VI. CONCLUSION These measurements confirm the interest in radon as a tracer for atmospheric physics. The resuits shown cannot yet be extended to give a total quantitative interpretation. We are continuing these studies so as to develop a qualitative interpretation. In particular the resolution of the Fick diffusion equation for a non-homogerecus emanation from the soil would allow using radon for the study of atmospheric diffusion in the troposphere. BIBLIOGRAPHY (1) WEXLER (H.) et al. 1956, Atomic Energy and Meteorology Proc. of. The Intern. (2) KIRICHENKO (L. V.) : Problems of Nuclear Meteorology, 92, 124, Moscou 1962. (3) WILKENING (M. H.) : Amer. Geophys. Union. Transact., 37, N2, 1956. (4) WILKENING (M. H.) : Radon Sampling Technique for Study of Orographie Cumuli, (5) JACOBI (W.) and ANDRE (K.) : Journ. of Geophys. Res., 68, 13, 3799, 1963. (6) MACHTA (L.) and BOUVILLE (A.) : Congres de la S. F. R. P., Mars 1967, sous presse. Conf. on the Peaceful Uses of Atomic Energy Geneve 13, 333, 334- a paraitre. _7-