smithson tennant, f.r.s. (1761-1815)

Smithson Tennant, F.R.S. (1761-1815)Author(s): Donald McDonaldSource: Notes and Records of the Royal Society of London, Vol. 17, No. 1 (May, 1962), pp. 77-94Published by: The Royal SocietyStable URL: http://www.jstor.org/stable/531015 .

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77

SMITHSON TENNANT, F.R.S. (I76I-I815)

By DONALD MCDONALD

T HE discovery of two of the chemical elements (osmium and iridium) 1 and close association with that of two others (rhodium and palladium)

has not fallen to the lot of many people and of them, until quite recently, Smithson Tennant must have been one of the least known. Nevertheless, he had many admirable qualities and in his lifetime held an influential position among a great number of friends, a fact to which we owe the preservation of such details of his life as have survived. On his death it was they who thought that some memory of him should be kept alive, and one of them, John Whishaw (assisted by another, Henry Warburton) took upon himself the task of collecting and editing the recollections of them all. Whishaw was a near contemporary of Tennant at Cambridge and remained his life-long friend. He qualified as a lawyer and spent thirty years as a Commissioner in the Audit Office, during which time he became a most notable man-about-town, knowing all the prominent people in the worlds of politics, art, science and literature. At Holland House, one of the principal resorts of such people, he earned the title of 'The Pope' (I). The result of his work on Tennant was published in Thomson's Annals of Philosophy in I816 (2) and subsequently, with some tidying-up and the addition of four paragraphs, the article was issued separately as a 46-page pamphlet (3) for distribution among the friends. Both these publications were anonymous, but Dr A. E. Wales (4) reports a complete identification of Whishaw as the author in a letter from the latter to David Ricardo, dated 8 August 1815:

'With the assistance of Mr Warburton, I have written a short Memoir of the Life of poor Mr Tennant for insertion in Dr Thomson's Scientific Journal. A few copies will be printed off for distribution among his friends.' (5)

Later writers about Tennant have relied heavily on Whishaw's work, includ- ing the important contributions of Thomson in his History of Chemistry (6) and Dr Harden in The Dictionary of National Biography (7). Since then Mary Elvira Weeks (8) has brought in references to Tennant in the correspondence of Berzelius, who met him and stayed with him both in London and in the country in I812. But the major modern contribution to the story has been that of Dr Wales, starting with his thesis of 1940 (4) and continuing up to his outstanding bicentenary article in Nature in December last (9). He has



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filled in some gaps in the Whishaw story, and corrected some mistakes in it. His work has been invaluable in helping us in the study of a most interesting character.

Smithson Tennant was born on 30 November 1761 in or near Selby, Yorkshire, and was baptized in the Abbey there four days later (9). He was the only child of the Rev. Calvert Tennant and his wife, nee Mary Daunt. The father has been described by Whishaw and his followers as Vicar of Selby, but at that time there was no vicar in Selby (Io), and there is so far no evidence whatever that Calvert Tennant held any church appointment there, although of course as a visiting clergyman, he may have sometimes assisted in the Abbey services. A full summary of his life exists in the Records of St John's College, Cambridge, of which he was a Fellow (ii). He was the son of Edward Tennant, a farmer ofParkhouse, Wensleydale, and was baptized there on 2 September 1716. He was educated at Sedbergh School and entered St John's in 1736, graduating B.A. in I739. He was ordained deacon in 1740 and became curate at Lund near Hawes. This only lasted a year, when he moved to Castleford and was ordained priest. On 24 March 1742/3 he was admitted a Lupton Fellow of St John's and he must have gone into residence in Cambridge again, since he was a junior proctor in I749-50. In 1751 he took the degree of B.D. In 1758 he was presented by his College to the rectory of Great Warley in Essex, which he retained till his death in 1772. The marriage of the 'Rev. Calvert Tennant of Great Warley and Mary Daunt of Selby' took place at Selby Abbey on 21 June 1759 (I2). His wife came from an old Selby family and was the daughter of William Daunt, variously described as doctor, surgeon and apothecary, and probably something of each, as was quite usual in small provincial towns in those days. According to Dr Wales (4) he had considerable property in land in the Selby area and also a good library of books related to his profession. Mrs Tennant returned to her parents' home for the birth of her son and it is highly doubtful whether she ever returned to Great Warley. The Registers there show that Tennant signed banns and witnessed marriages there in 1758 and 1759, but after September in the latter year his name does not appear at all. It seems evident therefore that he became an absentee rector, living at his wife's home at Selby, leaving Great Warley to a curate.

From his earliest days, the education of the young Smithson Tennant was taken in hand by his father, who began to teach him Greek at the age of five, but unfortunately he died in 1772 when the boy was ten. After that his education seems to have lacked direction and he drifted to different Yorkshire Grammar Schools at Scorton (Swaledale), Tadcaster (Wharfedale), and



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Beverley (near Hull), without deriving much solid satisfaction or benefit from them or from the life that he found there. But very early there began to emerge in him an interest in natural science, particularly chemistry. He began to read about these subjects and to make small experiments. He himself used to relate how, at the age of nine, he prepared the gunpowder for his own fireworks, and while he was at Tadcaster he attracted attention by the nature of his questions to a visiting lecturer on science. At Beverley he found a well- equipped library and gave much time to this, mentioning particularly Newton's Treatise on Optics. Dr Wales records (4) that 'there is a story of Tennant about this time exercising his enquiring mind by collecting the moonbeams in a large concave mirror to see if there were any sensible heat and buttering the mirror to see if it would melt it'.

On leaving school he was eager to put himself under Dr Priestley, but unfortunately the latter's arrangements did not permit this, and just about this time (1781) his mother died, being thrown from her horse while riding beside him, and killed on the spot.

So he arrived at the threshold of manhood, treated unkindly by fate in losing both his parents, lonely as an only child must have been in such circumstances, with an experience of schools that left no moulding memories, but yet with two positive endowments that could shape the course of his life. One was the bent towards science and experiment, and the other was a competent knowledge of Greek and Latin and of their literatures, so that he had a foundation on the one hand for imagination and enquiry, and on the other for perception and taste. In choosing a profession, he turned to medicine, as being closely related to his inclinations and to his memories of his grand- father, so accordingly in 1781 he went to Edinburgh, where by a stroke of good fortune he came under Dr Joseph Black, a man who was at the heart of the revolution that was taking place in chemical ideas. Tennant always had the highest respect for him, and he in turn appreciated his pupil, as Whishaw's little story (3) shows: 'Mr Tennant being at breakfast with him one morning, the conversation turned upon the new doctrine concerning heat; and some experiment was made, in which the temperature of a liquid was to be tried by the thermometer. Mr Tennant, immersing the instrument in the liquid, instead of waiting during a long interval, until the mercury became stationary, noted the point to which it immediately rose; and then heating it above the temperature of the liquid, noted the point to which it fell: upon which Dr Black observed, "I see, young man, that you know how to make an experiment!"'

He had enrolled for classes in surgery, chemistry and materia medica (13)



8o

and studied assiduously. In the Department of Mineralogy and Petrology at Cambridge there are preserved nine books in his handwriting of the notes that he took on the lectures (I4). Dr Wales (9) suggests that Tennant obtained from Black his first introduction to platinum. Certainly the printed version of the latter's lectures ( 5) shows a very complete knowledge of all that was known about the metal at that time, but the letter that he received from Sir John Macpherson (I6) purporting to describe how it was being handled on a commercial scale in Spain is not likely to have told him anything new.

In 1782 Tennant came of age and entered into his inheritance. The land at Selby that Dr Wales mentions (4) no doubt came to him and possibly there was Wensleydale land from his father; probably these were the basis of the undoubtedly large private means which he enjoyed throughout his life. In October 1782, he moved from Edinburgh to Cambridge and entered Christ's College as Pensioner to study chemistry and botany. Shortly afterwards he became a Fellow Commoner; Whishaw suggests that this was to avoid some of the restrictions of ordinary undergraduate life. He matriculated in December 1784 but transferred to Emmanuel in December 1786. His four years at Christ's were very formative ones, providing as they did the founda- tions of his mastery of chemistry and of some of his lasting friendships. As regards the former, he now began definitely to concentrate his attention on this subject and Dr Harden (7) is no doubt right when he says that it was during his time at Christ's that, following his old master Black, he satisfied himself that the theory of phlogiston was no longer acceptable, a good many years before this proposition obtained general support. As for his friendships, this was undoubtedly a happy period for him. Whishaw says: 'His health was then vigorous, his spirits were constant and unwearied, and his talents for society perhaps yet more striking and brilliant than in his after years. He was distinguished ... by an extent of information, and maturity of judgement, which might have seemed to be the results of a long life of study and reflection; and these extraordinary attainments derived an additional interest, and peculiar grace, from the simplicity of his manners, the playfulness of his wit, and the careless, fascinating beauties of his conversation.' All those long words might easily be taken as presenting a most superior person, but there is another little story rather more eloquent about the later stages of a College Dinner which tells how he won a bet that a shilling weighed more than a half- sovereign (I7).

In the summer of 1784 he made his first journey abroad, to Denmark and Sweden, for the purpose of meeting Scheele. Such an expedition was not



8i

undertaken lightly, because he was a victim of serious sea-sickness, which, under the condition of travel in those days, was no light burden. Scheele made a considerable impression on him and showed him some interesting experiments. It was also probably on this occasion that he met Gahn and from him derived a rising interest in mineralogy and the use of the blowpipe in the analytical work connected with it.

On I3 January 1785, while still an undergraduate, and at the age of 23, he was elected a Fellow of the Royal Society with a strong representation of distinguished Cambridge Fellows among his supporters.

Among his intimate friends at Christ's was Sir Busick Harwood, who had been a surgeon in India but had met with misfortune there and had to start life afresh. This was the reason for his presence in Cambridge as an undergraduate seeking a medical degree. In spite of the disparity in their ages, Tennant and he formed a cordial friendship in which the broad experience of the older man had a great formative influence on the receptive mind of the younger. In December 1786 Harwood decided to leave Christ's for Emmanuel and Tennant moved with him. While at Emmanuel he paid a visit to Paris, where he met several of the principal French chemists, but unfortunately he fell so ill that Harwood had to go out to bring him home. This he did by way of Holland and what is now Belgium. Another incident of this period is reported by Whishaw (3) as showing the 'independent and benevo- lent turn of mind which distinguished his character throughout life. A Russian gentleman had been sent to the University by the Empress Catherine to be instructed in mathematics, with a view to an acadenmical appointment at some place of military or naval education in Russia. The remittances necessary for the payment of his expenses were at first regularly made; but subsequently, in consequence of some accident or omission, were discontinued.' After a time the College authorities became impatient and sought to sue the student, whereupon Tennant 'immediately took steps to procure his release and advanced him the means of support till he was enabled to return to Russia'.

In 1788 Tennant took his degree as Bachelor of Physic and soon after left Cambridge for London. No information is available as to his life during the next three years and as to how far he was engaged in the preliminaries of the medical profession, but it is quite evident that he was following his bent for experimental chemistry, since on 31 March 179I (4) he presented his first paper to the Royal Society. This was 'On the Decomposition of Fixed Air'(I8) in which he described how carbon dioxide, by heating calcium carbonate with phosphorus, could be made to yield carbon, so confirming analytically Lavoisier's earlier discovery by synthetic experiment that the gas was a

6



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compound of carbon and oxygen. Incidentally, in his experiment, Tennant achieved the first production of calcium phosphide.

In the summer of 1792 he again visited Paris, observed the revolutionary tension there and was fortunate to leave the city on 9 August, the very day before the rising of the Commune. He passed through Lausanne, where he met Gibbon, and went on to Italy, where he studied the work of the great artists in Florence and Rome and was especially influenced by the magni- ficent work of Raphael in the galleries of the Vatican. Returning through Germany, he 'was much amused by the mixture of science and credulity which he found in some of the German chemists', who were even prepared to introduce him to a possessor of the philosopher's stone. To Tennant's great amusement, this introduction was effected 'with much pomp'. After that he returned to Paris and was confronted by the Revolution and its Terror. He called upon Delametherie, the editor of the Journal de Physique and 'found the doors and windows closed as if the owner was absent. Being at length admitted, he found his friend sitting in a back room, by candle- light and with shutters closed, in the middle of the day. On his departure, after a hurried and anxious conversation, his friend conjured him not to come again, as the knowledge of his being there might be attended with serious consequences to them both.'

Returning to London early in 1793 (4), he settled in chambers at 4 Garden Court, Temple, and this became his permanent town residence for the rest of his life. At first he assiduously attended the London hospitals and kept up his reading in the progress of medical science, but after taking his Cambridge Doctorate of Physic in 1796, he was confronted with a need to decide whether to take up the profession definitely or not. Whishaw records the result: 'after some hesitation, he wisely relinquished a design, which, whether successful or not, was unlikely to contribute to his happiness. His desires were moderate, and his private fortune exempted him from the necessity of following any employment as the means of subsistence. He was at liberty, therefore, to indulge his own inclinations.' He had discovered, too, in the course of walking the hospitals, that what Whishaw calls his 'keen and exquisite sensibility' could not suffer the continued presence of pain and misery. So he abandoned finally all ideas of entering medical practice.

But his interest in chemistry, pursued in his own time and under no pressure, went on, and in 1796 he sent his second paper to the Royal Society (19) on 'The Nature of the Diamond', where he again confirmed the work of Lavoisier by showing that the powdered diamond, when fused with nitre in a gold tube, produced precisely the same amount of carbon dioxide



83 as did the same weight of charcoal. In the course of this work, Tennant noticed that both gold and platinum were corroded when heated with nitre and this was the subject of his third paper to the Royal Society 'On the action of nitre on gold and platina' (20).

In his later days at Emmanuel, Tennant became interested in, and friendly with, a young fellow-student in chemistry, five years younger than he, William Hyde Wollaston, who was at Caius from 1782 to I789. The latter, a very keen student indeed, was especially interested in Tennant's accounts of the analytical techniques of Scheele and Gahn, and before long was expressing 'his despair of ever becoming Tennant's equal as a chemist' (14). Already there was much in common between the two men, for Wollaston also was qualifying to be a doctor and finding his interest straying to chemistry and botany. Actually, after leaving Cambridge in 1789, he did start in medical practice, but this was another case of a sensitive man upset by the sight of pain and strongly attracted to chemical research; so, like Tennant, he gave it up. But there was one great difference between the two cases. Tennant had private means and was under no pressure to earn his living; Wollaston had no such resources, and had to find remunerative work. In his student days at Cambridge he had become interested in platinum and is said to have tried to weld it on a blacksmith's forge (14). His friendship with Tennant must have begun before the latter's work on the diamond, since Thomson (6) relates a story which he says was told him by Wollaston 'who was present as an assistant', that 'Mr Tennant was in the habit of taking a ride on horseback every day at a certain hour. The tube containing the diamond and saltpetre was actually heating and the experiment considerably advanced when, suddenly recollecting that his hour for riding had come, he left the com- pletion of the process to Dr Wollaston and went out as usual to take his ride.' From this it seems likely that the work on the diamond was carried out while the two men were still at Cambridge, that is before the latter part of 1788, when Tennant left the University, to be followed by Wollaston a few months later. Whishaw says that it was done 'some years' before the publication.

However this may be, there can be no doubt that there began a very close collaboration between the two men on the subject of making platinum available to science and later to commerce, the mainspring being Wollaston's need to find something on which to base his living and to support his research; on Tennant's side there was friendship, a keen scientific interest and the ready availability of enough funds to finance the work. So, from 1799 or 1800 they set up a probably informal partnership for examining the properties and appli-



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cation of this new metal, and especially the means of getting it into malleable form for conversion into articles.

But in the meantime Tennant had been otherwise engaged. After his rejection of the medical profession, he began to interest himself in agriculture. His health had been calling for occasional journeys out of London and to this end, in about 1787, he paid a visit to a friend at Epworth in the Fen country. This was at the time when large areas of land were being brought under the plough for the first time as a result of the Enclosure Acts. His host was engaged in this work and Tennant himself bought a few plots to experiment on the promotion of fertility in this rough land. His interest increasing, a year or two later he bought a considerable tract of newly-enclosed land near Cheddar (Dr Wales (4) says 500 acres at Shipham in the Mendips). There he built a small house, which he used to visit for some months each summer, as well as at odd times in the intervals, so deriving pleasure, exercise, and better health for the rest of his life. His experimental work was chiefly concerned with the application to the new land of lime, and he was soon seeking a reason why lime from some sources had a bad effect on the germination of seeds. This trouble he tracked down to the presence of magnesia in lime from the burning of dolomitic limestone from the Midlands, and reported accordingly in a paper to the Royal Society (21) 'On the different sorts of lime used in agriculture'. After that he continued quantitative experiments on liming the ground and in 1812 he showed his oatfield to Berzelius, with 'tall, well-developed oats at the highly limed end and sickly plants at the other' (8). According to Whishaw, in the early years his work was not profitable, but, as his experience grew, the situation improved and 'was attended with a reasonable degree of success'. This work must have contri- buted notably to the progress of agriculture on newly-enclosed land.

Tennant's next paper to the Royal Society came in 1802 (22) and was 'On the nature of Emery', which he showed to consist chiefly of alumina, like 'the Corundum of China'.

Meanwhile the partnership with Wollaston had gone into action. Late in I8oo they bought nearly 6000 ounces of native platinum and Wollaston proceeded to attack it with aqua regia (I4). The reasons for this were to separate from it the iron and other impurities that vitiated its malleability, and to investigate the possibility of the presence of hitherto unknown elements, all necessary preludes to laying down precise methods for refining and fabrica- tion. There seems to have been an understanding between the two men that Tennant would examine the insoluble part while Wollaston looked into the solution. The former had hitherto been dismissed as merely graphite, but



Tennant had other ideas, and the fact that in the early days of his work he mentioned it to SirJoseph Banks gives it priority over that of the Frenchmen, Descotils and Vauquelin, who were treading closely on his heels. For a long time chemists had been puzzled by the varying tints of orange and red exhibited by the precipitates that they obtained when they added ammonium chloride to solutions of native platinum in aqua regia, and in 1803 Descotils (23) expressed the opinion that this was due to the presence of an unknown metal. About the same time Vauquelin had obtained a volatile oxide by treating the insoluble black powder with alkali and thought that it belonged to the same unknown metal (24). Tennant studied this work carefully and went on to discover that there was not one new metal in the material, but two, the properties of which he elucidated and which he named iridium and osmium. On 21 June 1804 he described the work in detail in a paper to the Royal Society (25). This is a model of clarity and precision, and the French chemists paid tribute to it by accepting at once its priority over their own work. For this and his other researches the Royal Society awarded to him their Copley Medal for 1804. In the meantime Wollaston was pushing on with his part of the work on the soluble portion of native platinum and in the same year he announced his discovery of rhodium and palladium (26).

While all this scientific work was going on, the two partners were also engaged in attempts to make platinum commercially useful. Wollaston's knowledge that four other similar metals were present in the raw material as well as iron enabled him to remove them, at any rate partially, and so he was able to obtain platinum in a reasonably pure state and fully malleable by methods later disclosed by him in 1829 (27). Gilbert (14) states that the first record of crucibles concerns five, with covers, dated 13 February I805, and slightly later we have the well-known reference to Dr. J. Kidd's 'crucible of platina prepared by Dr Wollaston'. (28) But at the same time the partners were tackling larger work in boilers for concentrating sulphuric acid, in which form they eventually sold in all 7000 ounces between I805 and 1820 (14). The first was for one Sandman, a chemist of Southwark, which was the first made in this country and probably in the world. The next was made in 1809 for a larger manufacturer, T. Farmer of Kennington, and after that a succession fully recorded by Gilbert (14). The same authority states that by the time of Tennant's death, the joint profit had been about J700 over an expenditure of about I0oooo.

During this period (1805-6) Tennant twice visited Ireland and on one of the journeys accidentally met Wollaston there and visited the Giant's Causeway with him. On the other journey he was accompanied by his



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friend W. J. Browne, a well-known traveller in the East. Tennant was very interested in the people and civilizations of the Middle and Far East and was fascinated by their histories, their stories, their manners, their religions and their art. He bought books and pictures dealing with them and eagerly cultivated the acquaintance of anyone who had travelled in those parts. Browne came into this category and to him Tennant became sincerely attached. In a letter written just after Browne had come to an untimely end in I813 at the hands of brigands in Persia, Tennant recalled the evenings that he had often spent with him at the Adelphi 'where I used to go whenever I found myself gloomy or solitary; and so agreeable to me were these soothing romantic evening conversations that, after ringing his bell, I used to wait with some anxiety, fearful that he might not be at home' (3).

Tennant was never a man of great physical strength, in fact during the later years of his life he was never fully well. To maintain his circulation he had to take frequent exercise and preferred to take it on horseback. Thomson (6) reports that 'he was always a bad horseman so that these rides were sometimes a little hazardous, and I have more than once heard him say that a fall from his horse would some day prove fatal to him'. We have already mentioned the death of his mother and about I808 he himself broke his collar bone in a similar accident at Brighton. Fate dogged him to the end in this respect.

In his earlier years in London, his life was rather a retired one, confined to his scientific studies, his travels and his reading, but later he began to retrieve from his memories of his college days his interest in people and conversation. In short, he became a man-about-town and was most welcome at the chief centres of the social life in London, especially at Holland House (I). In 1798 he became a member of the exclusive Whig dining-club 'The King of Clubs', and met many prominent people there (I).

Ever since his visit to Scheele and Gahn in Sweden in 1784 he had been interested in the young science of mineralogy and, in the course of his con- tacts with the famous travellers, had formed a collection of mineral specimens. This led in I812 to a series of lectures on the subject to his friends in an audience of which Whishaw remarks somewhat acidly that it, 'though consisting principally of females, included many individuals distinguished in science and literature'. Eventually he gave a series of four lectures 'each of which was of great length; yet the interest of his hearers was never in the least suspended' and the commentator notes the great clearness of his state- ments, the happiness of his illustrations and 'the spirit and variety with which every subject was discussed'. But his party manners were not always upper- most. There was a man named J. L. B. Burchardt, who was going out to



87 West Africa to investigate the minerals there. Whishaw reports that he was sent to Tennant for some instruction and that the latter went to considerable pains to give it to him. But Burchardt, reading this later after Tennant's death, complained that the latter had done nothing more than 'to produce sometimes a few specimens and to ask whether I knew what they were!' (I).

Tennant's interest in mineralogy probably derived support from his membership of the Askesian Society. This was founded in 1796 and met at the famous Plough Court Laboratory of William Allen, the pharmacist, where it was supported by most of the prominent scientists of the day. In due course it amalgamated with the British Mineralogical Society and later the two became the Geological Society. In I8II Tennant read a paper to the latter on 'Native Boracic Acid from the Lipari Islands' (29), and in I813 he gave them a general lecture on the principles of mineralogy, in which he drew attention to the existence among minerals of many definite chemical compounds, some of which could be prepared artificially in the laboratory (30).

In 1813 the Chair of Chemistry at Cambridge became vacant and Tennant was urged by his friends there to apply for the appointment. He did so and was elected Professor in May 1813. In the spring of 1814 he delivered his first and only course of lectures to a large class which is said to have included Charles Babbage and J. F. W. Herschel. Whishaw says that 'the impression made by these lectures will not soon be forgotten in the University' and he goes on to speculate on how great would have been the value if Tennant had been allowed to continue and develop them over the years.

In June I814 came his last two communications to the Royal Society. The first of these was 'On an Easier Mode of Procuring Potassium than that which is Now Adopted' (3I) and the second 'On the Means of Procuring a Double Distillation by the Same Heat' (32). The latter goes back to an experiment of his Cambridge days, in which he boiled water in one vessel and passed the steam through a coil in a second and closed vessel of water over which he maintained a partial vacuum. Under these circumstances the steam from the first vessel boiled the water in the second. There were also some other pieces of work with which Tennant had been occupied before he set out on what was to be his last journey and which were therefore never written down. One of these is described by Whishaw as 'making sugar from starch with oxalic acid instead of sulphuric acid', but this seems to be part of a large field that was explored by Tennant and Wollaston in the course of their commercial work (I4). They took in quantities of argol



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(crude potassium bi-tartrate) and made from it tartaric and oxalic acids and oxalates. Between 1802 and 8I I some 2' tons of these products were made. They also extracted citric acid from lime juice; Gilbert reports the purchase in 1811 by Tennant of 800 gallons of the latter. No mention is made of any use of oxalic acid for making sugar. Another of these odd pieces of work concerned Tennant's discovery of the presence of iodine in seaweed, which he mentioned in a letter to Berzelius. Another one concerned the refractive powers of compound bodies compared with those of their constituents, and yet another on the improvement of optical glass (it is interesting to note that Wollaston published papers on both these subjects). He also had some scribbled notes on the ability of one metal to displace another from its solution. But probably the most important work of Tennant that was never formally published was that on the passage of flame through small tubes.

In the autumn of 1813, when the use of coal-gas for lighting was beginning to spread, there was considerable public anxiety when the newly- chartered Gas Light Company erected a large gas-holder in Westminster, after one of a similar kind in Woolwich had blown up in January 1812. On 29 January 1814 the Home Secretary sent a letter to the President of the Royal Society asking him to appoint a Committee to examine the question (33). Such a body of eight persons was at once convened and it included Mr Tennant and Dr Wollaston. It held two meetings on 7 and I5 February 1814 and reported after the latter that 'experiments made by two members-have ascertained that flame cannot be communicated through a pipe of the size used for supplying the lamps, in coal gas mixed with any proportion from one to five times its bulk of air'. Moreover, they drew attention to the large quantity of air which was necessary to make an explosive mixture with the gas-at least five times its volume. This report removed the public anxiety and the Gas Industry was able to resume its progress.

In contemporary references to this incident it appears always to be assumed that the two members in question were Tennant and Wollaston, but that it was Tennant who did the experimental work, since it is always his name alone which is attached to it. So far no details have been found of this work, but one can draw conclusions from contemporary comments that point to Tennant finding that a coal gas-air flame would not pass along small copper tubes at all, and that in any case a large excess of air was required to make the mixture explosive. This enabled the Committee to report and Tennant did no niore. But undoubtedly there passed into public knowledge the idea that flames will not pass through small metal tubes.



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In the autumn of 1815 there was serious trouble in the Durham coal- fields with disastrous explosions of fire-damp, caused by the naked flame of the miner's lamp. The Rector of one of the parishes wrote to Humphry Davy, with whom he was acquainted, asking for the help of science in solving the problem (34). Davy responded at once and began to work on a closed lamp to which the necessary air for the flame was supplied in a manner that could not transmit explosion. Later, in November, when he described his work to the Royal Society, it was evidently so close to that of Tennant that a man with the intelligence and knowledge of Marcet could suggest in gossip to Berzelius that Davy must have known about it (9). Davy always denied this and later was specifically exonerated by a senior Committee of the Royal Society. Moreover, he proceeded to contribute a stroke of genius that was entirely his own. He suddenly realized that the powers he was seeking were resident in the orifice of the tube as much as in the length, and therefore, if he could obtain a honeycomb of orifices, he would get his results without any tubes. From that it was no step at all to the use of gauze and the Davy Lamp was invented.

It seems strange that such an obvious piece of brilliance should be challenged by supporters of the old tube idea, but this did occur. The main opponent was a most unlikely character-a local colliery-hand who had helped his father to stoke the pit-engine and in the intervals taught himself to read. Then someone lent him the books ofBoulton and Watt and he began to have ambitions. These were not without foundation, since it was not long before he burst into history as the world's first railway engineer-for his name was George Stephenson (35). His miner's lamp took its air-feed through capillary tubes but, of course, compared with Davy's it was heavy and inefficient and had no chance. Davy complained about Stephenson's claims for priority to the President of the Royal Society, who appointed a high- ranking committee to enquire into the matter, of which Wollaston was a member. This rejected Stephenson's claims and said: 'That Sir Humphry Davy not only discovered, independently of all others and without knowledge of the unpublished experiments of the late Mr Tennant on Flame, the prin- ciple of the non-communication of explosions through small apertures, but that he has also the sole merit of having first applied it to the very important purpose of a Safety-lamp.' (34)

Early in September 1814 Tennant set off on another visit to France and toured the southern provinces. He was most interested in the beauty of the scenery and the poverty in the towns. His joy in the former is reflected in his words: 'The country is the most rich and picturesque that can be imagined-



9o

after passing the mountains a new world appears-the houses of low pitched roofs like those in Poussin and Claude-following the Saone, its mountainous banks, studded with country houses, almost buried in the rich vegetation of figs, mulberries, vines and pomegranates, exceed all anticipation' and so pour out the reflections from a gentle mind sunning itself in the South. At Montpelier he met Berard, the successor of Chaptal and Berthollet, and then took in hlis stride the Pont du Gard and the Hermitage vineyards at Tain, where 'nothing can be more beautiful than the gold colour of the vine-covered hills'. He reached Paris in November and lingered there till February. Bad weather delayed his Channel crossing and on the afternoon of the 22nd he proposed to a fellow-traveller, the Baron von Bulow, a ride on horseback out from Boulogne to Napoleon's column. The story of what followed has been told many times (2, 3, 8, 13) and need not be repeated in full here; it will suffice to say that Tennant, crossing a weakened wooden bridge was thrown from his horse into the ditch below and received injuries which proved fatal within the hour. He died in the hospital at Boulogne and was buried in the public cemetery there (later known as the Cimetiere de l'Est). A gravestone was erected by his friends, bearing a simple Latin epitaph written by his Cambridge friend, John Heys (i). The stone was still standing and the epitaph legible in July I9II, when the latter was copied by Mr G. F. B. Tinley (36):

SMITHSON TENNANT Universitatis Cantabrigiensis Chemiae Professor, in Angliam itinere scientiae causa perfecto rediturus, in vicinis hujus urbis agris casu infelici mortem obiit

XXII Febr. MDCCCXV.

He never married, saw little of his relatives and, characteristically, made no will. Letters of administration of his estate were taken out in April I9I5 by the Rev. Edward Tennant, son of his father's brother, and Alice Pryme, daughter of his mother's sister. The value was o5000 (37).

It becomes more and more certain that no portrait of Tennant exists. He must have had a strong aversion to the idea. His great Cambridge friend, Sir Busick Harwood, decorated his rooms at Emmanuel with a series of miniatures, painted by the well-known miniaturist Silvester Harding, portraying many of the Emmanuel men of his period. This collection is still extant in private hands, but Tennant is not there. The friendship between the two men was very strong and, as we have seen, they migrated together from Christ's to Emmanuel. It seems obvious that Tennant must have been



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invited but declined. The best we can do, therefore, is to call up our own picture from Whishaw's words, which tell us that 'he was tall and slender, with a thin face and light complexion, of striking and agreeable appearance, with expressive features and strong marks of intelligence; several persons have been struck with a certain degree of resemblance in his countenance to the well-known portrait of Locke'.

Whishaw had great admiration for the quality of his mind and character. His perception was acute and he could analyze an argument in an instant, presenting a simple and accurate summary of the points involved almost before his hearers had absorbed the question. On these occasions, too, he was absolutely calm and unruffled, and was able quietly 'to convince the unprejudiced and to disconcert or silence his opponents'. Then also he had a great gift of imagination, which endowed him with a wide tolerance. It is noticeable, for instance, that he appears never to have involved himself with either of the extremes of politics, but to have been what used to be called 'left of centre'-most of his friends were Whigs, but he never seems to have prosecuted differences with the Tories and he was certainly as welcome at Lansdowne House as he was at Holland House. Even the French Revolution never moved him to polemics and he seems to have understood throughout the fundamental principles involved in it.

The enquiring nature of his mind was best expressed in his scientific work and in the publications in which he reported it. Here is disclosed a punctilious accuracy in interpreting what the keen perception had disclosed. And the subsequent expression of it is succinct in its economy of words, most of which have not more than two syllables, and equally economical in the development of its very clear logic.

These positive qualities of his mind were accentuated and developed by the keen pleasure which he derived from reading and the fine arts. In literature Whishaw confines himself to mentions of Virgil, Milton and Gray (someone else not unexpectedly adds Horace) among the poets and Rousseau and Pascal in prose. With painting, we have already learned that Tennant appreciated the delicate art of Claude and Poussin as well as the magnificence of Raphael; and next we are told that in music his favourites were HandeI and Pergolesi. Something has already been said about his intense interest in the civilizations and art of Asia, which he cultivated through his friendship with the explorer Browne. Perhaps his off-handed treatment of the other explorer Burchardt was connected with the fact that the latter's province was West Africa, where there was in those days nothing but jungle and the trail of Mungo Park.



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So much for a short and incomplete view of the positive qualities of this many-sided and most friendly man, and on the other side of the account there appears to be nothing to record except a single fault. Deep down in him he was impatient, but he did his utmost to prevent this from showing itself except under circumstances where he thought it did not matter. First, he was impatient with order. At Cambridge the chaos in his rooms was a by-word; and there is the well-known story of the packing of his luggage for ajourney to Paris by dumping the contents of two drawers into his breakfast table-cloth and tying it up like a laundress's bundle (13, 38). Yet in his scientific work all his faculties were under a discipline so strong that the clarity and economy of it are outstanding. Second, he was impatient with the conventions. In his laboratory and on his farm he wore clothes that were old, worn and untidy. But there is no hint that he ever attended dinners in College or with The King of Clubs other than most impeccably dressed. Next, he was impatient with people who did not interest him, like Burchardt. But on the other hand we have the story of the Empress Catherine's Russian and of his own unfortunate steward (I3, 6). He was impatient, too, with organiza- tion and method. His mind was a whirl of pieces of brilliant ideas, likely conjectures and ingenious reasonings. He could not be bothered to pursue any of them to an end, but who knows what valuable effect their presence may have had on the other projects that did pass through his mind to a conclusion? It must be fairly certain that they did not all perish in vain. Then again, after finishing his scientific work, he was often impatient about the need to write it up and publish it. His work on the double evaporation was not published until 30 years after it was done and even that on the diamond seems to have been delayed by at least eight years. His eager ideas (3) about writing, at one time a textbook of political economy, at another a life of Priestley, at still another a book on the principles of the French Revolution, never came to anything and he died in face of a large programme of unfinished work. All these oddities could come from a deep-seated im-

patience arising from on the one hand the circumstances of his childhood, and on the other from the personal affluence which removed some of the urges and disciplines that govern the lives of the less fortunate. Early signs of it are clearly apparent in the story of Black's breakfast table, and that it was a fault of temperament and not of character is shown by its accentuation, to which Whishaw frequently draws attention, in his periods of bad health, when there was added to it the normal lassitude of sickness. Whishaw com- plains about it, but Whishaw was patronizing and censorious; Tennant must often have been impatient with him-but Whishaw would stick like a



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limpet. In the end he makes amends in a gracious epitaph: 'His merits were most conspicuous in the intercourse of social life. His amiable temper, and unaffected desire of giving pleasure, no less than his superior knowledge and talents, had rendered him highly acceptable to a numerous and distinguished circle of society, by whom he was justly valued and is now most sincerely lamented.'

Undoubtedly the death of such a man at the early age of 53 was a great tragedy and the loss to both social and scientific progress must have been great. Moreover, it is not only a question of what that mind might have achieved by direct enquiry and experiment, but also of what the free expression of ideas based on the gifts that have been outlined would have fostered and cultivated in the minds of the galaxy of brilliant people whom it moved and who were so ready to accept its lead.

REFERENCES

(Note: Most of the unnumbered quotations are derived from No. 2) (I) Lady Seymour, The 'Pope' of Holland House. London, 1906. (2) John Whishaw, Annals of Philosophy (Thompson), 1816, 6, i-I; 8I-I0o. (3) John Whishaw, Some Account of the late Smithson Tennant Esq. F.R.S., Professor of

Chemistry in the University of Cambridge. London, I8I5. (4) A. E. Wales, Life and Work of Smithson Tennant. Thesis, 1940 (Brotherton Library,

University of Leeds). (5) Works and Correspondence of David Ricardo. Edited by P. Sraffa. Cambridge, 1952,

6, page 244. (6) T. Thomson, The History of Chemistry. London, I83I. Pages 232-240. (7) A. Harden, The Dictionary of National Biography. Article, 'Smithson Tennant'. (8) Mary Elvira Weeks, The Discovery of the Elements. Detroit, I956. Pages 436-440. (9) A. E. Wales, 'Smithson Tennant, I76I-I815.' Nature (Lond.), 192, 1224-1226.

30 December I96I. (Io) J. Mountain, History of Selby. York, i800. (ii) By courtesy of the Keeper of the Records, St. John's College, Cambridge. Also J. and

J. A. Venn, Alumni Cantabrigienses, and the Sedbergh School Register. Leeds, I895 and I909.

(12) Parish Registers of Selby, 1729-1763. Department of MSS. British Museum. (13) K. R. Webb, 'Smithson Tennant, I76I-I8I5.' Journal of the Royal Institute of Chemistry,

1961, 85, 432-434. (I4) L. F. Gilbert, 'W. H. Wollaston MSS. at Cambridge', Notes and Records of the Royal

Society of London, 1952, 9, 311-332. (I5) J. Robison, Lectures on the Elements of Chemistry by Dr Joseph Black, 1803, 2, page 699. (16) Sir William Ramsay, The Letters of Joseph Black, 1918, page I32. (17) The Parlour Books of Emmanuel College, Cambridge. (I8) Phil. Trans., 1791, I82.

(I9) Phil. Trans., I797, 123.

(20) Phil. Trans., I797, 219.



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(21) Phil. Trans., 1799, 305. (22) Phil. Trans., 1802, 398. (23) H. V. Collet Descotils, Annales de Chimie, 1803, 48, 153-I76. (24) N. L. Vauquelin, Annales de Chimie, 1804, 89, 50o-I8I; 225-250.

(25) Phil. Trans., 1804, 94, 411-418. (26) W. H. Wollaston, Phil Trans., 1804, 94, 419-430; i805, 95, 316-330. (27) W. H. Wollaston, Phil. Trans., 1829, 119, I-8.

(28) Nicholson's Journal, I806, 14, I35. (29) Transactions of the Geological Society, 1811, I, 389-390. (30) Any publication has not so far been traced. (3I) Phil. Trans., 1814, 578. (32) Phil. Trans., 1814, 587. (33) Minutes of Council (Royal Society), 8, 13 December I8Io to 28 March 1822.

(34) J. A. Paris, Life of Sir Humphry Davy (in two volumes). London, I831, 2, pages 77-131. (35) Encyclopaedia Britannica, 1929. Article, 'George Stephenson'. (36) Copy in the Great Card Index of the Society of Genealogists, London. (37) Admon Book, I8I5. Somerset House, London. (38) Henry Gunning, Reminiscences of the University-of Cambridge. London, 1854, 2, pages

59-62.

Also consulted:

John Peile, Biographical Register of Christ's College, Cambridge, I9I0-I913, pages 316-317. The Gentleman's Magazine, I815, I, 28I.



smithson tennant, f.r.s. (1761-1815)

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