On 8 June 1834, he sailed from Liverpool to New York. He travelled widely in North America, analysing soil, examining minerals (tradition claims he discovered copper in Canada), and visiting farms to study soil conservation and to analyse the gluten content of wheat. In South America in 1836 he visited the most important mineral areas and he went up the west coast from Chile to California. During this time he became a strong opponent of the slave trade. He went to Cuba, Tahiti and the South Sea Islands, and came to New Zealand probably about the beginning of 1839.