[1] Until the age of 16 Templeton attended a progressive, co-educational, school favoured by the town's liberal, largely Presbyterian, merchant class.
Schoolmaster David Manson sought to exclude "drudgery and fear" by combining classroom instruction with play and experiential learning.
[2] Templeton counted among his schoolfellow's brother and sister Henry Joy and Mary Ann McCracken, and maintained a warm friendship with them throughout his life.
The union between the two already prosperous merchant families provided more than ample means enabling Templeton to devote himself passionately to the study of natural history.
Like many of his liberal Presbyterian peers in Belfast, Templeton was sympathetic to the programme and aims of the Society of United Irishmen: Catholic Emancipation and democratic reform of the Irish Parliament.
In March 1797 his friend, Mary Ann McCracken, wrote to her brother:[6] [A] certain Botanical friend of ours whose steady and inflexible mind is invulnerable to any other weapon but reason, and only to be moved by conviction has at last turned his attention from the vegetable kingdom to the human species and after pondering the matter for some months, is at last determined to become what he ought to have been months ago.She hoped his sisters would "soon follow him."
[8] He nonetheless withdrew from the Belfast Literary Society, of which he had been a founding member in 1801, rather than accept the continued presence of Dr. James MacDonnell.
MacDonnell's offence had been to subscribe forty guineas in 1803 for the capture (leading to execution) of the unreformed rebel Thomas Russell who had been their mutual friend.
[9] (While unable to "forget the amiable Russell", time, he conceded, "softened a little my feelings": In 1825, Templeton and MacDonnell met and shook hands).
"Box from Mr. Taylor".Other plants arrived, often as seeds from North America, Australia, India, China and other parts of the British Empire.
John Templeton's interest in botany began with this experimental garden laid out according to a suggestion in Rousseau's 'Nouvelle Heloise' and following Rousseau's 'Letters on the Elements of Botany Here he cultivated many tender exotics out of doors (a list provided by Nelson[11] and began botanical studies which lasted throughout his life and corresponded with the most eminent botanists in England Sir William Hooker, William Turner, James Sowerby and, especially Sir Joseph Banks, who had travelled on Captain James Cook's voyages, and in charge of Kew Gardens.
Banks tried (unsuccessfully) to tempt him to New Holland (Australia) as a botanist on the Flinders's Expedition with the offer of a large tract of land and a substantial salary.
He also assembled text and executed many beautiful watercolour drawings for a Flora Hibernica, sadly never finished, and kept a detailed journal during the years 1806–1825 (both now in the Ulster Museum, Belfast).
[14] Early additions to the flora of Ireland include Sisymbrium Ligusticum seoticum (1793), Adoxa moschatellina (1820), Orobanche rubra and many other plants.
I believe that thirty years ago his acquirements in the Natural History of organised beings rivalled that of any individual in Europe : these were by no means limited to diagnostic marks, but extended to all the laws and modifications of the living force.
The other six volumes are quarto size, and contain 1,090 folios, with descriptions of many of the plants, and careful drawings in pen and pencil and colours of many species.
About ten years ago I [Lett]spent a week in examining these volumes, and as their contents have hitherto never been fully described, I would like to give an epitome of my investigation of them.
All these drawings were executed by Templeton himself, they are every one most accurately and beautifully drawn; and the colouring is true to nature and artistically finished; those of the mosses and hepatics being particularly good.
is in the "* Flora of Ulster," by Dickie, published in 1864, where there is this indefinite allusion—‘* To the friends of the late Mr. Templeton I am indebted for permission to take notes of species recorded in his manuscript."
[17] Antrim:Northern beech fern Glenaan River, Cushendall 1809: intermediate wintergreen Sixmilewater 1794: heath pearlwort :Muck Island Islandmagee 1804: dwarf willow Slievenanee Mountain 1809: thin-leaf brookweed beside River Lagan in its tidal reaches – gone now 1797: Dovedale moss Cave Hill 1797: Arctic root Slemish Mountain pre 1825: Cornish moneywort formerly cultivated at Cranmore, Malone Road, Belfast1 pre-1825 J. persisted to 1947: rock whitebeam basalt cliffs of the Little Deerpark, Glenarm 15 July 1808: yellow meadow rue Portmore Lough 1800: Moschatel Mountcollyer Deerpark 2 May 1820 , Bearberry Fair Head pre 1825, Sea Bindweed Bushfoot dunes pre 1825, Flixweed, 'Among the ruins of Carrickfergus I found Sisymbrium Sophia in plenty' 2 Sept. 1812 – Journal of J. Templeton J4187, Needle Spike-rush Broadwater pre 1825, Dwarf Spurge Lambeg gravel pit 1804, Large-flowered Hemp-nettle, Glenarm pre 1825 Down: Field Gentian Slieve Donard 1796: Lesser Twayblade Newtonards Park pre 1825: Rough poppy 15 July 1797: Six-stamened Waterwort Castlewellan Lake 1808: Great Sundew going to the mountains from Kilkeel 19 August 1808: Hairy Rock-cress Dundrum Castle 1797: Intermediate Wintergree Moneygreer Bog 1797 Cowslip Holywood Warren pre 1825 long gone since: Water-violet Crossgar 7th July 1810 Scots Lovage Bangor Bay 1809, Mountain Everlasting Newtownards 1793, Frogbit boghole near Portaferry, Parsley fern, Slieve Binnian, Mourne Mountains 19 August 1808, Bog-rosemary Wolf Island Bog 1794, Marsh Pea Lough Neagh Fermanagh: Marsh Helleborine John Templeton had wide-ranging scientific interests including chemistry as it applied to agriculture and horticulture, meteorology and phenology following Robert Marsham.
John Templeton studied birds extensively, collected shells, marine organisms (especially "Zoophytes") and insects, notably garden pest species.
This was not published, even in part, but A catalogue of the species annulose animals and of rayed ones found in Ireland as selected from the papers of the late J Templeton Esq.
[22] The library at Leinster House held 12,000 books and was particularly rich in works on botany; "amongst which is a very valuable work in four large folio volumes, "Gramitia Austriaca" [Austriacorum Icones et descriptions graminum]; by Nicholas Thomas Host".Templeton was also associated with the Farming Society funded in 1800, the Kirwanian Society founded 1812, Marsh's Library, Trinity College Botanic Garden.
Never of strong constitution, he was not expected to survive,[23] he was in failing health from 1815 and died in 1825 aged only 60, "leaving a sorrowing wife, youthful family and many friends and townsmen who greatly mourned his death".
With the staff and scholars of the Institution's early Collegiate Department, he then helped form the Belfast Natural History and Philosophical Society (the origin of both the Botanical Gardens and what is now the Ulster Museum).
His library included Rees's Cyclopædia and works by Carl Linnaeus, Edward Donovan and William Swainson s:Zoological Illustrationsand he used a John Dollond microscope and lenses.