Dániel Fehér, born in 1890 was university professor of botany in the western Hungarian town Sopron. He was a respected educator of generations of foresters, a renowned soil expert and an ambitious explorer of Lapland and Sahara. He became the Member of the Hungarian Academy of Sciences.

At the end of the thirties Fehér observed that the "unvisible beta- and gamma-rays" of uranium and radium cause tropic movements of plants especially of peas. Seedlings show in the dark along a definite distance negative tropism, that means the seedlings bend away the radiation source, subsequently a positive one, where they bend towards the source. The tropic effect could be described quantitatively. The dependence of the tropism conversion limits from the Intensity of the radiation, the distance of the source and the lead sheltering could be formulated.

1942 stated Fehér: "Not only elements of the close radium-, uranium-, thorium- and actinium series, and the known radioactive elements potassium, rubidium and samarium, but also the other metallic and non metallic elements" emit "a shortwave, hard, penetrating radiation". 48 elements has been investigated. Besides "inorganic" elements also the basic elements of the organic compounds: C, H, O, N, P, S proved to be radiating.

In the next years 72 elements has been recognized as radiating. The radiation, stated Fehér, is probably a shortwave penetrating electromagnetic one, wich however could not be detected in any physical way. Although the "biorays can only be detected by the biologic method developed by ouselves" absorbtion coefficient, bisecting thickness and wavelength are calculated. Until 1948 C, Na, Mg, S, Cl, K, Ni, As, U, later on Ar, Be, Br, Ca, Cu, I, and Mn has been investigated in this respect.

Professor Fehér was aware of the unexpectedness of its statements and checked the investigation. Experimentally he did not find possible radioactive contaminants. The secondary radiation on impact of cosmic rays seems unlike for even the most light elements show maximum activity.

What is the truth? 50 years later we applied some pattern recognition methods to analyse Fehér’s experimental data. No evident failures has been discovered. The enigma remains.