit 142, that they are almost 100 percent unbleached fibers.
Then I stained other samples, with a stain known as Herzberg stain. It is an iodine-iodide stain, which will distinguish between rag fibers, chemical wood fibers, and ground wood fibers by different coloring. The chemical wood is stained blue, rag fibers are stained red, ground wood stained yellow.
I made and studied specimens or slides of fibers from Commission Exhibit 677, the known sample, and from Commission Exhibit 142, the paper sack, to see if the fiber composition is similar. What that means is, is this chemical wood, is it coniferous or deciduous, are there any rag fibers in there or are there any ground wood fibers in there, and I found here the fiber composition was similar and essentially it is a coniferous woodlike pine. There were a few stray rag fibers, which I think were probably accidental, and a few stray ground wood fragments in there.
Mr. Dulles. Let me get clearly what is similar, that is the paper bag, Exhibit——
Mr. Cadigan. 142; the paper comprising that sack and the paper comprising the known sample obtained November 22, Exhibit 677.
Mr. Dulles. Right.
Mr. Cadigan. The papers I also found were similar in fiber composition, therefore, in addition to the visual characteristics, microscopic and UV characteristics.
Mr. Eisenberg. "UV" being ultraviolet?
Mr. Cadigan. Yes, sir. Then I had a spectrographic examination made of the paper from the sack, 142, and the known sample secured November 22, Commission Exhibit 677.