Complex sentence: He was employed in the Royal Botanic Garden Edinburgh, and later in the Horticultural Society of London's garden at Chiswick, and following the Treaty of Nanjing in 1842 was sent out by the Society to collect plants in China.
Split into simpler sentences: He was employed in the Royal Botanic Garden Edinburgh, and later in the Horticultural Society of London's garden at Chiswick. Following the Treaty of Nanjing in 1842 Fortune was sent out by the Horticultural Society to collect plants in China.