AN AGED BRICK WALL, clearly once the boundary of the grounds of a grand house, runs along part of The Ridgeway in London’s Mill Hill. It bears a plaque commemorating the fact that this was once the site of Ridgeway House, the home of Peter Collinson (1694-1768), author, naturalist, and botanist. This was not a name with which I was familiar, yet he played an important part in the scientific life of 18^th century London and further afield.

Peter Collinson, born a Quaker, the son of the owner of a textile business, was unable to attend university in Britain because in his time members of that branch of Christianity were not admitted. He inherited his father’s business and taught himself to such an extent and to such a high level that in 1728 he became a member of the prestigious Royal Society (www.londongardenstrust.org/features/millhill.htm provides a good biography of Collinson). His greatest interest was plants and gardening, and he was responsible for importing many plants such as magnolias, kalmias, rhododendrons, azaleas and cedars of Lebanon, which were then relatively new to the UK, into the country. He imported these plants in great quantities so that these could be planted all over the country and thereby enriched and transformed the landscape. His legacy may be seen in many of the landscaped gardens of the country’s great houses.

When Collinson’s father-in-law died in 1748, he inherited Ridgeway House in Mill Hill, which was built in about 1525, and moved there from Peckham. Apparently:

“The house had no particular architectural merit; it was described as “double-fronted” with French windows” that open onto the garden.”

Not only did he move his family from Peckham but also all the plants he had been growing there. At Mill Hill he created a wonderful garden, about which he wrote:

“Very few gardens if any excel mine at Mill Hill for the rare exotics which are my delight.”

(Both quotes from www.mhps.org.uk/collinson/botanical-contribution.asp#millhill).

Collinson became a good friend to a frequent visitor to England, the American Benjamin Franklin (1705/6-1790), who became a vegetarian in his teens, but is better-known for other achievements. Many of these were in the field of scientific research. The two men corresponded regularly (https://founders.archives.gov/search/Correspondent%3A%22Collinson%2C%20Peter%22%20Correspondent%3A%22Franklin%2C%20Benjamin%22). Much of the contents of their letters that sailed across the Atlantic concerned the exciting discoveries that Franklin was making in fields such as electricity. In the letter dated 28^th of March 1747, Franklin thanked Collinson for his:

“… kind present of an electric tube, with directions for using it, has put several of us on making electrical experiments, in which we have observed some particular phaenomena that we look upon to be new. I shall, therefore communicate them to you in my next, though possibly they may not be new to you, as among the numbers daily employed in those experiments on your side the water, ’tis probable some one or other has hit on the same observations.”

Other matters were also discussed. For example, in a letter dated 9^th of May 1753, Franklin wrote to Collinson:

“I have often observed with wonder, that Temper of the poor English Manufacturers and day Labourers which you mention,  and acknowledge it to be pretty general. When any of them happen to come here, where Labour is much better paid than in England, their Industry seems to diminish in equal proportion. But it is not so with the German Labourers; They retain the habitual Industry and Frugality they bring with them, and now receiving higher Wages an accumulation arises that makes them all rich.”

Much of Collinson’s correspondence with Franklin was to keep the latter up to date with scientific developments in Europe, especially those relating to new German experimentation with electricity. And much of Franklin’s correspondence with Collinson reported the results of his experiments with electricity in America, which Collinson conveyed to The Royal Society. It was these letters that were the basis of a book published by the Royal society in 1751, “Experiments and Observations on Electricity”, which is one of the most important scientific publications to emerge from 18^th century America.

I cannot discover for sure whether Franklin ever visited Collinson in Mill Hill. However, Collinson did host the Swedish naturalist Daniel Solander (1733-1782), assistant to the great Swedish botanist Carl Linnaeus (1707-1778), at Ridgeway House. Linnaeus had earlier visited Collinson in Peckham. The Victorian guidebook writer James Thorne suggests that Linnaeus himself  also visited Collinson at Ridgeway House.

Solander travelled to England in 1760 to promote the system of classification of biological organisms devised by Linnaeus. In 1753, Linnaeus named a genus of flowering plants, ‘Collinsonia’, to honour Collinson. It was Collinson, who got Solander the job of classifying the natural history specimens in Sir Hans Sloane’s collection, which formed the basis of the recently established (1753) British Museum, which opened to the public in 1759. It was the combined efforts of Collinson and Solander that persuaded the British to accept the Linnean system of classification. In 1768, Solander was one of the participants on Captain Cook’s first voyage to the Pacific Ocean, and thus became the first Swede to circumnavigate the Earth.

Collinson died in 1768. From 1801, his property at mill Hill was owned by the botanist Richard Anthony Salisbury (1761-1829), a founder member and the founder Secretary of the Royal Horticultural Society. In 1807, he sold it to the group who founded the Protestant Dissenters Grammar School. the forerunner of Mill Hill School. Apart from six trees in the school’s grounds, much of Collinson’s collection of plants has disappeared. Ridgeway House, which housed the school at first, was demolished in 1826 when the present grand school buildings were constructed. Collinson would have been pleased to know that Mill Hill School was:

“… first educational establishment to provide a first class education for the sons of dissenters, those whose religious or philosophical outlook did not conform to that of the state and who, like Collinson, a Quaker, were barred from the attending the established seats of learning.” (www.mhps.org.uk/collinson/botanical-contribution.asp#millhill).

When I saw the old wall running beside the Ridgeway in Mill Hill and what was written on the plaque affixed to it, little did I realise that such an important man in the scientific community of the 18^th century had lived on the other side of it.