Mercury poisoning is a disease caused by exposure to mercury or its compounds. Mercury is the working fluid in the mercury vapor turbine. Chelation therapy is an antidote for poisoning by mercury, arsenic, and lead. Research on the treatment of mercury poisoning is limited. Only DMSA is FDA-approved for use in children for treating mercury poisoning. These had a bob consisting of a container of the liquid metal mercury. Poisonings due to consumption of seeds treated with mercury compounds are sometimes misidentified as ergotism. These deposits also have trace quantities of gold and mercury. Transits of Mercury and Venus have been observed from Mars. Its mass is roughly half that of the planet Mercury. This is similar to the crustal abundance of silver, bismuth and mercury. The 1958 Edsels were assembled in both Mercury and Ford factories. Size is the best predictor of increased levels of accumulated mercury. Ganymedian craters are flatter than those on the Moon and Mercury. This is between the orbits of Mercury and Venus.