Abstract :
Ultra-high dilutions of lithium chloride and sodium chloride (10−30 gcm−3) have been irradiated by X- and γ-rays at 77 K, then progressively rewarmed to room temperature. During that phase, their thermoluminescence has been studied and it was found that, despite their dilution beyond the Avogadro number, the emitted light was specific of the original salts dissolved initially.