Abstract
1. The contents of the caecum and small intestine of the rat metabolized methylmercuric chloride in vitro to a volatile product over a period of 3 to 4 days. The bacterial flora of the gut were responsible for the metabolism.
2. In the presence of caecal contents methylmercury was reduced to metallic mercury.
3. The contents of the small intestine metabolized methylmercuric chloride indirectly, as a result of prior synthesis of H2S to a volatile sulphur derivative of methylmercury.