Кильнер:
The discovery of a screen making the aura visible was by no means accidental. After reading about the action of the N rays upon phosphorescent sulphide of calcium, the writer was for a long time experimenting upon mechanical forces of certain bodily emanations, and had come to the conclusion, whether rightly or wrongly, that he had detected two forces besides heat that could act upon his needles, and that these forces were situated in the infra-red portion of the spectrum. There was a hitch in his experiments; and in the early part of 1908, he thought certain dyes might help him. After considering their different spectra and, as far as he could, ascertaining their properties, he made a trial of several, and fixed upon the coal tar dye "Dicyanin," as the most likely to be useful. While waiting for this chemical, a thought flashed across his mind that the substance might make some portion of the effects of the above forces visible; and should this be the case, he expected to see the human aura. He had heard about that phenomenon, but until that moment never had any intention of investigating it, as he believed it to be far beyond his natural powers.