Among those who had called for a mission to China was Sir Joseph Banks, 1st Baronet, President of the Royal Society. Banks had been the botanist on board HMS "Endeavour" for the first voyage of Captain James Cook, as well as the driving force behind the 1787 expedition of HMS "Bounty" to Tahiti. Banks, who had been growing tea plants privately since 1780, had ambitions to gather valuable plants from all over the world to be studied at the Royal Botanic Gardens at Kew and the newly established Calcutta Botanical Garden in Bengal. Above all, he wanted to grow tea in Bengal or Assam, and address the "immense debt of silver" caused by the tea trade. At this time, botanists were not yet aware that a variety of the tea plant ("camellia sinensis" var. "assamica") was already growing natively in Assam, a fact that Robert Bruce was to discover in 1823. Banks advised the embassy to gather as many plants as possible in their travels, especially tea plants. He also insisted that gardeners and artists be present on the expedition to make observations and illustrations of local flora. Accordingly, David Stronach and John Haxton served as the embassy's botanical gardeners. Dundas laid out his goals for the mission in Macartney's official instructions. More British subjects had been trading in China than any other Europeans. Despite this, the British had no direct contact with the emperor, in contrast to the Portuguese, whose Jesuit missionaries retained permanent positions at the imperial court. Macartney was instructed to negotiate a relaxation of the Canton System, such that British traders could operate in more ports and markets, and to obtain a small island on the Chinese coast from which British merchants could operate under British jurisdiction. He was also to establish a permanent embassy in Beijing so as to create a direct line of communication between the two governments, cutting out the Cantonese merchants who had served as middlemen. Finally, he was to gather intelligence on the Chinese government and society, about which little was known in Europe at the time.