This malefactor had been purser on board his majesty's ship Amphitrite, and from some unsuccessful speculations had got himself into embarrassed circumstances. In 1809 he entered into a concern, with some others, to ship goods for the Brazils. Jemmet. accompanied by a mariner, named Moore, went to Mr. White, a ship-broker, in London, and entered into negotiation for the purchase of a Portuguese vessel then lying in the Thames. They professed to treat on behalf of the house of Lazarus and Cohen, and purchased the ship for seven hundred pounds, which was paid for at two payments. They then employed Mr. White to procure them freight for Pernambuco. The vessel, which they called the Maria, was then advertised as ready to receive goods, and vast quantities were shipped; among other things, seven casks of dollars, containing thirty-two thousand ounces of silver. The cargo was estimated at eighty or ninety thousand pounds; and the freight, amounting to eight hundred and eighty-six pounds, six shillings, was paid in advance.
In April, 1810, the Maria, Captain da Sylva, sailed from the Downs, where Jemmet went on board; but, instead of proceeding to the Brazils, they shaped their course for the West Indies. On their way from Teneriffe to Porto Rico the vessel's sides were painted yellow, and her name changed from Maria to the Columbia, of New York. The first mate took the command. They were not suffered to break bulk at Porto Rico, and in consequence they proceeded to Porto Plato, in St. Domingo, where they freighted a schooner with part of the cargo, and then sailed to St. Jago, in the Isle of Cuba, where the dollars were landed by Jemmet. They then steered for Havannah, where the crew was discharged, and the vessel dismantled. Neither the owners of the ship nor the cargo ever heard how either was disposed of.
Jemmet, being dishonestly possessed of property, proceeded to Philadelphia, where he procured bills on England for six thousand pounds, with which he returned. But an account of his villainy had preceded him, and on his appearance in London he was taken into custody, and committed to the prison. His trial came on at the Old Bailey, February 28, 1812, when these facts were proved against him by some of his crew, and he was accordingly found Guilty -- Death.