TENNANT, SmurnsoN, a celebrated English chemist, was born at Selby in Yorkshire, on the 30th November 1761, and was the son of the Reverend Calvert Tennant, vicar of Selby. After receiving the elements of his education at Scerton, 'I'adcaster, and Bromley, he went to Edinburgh in 1781 to study medicine, and attend the chemical lectures of Dr. Black. In October 1782 he went to Cambridge, where he devoted himself principally to chemistry and botany. In the summer of 1784 he made a journey to Denmark and Sweden, when he paid a visit to the celebrated Scheele, with whose simple apparatus he was peculiarly pleased. In 1785 he was elected F. R. S., and in 1788 he took his degree of Bachelor of Physic. His mind was then occu pied with chemical pursuits, and in 1791 he com municated to the Royal Society his discovery of a method of obtaining carbon from the carbonic acid. Being fond of travelling, he went to the continent, quitted Paris on the 9th of August, visited Gibbon at Lausanne, and after visiting Rome and Florence, he returned through Germany to Paris, which he found enveloped in all the horrors of the revolu tion. M. Delametherie, to whom he paid a visit, had the integrity to preserve for him some valuable property, which lie found it necessary to put under his charge.
In the year 1796 Mr. Tennant took his degree of M. D., and in the same year he submitted to the Royal Society his paper on the quantity of carbonic acid in the diamond.
About this time he took a passion for farming, and for that purpose he purchased some uninclosed land in Lincolnshire. In 1797 he bought a property on the Mendip hills, near Chidder, where lie built a house, in which he resided during part of every summer. In 1802 he discovered that emery was the powder of corundum, and in 1804 he discovered the two new metals of iridium and osmium, for which he received from the Royal Society the Copley me dal of that year.
In May 1813 Mr. Tennant was elected Professor of Chemistry in the university of Cambridge, and in the spring of the preceding year lie delivered his first and last course of lectures.
In September 1814 Mr. Tennant paid his last vis it to the continent. From Lyons, Nismes, Avignon, Marseilles, and 'Montpellier he returned in Novem ber to Paris, where he remained till February 1815. On the 15th of February he arrived at Calais, and on the 20th he set out with Baron Bulow to embark at Boulogne. They went on board a packet on the 22d, but were driven back by adverse winds, and in tended to make a second attempt in the evening. In order to spend the day they took horses to pay a visit to Bonaparte's pillar, about three miles dis tant, and having on their return gone to look at a small fort, on which the drawbridge over a fosse, 20 feet deep, wanted a bolt, they had no sooner got upon it than it gave way, and both of them, with their horses, were precipitated into the ditch. Ba ron Bulow, though stunned, escaped without any serious injury, but Mr. Tennant was found lying un der his horse apparently lifeless. His skull and one of his arms were dreadfully fractured, and though when brought to the hospital he seemed to recover his senses, yet he died within an hour. His re mains were interred in the public cemetery at Bou logne.
The following is a List of his Principal Papers in the P hilosophical Transactions.
1. On the Dccompositon of fixed Air, 1791, p. 182.
2. On the Nature of the Diamond, 1797, p. 122.
3. On the Action of Nitre upon Gold and Pla tina, id. p. 217.
4. On the different sorts of Lime used in Agri culture, 1799, p. 305.
5. On the Composition of Emery, 1802, p. 398.
6. On two Metals found in the Black Powder re maining after the Solution of Platina, 1804, p. 411.
7. On an easy mode of producing Potassium, 1814, p. 578.
8. On the Means of producing a double Distil lation by the same heat, id. p. 587.
9. In the Geological Transactions, vol. i. 1811, he published an Analysis of a Volcanic Substance containing the Boracic acid.
For a full and minute account of the life of this eminent chemist, and accomplished individual, see Mr. \Vhishaw's Biographical account of him in Dr. Thomson's .Innals of Philosophy, vol. vi. pp. 1 and 80.