Review of Saamanya Shodhan (Common Purification) of Metals (Dhatus)
Jyoti Brijesh Gavali
Journal Title:International Journal of Ayurveda and Pharmaceutical Chemistry
Metals are in use as medicines since centuries. These metals have to undergo various types of processing before it is used in medicines. One of these processes is saamanya shodhana (common method of purificationwhere the thin (kantakvedhi) sheets of metals are subjected to heat and immediately quenched in different organic liquid media. This method is common to all the metals like gold, silver, copper, iron, tin, zinc, lead, and alloys like brass and bronze. In this process thin sheets of metals are heated and quenched in different liquid media for a specific number of times repeatedly. This introduces the organic properties in the metals as well as reduces its particle size and reduces/removes toxic properties from the metals. The effect of this is that microcracks develop in the metal, and the metal loses its physical properties of malleability and ductility. Toxic properties if any are reduced to the minimum (tolerable). In summation the shodhana causes reduction in particle size, introduction of organic elements, removes impurities and reduces toxicity of the metals. The different liquid media are variable in nature and components. Micro fractures are caused on the surface of the metals due to imbalance in the tension and compression forces. Depth and size of these fractures depend on the tensile stress, stress concentration, temperature, and surface energy according to fracture mechanics (Griffith’s theory). Difference in nature of the fluids may cause addition to the stress. These factors cause particle size reduction of the metals.