This work addresses the most puzzling question of Homoeopathy: wherein lies the (clinically undeniable) medicinal value of substances potentised beyond Avogadro limit.It attempts to find the scientific basis of homoeopathy– logically, theoretically and experimentally.First, a theoretical model of ‘induced structure'' is arrived at as a logical compulsion from a close analysis of properties of water. Then, an analysis is done for a simplified model, which hints at dielectric dispersion spectrum as the likely key to identify potentised substances and finally, an experimental arrangement is devised for this study, which gives spectral signatures of medicines. MATLAB analysis supports the concept. Results suggest that a medicine may be identified by its characteristic resonance- frequency-set. This work is expected to solve the two century old mystery of Homoeopathy and thereby silence the advocates of placebo-cure hypothesis. It will be useful for researchers in homoeopathy and for inquisitive minds who really want a scientific explanation of medicinal value of potentised substances and consequent success of homoeopathic system of medicine.