In order to explain the significance as the causative agent of Minamata disease of methyl mercury chloride which was extracted from the sludge in the reaction tube in the acetaldehyde plant of Minamata Factory and from the shellfish in the Minamata Bay, methyl mercury chloride and other methyl mercury compounds which are able to be derived from methyl mercury chloride were synthesized, and the toxicity and the chemical properties of mercury compounds accumulated in organs of animals administered with those methyl mercury compounds were observed.
