It has always been a query in the minds of the homoeopaths and scientists, what actually happens when the magical strokes given to the dilutions of the homoeopathic medicines during the process of potentization. The latent inherent curative powers of the drugs are aroused and increased by the methods of potentization, the crucial stage of which are succussions and trituration. We have carried out a fundamental research on the effect of succussions during the process of potentisation by analysing the Mercurious Solubilis 200 under the high resolution transmission electron microscopy (HRTEM). The observations recorded in two different steps i.e. first “without succussion” and then “with succussions”. Microstructural features associated with the 10 stroked sample of Mercurious Solubilis 200 diluted with alcohol in the ratio 1:99 were observed under the HRTEM operated at 300KV and it was found that at different magnifications depict the presence of very fine particles agglomerated in a particular manner. Majority of the particles are found to have circular/round shape particles whose size varying between 3nm to 15nm. Variation in size and shape of these particles have taken place due to the strokes applied on the diluted solution of Mercurious Solubilis 200 as per specified method of homeopathy procedure. High density of nano sized particles observed for Mercurious Solubilis 200 after the 10 stroke is expected to be the reason of high potency of the drug and quick response to disease as experienced by the homoeopathic practitioners.