# Dictionary of National Biography, 1885-1900/Young, Thomas (1773-1829)

​YOUNG, THOMAS (1773–1829), physician, physicist, and Egyptologist, the eldest son of Thomas Young of Milverton, by his wife Sarah, daughter of Robert Davis of Minehead, Somerset, was born at Milverton on 13 June 1773. His father owned a considerable amount of property in the neighbourhood, and both parents were members of the Society of Friends.
Up to the age of seven he resided with his grandfather, an admirer of the classics, who encouraged in every way the extraordinary precocity his grandson began to display. At two years of age he could read with fluency, and before he commenced Latin, at six, could repeat from memory Goldsmith's ‘Deserted Village’ and many other poems. At seven he was sent to a ‘miserable boarding-school’ near Bristol, where he was taught nothing. After a year there he returned to Milverton, and read science books borrowed from a neighbour named Kingdon. When nearly nine he was sent to a good school at Compton, Dorset, kept by a Mr. Thompson. There he studied Latin, Greek, mathematics, and natural philosophy, and was taught drawing and turning by one of the ushers, Josiah Jeffrey, a man of great mechanical skill. After four years at this school he returned to Milverton, where he continued his studies, taking up Hebrew, Chaldee, Syriac, and Persian, and began making optical instruments. During this period he displayed great powers of acquisition, and a determination to master difficulties which remained one of his characteristics through life. In 1787, when only fourteen, he became classical tutor to Hudson Gurney [q. v.], grandson of David Barclay [q. v.] of Youngsbury, Hertfordshire, and spent the next five years of his life at Youngsbury pursuing his studies and acquiring a thorough knowledge of Latin and Greek, and a considerable acquaintance with Hebrew, Chaldee, Arabic, Syriac, Persian, French, Italian, and Spanish. During this interval, when about sixteen, he was at ​tacked by an illness thought to be consumption, and this led to his extraordinary abilities being brought to the notice of Richard Brocklesby (1722–1797) [q. v.], an uncle of his mother, who was called in and succeeded in restoring him to health. From this period he visited Brocklesby in London each winter, and at his house met with most of the distinguished literary men of the day, and when eighteen was recognised by them as a classical scholar of no mean order.
In 1792 Young took lodgings in Little Queen Street, Westminster, and commenced studying for the medical profession. He first attended the lectures of Matthew Baillie [q. v.], William Cumberland Cruikshank [q. v.], and John Hunter (1728–1793) [q. v.], and then, in 1793, entered for a year as a student at St. Bartholomew's Hospital. On 30 May 1793 he read a paper before the Royal Society, in which he attributed the accommodating power of the eye to a muscular structure of the crystalline lens. This was published in the ‘Philosophical Transactions’ of the society, and led to his election, on 19 June 1794, as a member of the society. In the autumn of that year he proceeded to Edinburgh, where it had been decided he should continue his studies, and spent the winter there, attending lectures by James Gregory (1753–1821) [q. v.], Andrew Duncan [q. v.], and Joseph Black [q. v.], and studying German, Spanish, and Italian. During this time he dropped the outward characteristics of a ‘Friend,’ mixed largely in society, to which his uncle's position and his own reputation gave him an entrance, and learnt to play the flute, to sing, and to dance. In the summer of 1795 he made a tour of the highlands, in the course of which he visited the Duke of Gordon at Elgin, and the Duke of Argyll at Inverary. In October he went to Göttingen, to continue his studies under Arnemann, Richter, Blumenbach, and Lichtenberg. There he learnt horsemanship and devoted considerable attention to music and art. On 30 April he passed the examination, and his dissertation ‘De Corporis Humani viribus conservatricibus’ having been approved, he was created doctor of physic on 16 July 1796. Leaving Göttingen a few weeks later, he travelled mainly on foot to Dresden, where he remained a month to study the art collection, and then continued his journey by Berlin and Hamburg to London.
In accordance with the wishes of Brocklesby he entered as a fellow-commoner at Emmanuel College, Cambridge, on 18 March 1797. The Rev. Robert Towerson Cory, shortly afterwards master of the college, was one of his tutors, but he was never required to attend the common duties of the college. He was known as ‘Phenomenon Young,’ and associated on terms of equality with the fellows, but complained of the barriers which custom imposed on his free intercourse as a student with the more distinguished members of the university. On the sudden death of Brocklesby, on 13 Dec. 1797, he succeeded to his uncle's house in Norfolk Street, Park Lane, London, his library, pictures, and 10,000l. He continued, however, to reside at Cambridge in term time, entered as much as possible into general society, and formed friendships with many distinguished scholars, e.g. (Sir) William Gell [q. v.], Edward Dodwell [q. v.], Matthew Raine [q. v.], (Sir) Isaac Pennington [q. v.], and John Cust (Earl Brownlow) (1779–1853), which he retained in after life. In the summer of 1798 he carried out some experiments on sound and light, afterwards communicated to the Royal Society, which formed the starting-point for his subsequent theory of ‘interference.’ After spending part of 1799 in attending the London hospitals, he established himself in practice as a physician at 48 Welbeck Street, London. He continued, however, his contributions to literature and science, sometimes under his own name, sometimes anonymously, to avoid the charge of allowing other studies to take his attention from the duties of his profession.
In July 1801 he was appointed professor of natural philosophy at the Royal Institution, editor of the ‘Journals,’ and superintendent of the house, with a salary of 300l. and rooms. Between January and May 1802 he delivered thirty-one, and next year sixty lectures, which he afterwards (1807) published. His lectures displayed the extraordinary width of his acquaintance with his subjects, but were too didactic and condensed for the popular audiences to whom they were delivered (Paris). He resigned the professorship in July 1803, as his friends considered the duties interfered with his prospects as a physician. In 1802 he was appointed foreign secretary to the Royal Society, and held that office till his death. In March 1803 he was admitted at Cambridge to the degree of M.B., and on 2 July 1808 took the degree of M.D.
The summer of 1805 was spent professionally at Worthing, then a fashionable watering-place, and the visit was repeated annually till 1820, Young having in 1808 acquired a house there.
He became a candidate of the College of Physicians on 30 Sept. 1808 and fellow on 22 Dec. 1809. He was censor in 1813 and ​1823, and Croonian lecturer to the college in 1822 and 1823. During the winters of 1809 and 1810 he delivered at the Middlesex Hospital two courses of lectures on medical science and the practice of physic, afterwards (1813) embodied in his work on medical literature. Like his lectures at the Royal Institution, they were too condensed to attract many students, and were only sparsely attended. On 24 Jan. 1811 he was elected physician to St. George's Hospital, London, a position he retained till his death. In 1814, at the request of the admiralty, he reported on a proposed change in the method of building ships (Phil. Trans. 1814). During the same year he became a member of a committee of the Royal Society appointed at the request of the secretary of state to investigate the risk attending the proposed general introduction of gas in London. The results of the experiments made by the committee removed all fear of danger. In 1816 he was appointed secretary of a commission for ascertaining the length of the seconds pendulum. This commission subsequently recommended the establishment of the present ‘imperial gallon’ of ten pounds of water.
In November 1818 Young was appointed superintendent of the ‘Nautical Almanac’ with a salary of 100l., and secretary of the reconstituted board of longitude, with a further salary of 300l. per annum. His opinion that the ‘Nautical Almanac’ should, as in the past, supply only information of importance in navigation, brought him into conflict with many astronomers of the day, who wished it to be carried out on the more liberal scale of the ‘Ephemerides’ published abroad. When in 1828 the board of longitude was dissolved, and the admiralty assumed its functions, Young, as superintendent of the ‘Nautical Almanac,’ was appointed an adviser to the admiralty, and the agitation for reform was resumed. His death put an end to the contest, and on the report of a committee of the Astronomical Society appointed to consider the matter, the ‘Nautical Almanac’ took its present form.
In 1814 Young retired from practice as a physician, having been appointed inspector of calculations to the Palladium Insurance Company at a salary of 500l. per annum. Within the next two years he published several papers dealing with life assurance.
During two visits to Paris in 1817 and 1821 he had met most of the distinguished French scientists, and was elected on 6 Aug. 1827 one of the eight foreign members of the French Academy of Science. In 1828 he visited Paris on his way to Geneva, where his strength commenced to show signs of decay. He sank gradually and died on 10 May 1829, at his house in Park Square, to which he had removed in 1826. He was interred at Farnborough, Kent. He left no issue.
He married, on 14 June 1804, Eliza (1785–1859), second daughter of James Primrose Maxwell of 69 Harley Street, London, and Tubbendens, Kent. The marriage was a remarkably happy one, and the relations between Young and his wife's family were always most affectionate. Mrs. Young's brother was Captain George Berkeley Maxwell, R.N. (1791–1854).
Young has been justly called ‘the founder of physiological optics’ (Tscherning). He was the first to prove conclusively that the accommodation of the eye for vision at different distances was due to change of curvature of the crystalline lens (Phil. Trans. 1793). His opinion that the lens itself was muscular has, however, not been confirmed by more recent work. His memoir ‘On the Mechanism of the Eye’ (ib. 1801) contained the first description and measurement of astigmatism, and a table of optical constants of the eye in close agreement with modern determinations. He first explained colour sensation as due to the presence in the retina of structures which respond to the three colours, red, green, and violet respectively (Lectures, i. 139, 440), and colour blindness as due to the inability of one or more of these structures to respond normally to stimulus (ib. ii. 315). Young's theory has been supported and extended by Helmholtz; and although a rival theory due to Hering is regarded with favour by many physiologists (Foster), there are phenomena unfavourable to that theory (Tscherning; Burch).
Of other contributions connected with his profession two of the most noteworthy are the Croonian lecture to the Royal Society ‘On the Functions of the Heart and Arteries’ (November 1808, Phil. Trans.), in which the laws regulating the flow of blood through the body are clearly stated; and its predecessor, ‘Hydraulic Investigations’ (May 1808, Phil. Trans.), on which it depends. His work on ‘Medical Literature’ (1813) was the most complete of its kind for many years, and reached a second edition (1823); while his ‘Practical and Historical Essay on Consumptive Diseases’ (1815) was a condensed account of all that was then known on the subject.
When Young began to write on physical optics, the wave theory of light (Huyghens, Traité de la Lumière, 1690) had made little headway against its rival the emission theory. Young supported the wave theory in his ​‘Experiments on Sound and Light’ (January 1800, Phil. Trans.), and next year (Nicholson's Journal, August 1801) extended the conclusions he had drawn in that paper ‘on the coalescence of musical sounds’ to the ‘interference’ of light. A more detailed account of his doctrine of ‘interference’ and its applications appeared in his brilliant memoir ‘On the Theory of Light and Colours’ (Bakerian Lecture, November 1801, Phil. Trans.), which marks an epoch in the history of the subject. In it he showed that the colours of thin and of thick plates, of striated surfaces, and those seen at the edge of the shadow of an obstacle, could all be explained by the interference of light undulations which had traversed different paths, and concluded with the proposition ‘Radiant light consists of undulations of the luminiferous ether.’ Other phenomena were explained in two subsequent papers (July 1802, Phil. Trans.; Bakerian Lecture, November 1803, Phil. Trans.) The vital importance of Young's work was, however, not understood, and the three memoirs met with severe and unjust criticism at the hands of Henry Brougham [q. v.] in the ‘Edinburgh Review’ (Nos. ii. and ix. 1803). The critic could find in them ‘nothing which deserves the name either of experiment or discovery,’ considered them ‘destitute of every species of merit,’ and admonished the Royal Society for printing such ‘paltry and unsubstantial papers.’ Young's masterly reply was published in the form of a pamphlet (London, 1804), which, remaining almost unknown, did nothing to counteract the effect produced by these unfortunate assertions; and the principle of interference remained unnoticed till fourteen years later it was rediscovered by Fresnel.
A further advance was made by Young in 1809, when he showed (Quarterly Review, ii. 344) that the variation of the index of refraction of a uniaxal crystal, which the emission theory had been unable to explain satisfactorily, was on the wave theory a simple consequence of the elasticity of the crystal being different in different directions. The idea thus introduced was developed by Fresnel into a complete theory of double refraction (1821).
Dispersion in transparent media was explained by Young (Theory of Light and Colours, Prop. vii.) as due to the oscillations of the material particles set in motion by the ether vibrations, affecting the latter to an amount depending on their frequency. This explanation has been extended by Sellmeyer, Helmholtz, and others into complete theories of dispersion for absorbent media.
The phenomena exhibited by polarised light had proved too difficult of explanation by either the emission or the wave theory, although Young had suggested (Quarterly Rev. April 1814) that the colours produced by the passage of polarised light through crystalline plates were due to interference of the two polarised rays into which the crystal divided the incident light. When in 1816 Arago and Fresnel showed that two rays polarised at right angles to each other would not interfere, Young pointed out immediately that this implied that the vibrations of light were transverse to the ray. Next year he showed (‘Chromatics,’ Encycl. Brit. 6th edit.; Works, i. 335) that the law of Malus for the intensities of the two rays into which a crystal divides polarised light incident on it, was a consequence of the transverse nature of the vibrations, and in a few years, principally by the work of Fresnel and Arago, most of the phenomena of polarisation had been explained on the wave theory.
In his ‘Essay on the Cohesion of Fluids’ (December 1804, Phil. Trans.) Young gave in non-mathematical language the theory of capillary action soon after and independently (1805) brought forward by Laplace, and now known by his name. In this essay Young for the first time accounted on physical grounds for the constancy of the angle of contact of a solid and a liquid.
He was the first to use the term ‘energy’ for the product of the mass of a body into the square of its velocity, and the expression ‘labour expended’ (work done) for the product of the force exerted on a body into the distance through which it is moved, and to state that these two products were proportional to each other (Lectures, i. 78–9). He introduced absolute measurements in elasticity by defining the ‘modulus’ (Young's modulus) as the weight which would double the length of a rod of unit cross-section to which it was hung (Lectures, i. 137). He agreed with Rumford [see Thompson, Benjamin], Pictet, and Sir Humphry Davy [q. v.] as to the impossibility of any ‘material’ theory of heat (November 1801, Phil. Trans.), and held that it consisted of vibrations of the particles of bodies, ‘larger and stronger than those of light’ (Lectures, i. 654).
Young's ‘Theory of the Tides,’ given first in his ‘Lectures’ (p. 576), then in ‘Nicholson's Journal’ (1813), and more completely in the ‘Encyclopædia Britannica’ 6th edit. (1823) (Works, ii. 291), explained more tidal phenomena than any other theory till (Sir) George B. Airy's article on ‘Tides and Waves’ appeared in the ‘Encyclopædia Metropolitana,’ vol. v. (1844).
Young contributed to the supplement to ​the ‘Encyclopædia Britannica’ (6th edit.) several scientific articles containing important results of his own—e.g. ‘Bridge,’ ‘Cohesion,’ numerous biographies, e.g. Hon. Henry Cavendish [q. v.], Sir Benjamin Thompson, count von Rumford, and Coulomb; and to Brand's Journal several articles on geodetic and astronomical subjects.
Many attempts had been made during the eighteenth century to interpret the hieroglyphic inscriptions found on Egyptian remains, but all had failed. It had been conjectured, however, that some at least of the characters represented sounds, and that those enclosed in an oval line represented proper names. When, in 1799, a tablet was discovered at Rosetta, at the mouth of the Nile, with a decree of the priests inscribed on it in hieroglyphic (sacred), enchorial (cursive), and Greek characters, it was seen that the Greek might afford a clue to the interpretation of the Egyptian inscriptions. Silvestre de Sacy first interpreted three proper names in the enchorial text, and Akerblad and Champollion claimed to have interpreted the whole of it, but up to 1814 neither had published an interpretation. In October of that year Young communicated to De Sacy a complete translation of the enchorial (or, as it is now called, demotic) text, and in 1815 published (Archæologia, vol. xviii.) a comparison of the translations of the demotic and Greek texts. In a letter to De Sacy (3 Aug. 1815) he announced his discovery that the demotic characters were not all alphabetic, but that some were symbolic. By next year he had found that the enchorial characters were derived from the hieroglyphic, and in 1818 he wrote for the ‘Encyclopædia Britannica’ the justly celebrated article ‘Egypt,’ in which he pointed out the phonetic character of the hieroglyphs in the ovals, which he found to be royal names. From the name Ptolemy (Ptolemaos), which occurred several times in the Rosetta inscriptions, he obtained the hieroglyphs now transliterated p, t, l, m, y, s, and to which he assigned the values p, t, ole, m, i, os, respectively, and from other portions f, to which he gave the correct value. His analysis of an oval containing the name of Berenice in an inscription at Karnak was not so happy, only one letter, n, being correct. In addition to the beginnings of a hieroglyphic alphabet, Young gave in his article a hieroglyphic vocabulary of about two hundred signs not alphabetic, most of which have been confirmed by more recent research.
In 1821 Champollion, who had continued his study of Egyptian inscriptions, published a work, ‘De l'Ecriture Hiératique des Anciens Egyptiens,’ in which he stated that the hieroglyphs were ‘signs of things and not of sounds.’ Before another year had passed he changed his opinions, and, applying Young's method to an oval containing the name Cleopatra, obtained the hieroglyphs for k and r, and an alternative one for t. From this point his progress was rapid, and his memorable work ‘Précis du Système Hiéroglyphique’ appeared in 1824. The parallel, but virtually independent, investigations of the two scholars are elucidated by Renouf in ‘Proceedings of the Society of Biblical Archæology’ (xix. 188 et seq.).
In November 1822 Young discovered that an ancient Greek manuscript brought by G. F. Grey of Oxford from Thebes was a translation of a demotic papyrus in the Paris collection, which he was at the time studying. It related to the sale by the priests of the offerings made to the gods on behalf of certain mummies, and enabled many new facts with respect to the demotic character to be established. These Young made known, together with his original work on hieroglyphs and the advances since made by Champollion, in his ‘Account of some Recent Discoveries in Hieroglyphical Literature and Egyptian Antiquities’ (1823). He kept up for the rest of his life a correspondence on Egyptian subjects with Sir W. Gell and Champollion, and was engaged on an Egyptian dictionary at the time of his death.
Young contributed to the ‘Quarterly Review’ several archæological, philological, and critical articles; and to the supplement to the ‘Encyclopædia Britannica’ (6th edit.) the article ‘Language,’ and several lives of scholars—e.g. Richard Porson [q. v.]
Young, though not quite so tall as represented in his portrait, was well formed in person, and took great delight in bodily exercise. ‘His language was correct and his utterance rapid.’ His temper was remarkably even, a consequence probably of his early training, and his domestic life singularly happy. He ‘was emphatically a man of truth,’ ‘could not bear … the slightest degree of exaggeration,’ was ‘in all the relations of life upright, kind-hearted, generous,’ and ‘entirely free from either envy or jealousy’ (Gurney). He was ‘accustomed to reciprocate visits with the best society,’ ‘and was always ready to take his part in a dance or a glee, or to join in any scheme of amusement calculated to give life and interest to a party’ (Peacock). His success as a physician was not so great as might have been expected. He practised in ​an age when ‘vigorous measures’ were thought the only ones worthy of a great physician, and his careful study of symptoms in order to arrive at the cause of a disease was put down by his contemporaries to weakness, and the acknowledged success of his treatment was unable to remove this impression. Sir Benjamin Brodie [q. v.] considered that Young ‘was either not fitted for a physician, or was too engrossed in other pursuits.’ Young himself (1811) said: ‘I have been fortunate enough … to acquire a pretty good proportion of those things for which affluence is principally desired … but I am not the more in love with my profession.’
Many of Young's writings have been characterised as obscure. While the charge has some foundation if confined to his earlier, it is unjust to extend it to his later works. The intellectual isolation of his early years, and the ease with which, carrying out his motto, ‘What one has done another can do,’ he surmounted difficulties, rendered him ignorant of the limitation of the powers of others, and he thought it necessary to give only a few steps of his argument to render the whole course of it clear. His contempt for analytical processes, engendered no doubt by the torpid condition of mathematical studies at Cambridge in his time, made him cut down all algebraic work to a minimum, and his mathematical papers are most open to the charge of obscurity. His lectures are, on the contrary, a ‘mine of good things happily expressed’ (De Morgan).
His colleague at the Royal Institution said of him: ‘He was a most amiable and good-tempered man … of universal erudition, and almost universal accomplishments. Had he limited himself to any one department of knowledge, he must have been the first in that department. But as a mathematician, a scholar, a hieroglyphist, he was eminent, and he knew so much that it was difficult to say what he did not know’ (Davy).
No opinion expressed in recent times is more worthy of attention than that of Helmholtz, who in the vast extent of his knowledge and the importance of his contributions to science so much resembled Young. He says: ‘He was one of the most clear-sighted men who have ever lived, but he had the misfortune to be too greatly superior in sagacity to his contemporaries. They gazed at him with astonishment, but could not always follow the bold flights of his intellect, and thus a multitude of his most important ideas lay buried and forgotten in the great tomes of the Royal Society of London, till a later generation in tardy advance remade his discoveries and convinced itself of the accuracy and force of his inferences.’
Young published the following works:
* ‘A Course of Lectures on Natural Philosophy and the Mechanical Arts,’ 1807, 2 vols. 4to; new ed., edited by Professor Kelland, 1845, 2 vols. 8vo.
* ‘An Introduction to Medical Literature, including a System of Practical Nosology,’ 1813, 8vo; new ed., with essay on ‘Palpitations’ added, 1823.
* ‘A Practical and Historical Treatise on Consumptive Diseases,’ 1815, 8vo.
* ‘Letter of Canova and Memoirs of Visconti on the Elgin Marbles.’ Translated (anonymous), 1816, 8vo.
* ‘Elementary Illustrations of the Celestial Mechanics of Laplace,’ 1821, 8vo.
* ‘An Account of the Recent Discoveries in Hieroglyphical Literature and Egyptian Antiquities,’ 1823, 8vo.
* ‘Enchorial Egyptian Dictionary,’ appended to the ‘Egyptian Grammar’ by Henry Tattam [q. v.], 1830.
A collection of translations, ‘Œuvres Ophtalmologiques de Thomas Young,’ made and edited with great sympathy and care by Tscherning, was published in 1894.
A portrait of Young, painted by Sir Thomas Lawrence [q. v.] for Hudson Gurney, passed into the possession of Mr. J. H. Gurney, J.P., of Keswick Hall, Norwich. A copy by Henry Perronet Briggs [q. v.] was presented by Hudson Gurney to the Royal Society in 1842, and is now in the society's rooms at Burlington House. A second copy by Thomas Brigstocke [q. v.] was presented to the governors of St. George's Hospital by friends and pupils of Young in 1851, and now hangs in the board-room. A third copy by Minna Tayler (1884) hangs in the combination room at Emmanuel College, Cambridge; and a fourth by Briggs passed to the possession of A. E. Young, esq. An engraving by George Raphael Ward from Lawrence's portrait forms the frontispiece of Peacock's ‘Life of Young.’ Others form the frontispieces of Pettigrew's ‘Life of Young,’ Tyndall's ‘Light,’ and Tscherning's ‘Œuvres Ophtalmologiques.’ A memorial tablet with profile medallion by Sir Francis Chantrey [q. v.], and inscription by Gurney, is to be seen in Westminster Abbey, and another memorial is in the Shire Hall at Taunton.
C. H. L.