[1][5][6] On account of fraud he emigrated to Brazil, and with Don Pedro I's army arrived in Rio de Janeiro.
Later he lived as a merchant in the province of Cachoeira do Campo, in the State of Minas Gerais, becoming the owner of a farm in the northerly neighborhood of Curvelo, some days' journey north of Lagoa Santa.
On his great journey through the Brazilian countryside in 1833–35, he chanced to meet the Danish naturalist Peter Wilhelm Lund accompanied by the German botanist Ludwig Riedel in October 1834.
For commercial reasons Clausen's acquaintance with Lund turned him into a natural history collector, both of plants and fossil animals.
[3] After returning to Europe he began to suffer from mental problems and so was taken to a hospital in Dartford, London, where he died in 1855.