A brilliant mind can often be entwined with shrewd business sense, says Lisa Jardine in her Point of View column.
The National Portrait Gallery recently launched an appeal to save from export a unique 18th Century portrait - painted in London around 1730 - of Ayuba Suleiman Diallo, a Muslim from a prominent family in Senegal transported into slavery in North America.
Diallo was rescued by an English lawyer, brought to London and became a celebrity at the court of George II.
I was surprised to learn that the man who arranged Diallo's introduction to the king was the founder of the British Museum, Sir Hans Sloane. Sloane was the pioneering medical man who promoted the therapeutic use of quinine.
As a naturalist, he made important contributions to botanical classification. Most famously, as an enthusiast for natural specimens and curiosities of all kinds, his extensive collections became the foundation for the British Museum on his death in 1752.
Sloane's magnificent seven-volume herbarium survives today in the Natural History Museum, while his two-volume Natural History of Jamaica had a reputation comparable to that of Charles Darwin's Origin of Species when it was published in the first decades of the 18th Century.
Sloane succeeded Sir Isaac Newton as president of the Royal Society, a post he held for a great many years.
The association of Diallo with Sloane is a reminder of the way in which early British science, especially botanical classification or taxonomy, was inextricably entwined with the fortunes of the early British colonies, particularly North America and the West Indies.
Out of the profusion of specimens brought back by enthusiasts from around the globe came the urge to organise them so as to prove that they could all be arranged systematically to display God's orderly bounty.
I used to think of Sloane as an urbane, benevolent figure, presiding over the Royal Society in the early 18th Century, and prescribing exotic therapies of Jamaican origin like drinking chocolate and quinine for his wealthy patients.
Recently, however, I have come to recognise that the adventures with which his glittering career began were not quite so respectable. Sloane's fortunes rose with those of a contemporary who was without question a scoundrel.
Sir Hans's first job was as personal physician to Christopher Monck, 2nd Duke of Albemarle. The Duke was the only son of General George Monck, the military commander who had masterminded Charles II's return to the English throne in 1660.
Like so many children of famous parents, Albemarle junior had found it hard to cope with living in his celebrity father's shadow. He grew up to be a dissolute, violent, brawling young man, much given to gambling.
And then in 1686 Albemarle struck it lucky. He was approached by a naval adventurer from Boston, Captain William Phips, who claimed to have located the wreck of a Spanish treasure ship, the Concepción, which had sunk off the coast of Hispaniola (modern-day Haiti) in the 1640s.
Phips was proposing to sail there with a team of divers, equipped with a new-fangled diving bell, to salvage the ship's cargo. Albemarle judged the speculative venture worth a gamble and set up a joint stock company to back it, using his considerable influence with the king, James II, to get royal sponsorship.
For once, Albemarle's rash bet paid off. Phips located and raised a king's ransom in gold and silver, coral-encrusted from the sea floor. The men who had been persuaded to share his investment risk became rich beyond their wildest dreams. Albemarle himself reputedly made £50,000 (that's more than £4m in today's money) on his initial investment of a little over £2,000.
Here was wealth generation on the scale of modern-day currency speculation. London was abuzz with the news of the treasure trove and the individual fortunes made.
Bad weather had prevented Phips from completing the salvage of the Concepción. Surely there was more treasure lying buried beneath polyps in those deep tropical waters?
James II agreed to sponsor a second voyage, this time providing the frigate Assistance and a force of 200 men to protect the divers and their booty. To secure his own share of the profits, James nominated Albemarle - who had this time elected to join the adventurers himself - Governor of Jamaica. As the king's official representative, Albemarle would collect 15% of all monies made for the crown.
In spring 1687, while the Albemarle investment company was deep in negotiations to secure backing for the second Hispaniola voyage, 27-year-old Hans Sloane wrote breathlessly to an out-of-town friend, describing the riches brought back from the first voyage:
"Besides 15 tuns of pieces of eight, they have a great many ingots of Mexican silver in bars, and some quantity of gold, although but little for the divers could not come up with it, it was so weighty.
"The ship being forced of the place with bad weather, came away without bringing all; I believe she'll set sail with us for the same place, from whence you shall hear from me."
As this letter tells us, Sloane had just been invited by Albemarle to join the second treasure-seeking voyage as his personal physician - and had jumped at the opportunity. Not only was he promised a personal fortune, but, as a keen naturalist, the trip would afford him the opportunity to explore the flora and fauna of Jamaica.
Sloane was on board the Assistance when she reached Phips's sunken wreck in December 1687. They found that any accessible treasure that remained had been raised and stolen in their absence by small privateering ships and local adventurers. The trip was a financial failure.
Albemarle retreated to the Governor's Residence at Port Royal to drown his sorrows, his health deteriorating rapidly in the inhospitable climate. Fortunately Sloane had other distractions.
When not prescribing purges and pills to his sickly employer and his friends, Sloane crisscrossed the island on horseback or on foot, collecting plant and shrub specimens, guided by slaves from the sugar plantations with knowledge of local medically useful seeds and grasses.
Ten months after their arrival Albemarle died of what Sloane diagnosed as dropsy and the whole party returned to London, where they arrived just as William III and Mary were crowned joint English monarchs in spring 1689.
I used to believe that it was Lady Albemarle's recommendation of the young family physician on the basis of his ministrations to her dying husband that launched Sloane's career as a medical practitioner after the Jamaica adventure.
When I talked about Sloane's achievements I used to characterise them as exclusively those of a talented physician and naturalist. I imagined Sloane as a wide-eyed young botanist, marvelling at his encounter with the exotic Jamaican habitat, and systematically reducing its lush profusion to the orderly bounds of the doctor's pharmacopoeia.
I now know that Jamaica financed Sloane's successes in rather more prosaic terms. While there, he befriended a wealthy plantation owner and medical man, and subsequently married his widow. On his return to London, Sloane benefited from the substantial profits yielded by her departed husband's Jamaican sugar plantations and buoyant import-export business.
Albemarle's physician may not have had as much success with his Spanish gold-seeking as his noble employer but the Atlantic slave trade, and the bartering and dealing in sugar and sugar-related products including the large-scale importing of cinchona bark - the source for quinine - and cacao, brought him comparable riches. Ballasted by colonial wealth, his medical and collecting careers prospered.
So, Sloane's rise to public prominence as a distinguished collector and scientist came in no small part from his shrewd seizing of opportunities to improve his career prospects, and his eye for suitable openings in the market. He was by temperament an applied rather than a pure scientist, alert to real-life problems and practical opportunities.
For me, this "new" Sloane - the hands-on, shrewdly entrepreneurial Sloane - sits more comfortably with 21st Century images of scientific success in public life than the one I used to have.
Sloane the keen botanist, sitting late into the night in Port Royal, overseeing the painstaking preservation and pasting into folio volumes of his plant-specimens, belongs with a correspondingly old-fashioned view of the early Royal Society, debating genteelly and performing drawing-room experiments, away from the hurly-burly of ordinary, everyday life.
Sloane the colonial entrepreneur is much more a man of his time. He reminds us that in every generation, the brilliant mind - in whatever field - does not float high above everyday life, but is tethered to, and integrated with, the economic and commercial world of his age.