When his brother, Alexander, obtained a position for him in Brazil, Paterson co-founded the Tropicalista School of Medicine in Brazil, along with
O. E. H. Wucherer (1820-1873) and
José Francisco da Silva Lima (1826-1910). Paterson lived in Bahia for a quarter of a century. He was elected a fellow of the Botanical Society of Edinburgh on July 11, 1872. Deeply interested in botanical science, he donated about forty tropical plants to the Society's garden, including
Musa coccinea (the "flowering banana"). He was a friend of
Emperor Pedro II of Brazil, who awarded him with the title of Knight of the
Order of the Rose (1859), later adding the honorifics of Official (1870) and Commander (1872) of the same order. Paterson was particularly revered in Bahia because he cared for the poor and enslaved as well as the Bahian elite. He died suddenly in
Salvador, the provincial capital, having returned there from Edinburgh to look after his brother Alexander, who was suffering from paralysis. He was buried in the
British Cemetery of Bahia. ==Personal life==