Smithson Tennant (1761 1815) – Chemist, Agronomist and Liberal Thinker
by David Lewis
Tennants Yorkshire RootsSmithson Tennant was born in Finkle Street, Selby on November 30th 1761. His birthplace still exists, having become licensed premises by 1800. Selby Civic Society and Town Council erected a blue plaque outlining Tennants achievements on the building in 2005.
Tennant was the only child of the Rev. Calvert Tennant and Mary Daunt, both families with deep Yorkshire roots. The Tennant family had long been landowners in the Wensleydale area, and are apparently distantly related to the local land agents of the same name. Calverts family lived at either Mount Park Farm or Park House, both still extant in or near to Wensley itself. Being the second son of the family, Calvert was encouraged to go into the church and gained a doctorate of divinity from St Johns College in Cambridge in 1736.Calvert had ecclesiastical posts in Lund near Hawes, at Castleford and at Great Warley near Romford. He came to Selby in the 1750s, and may well have assisted Marmaduke Teasdale, Selbys vicar, at Selby Abbey and nearby St. Wilfrids, Brayton. Mary Daunts father, William Daunt, was an apothecary, who came to Selby in the early 1750s, but died in the later part of the decade, leaving most of his possessions to wife Rebecca and, on her death, to their only surviving child, Mary.
Calvert and Mary married in Selby Abbey on Midsummers Day, 1759, and their only child, Smithson whose unusual first name stems from his maternal grandparents family was born two years later.
Calvert taught his son Greek and Latin, and he also absorbed knowledge from the Daunt medical texts. It is said that Smithson made gunpowder for his own amusement when he was just 9.Sadly, Calvert died in his sons 10th year. Having shown an interest in Natural Philosophy by attending lectures at Tadcaster when he was 11, Tennant was sent away to school at Tadcaster and then Scorton, near Richmond, but was happy at neither place. He did settle at Beverley Grammar School, at the time closely linked to Beverley Minster. The schools new science labs have a plaque in his honour.
In 1780, whilst considering continuing his education under Dr Joseph Black at Edinburgh, further family tragedy struck, as his mother was killed, on falling from a horse when out riding with her son.
Smithson had inherited wealth and property in Selby and Wensleydale from both the Tennant and Daunt estates. He left Yorkshire behind, as he disposed of his assets over the next 5 five years giving him the resources to live the rest of his life as he wished – and what a life that was!
Moving to Cambridge, he rapidly began to move in scientific circles. Despite being yet to publish a paper, he was elected FRS at the astonishingly early age of 23. Initially studying medicine, he gained his MD in 1796, but decided not to practice as it was said he could not abide the sight of pain and suffering.
In his chemical research, Tennants analytical powers were renowned, and he concurred with Lavoisier, in debunking the phlogiston theory. He also worked to confirm Lavoisiers conjectures of the structure of carbon dioxide and gave strength to the theory of allotropy by showing that graphite and diamond were both chemically equivalent forms of the element carbon.
He took an interest in agriculture, experimenting on seed germination, and ways to remove acidity from soil. He showed that whilst limestone (Calcium carbonate) was beneficial, the Magnesium salt, dolomite, was positively injurious. To carry out this research, he became a landowner in Epworth and in Cheddar, Somerset.
Interest in soil led to an interest in geology, and he was part of a London Society that developed into the Royal Geological Society the first such in the world. His studies also included the nature of meteorites.
Working with his colleague William Wollaston, who he had met in his medical days, in 1804 he isolated two new elements, iridium and osmium, from platina, the ore of platinum. For this work, Tennant was awarded the Royal Societys Copley Medal, its highest honour, which is still granted today.Tennant also had strong social and political views, and was a member of the King of Clubs, a dining club whose members supported Bonapartes ideas. At occasions when the continent was free from war, Tennant toured Europe, appreciating culture and scenery as well as meeting scientific notables such as Berzelius and Scheele. By chance he had passed through Paris on the day before the Terror began.
On his return to Cambridge in 1813, he was elected to the 1702 Chair of Chemistry at Cambridge University. Renowned as a clear thinker and experimental scientist, his first series of lectures in 1814 on the history of Chemistry received hugely favourable reviews.
With Wollaston he investigated the causes of gas explosions in London. This work was a base for Humphry Davys better known application of the principle in the miners lamp.
Tennant returned to France for the winter of 1814. In February 1815, whilst his crossing from Boulogne was delayed, he rode to inspect the foundations of Bonapartes column: earlier in construction than Nelsons, and with Boney defiantly facing away from the nation of shopkeepers. Unfortunately, the bridge over the moat leading to the site had not been secured. It fell under Tennants weight; he was crushed by his steed, and died within the hour. He is buried in the public cemetery in Boulogne.
No authenticated portraits of Tennant survive. Contemporary accounts are fulsome in their praise of the pleasure of his company, his charm and wit, his incisive logic, the clarity of his explanations and his analytical skill. They look kindly upon the untidiness of his personal life, his unwillingness to publish his work formally and his occasional inability to suffer fools gladly. Smithson Tennant was a scientific genius of whom Selby and Yorkshire should be proud.
To find out more:
Archer, M.D. and Haley, C.D. (eds). 2007. The 1702 Chair of Chemistry at Cambridge University of Cambridge. Tennants life is covered in chapter 5, written by Melvyn Usselman.
Several articles in Platinum Metals Review by W. Griffith and D. Lewis
An article in Nature vol. 192 pp 1224 1226 (1961) by A.E Wales marking Tennants bicentenary
Lewis, D. 2011. Smithson Tennant: Selbys Scientific Genius. Fulprint, York. ISBN 978 0 948330 07 0 (available for £4 inc p+p from the author at 32 Church End, Cawood, Selby YO8 3SN)
Hunt, L.B. and McDonald, D. 1982 A History of Platinum and its Allied Metals. Johnson Matthey ISBN 0 905118 83 9 (Tennant and Wollastons work on isolating iridium, osmium, rhodium and palladium are covered in chapter 9)
www.youtube.com/watch?v=fe6SjQRzxZQ A 6-minute video by Professor Martyn Poliakoff concerning Tennants discovery of iridium and osmium
 Photograph by Author;  Photograph by Liz Kirby ©;  Courtesy Beverly Grammar School;  From Philosophical Transactions of the Royal Society;  image from Wikipedia – reportedly in Public Domain
Main image: Osmium crystals from Wikimedia Commons by “Alchemist-hp” under CC BY-NC-ND 3.0 licence / photograph by author / Iridium metal from Wikimedia Commons under CC BY 1.0 licence
[Article © David Lewis 2012]