# Popular Science Monthly/Volume 5/July 1874/Sketch of Dr. Thomas Young

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Dr. THOMAS YOUNG.
* SKETCH OF DR. THOMAS YOUNG.
ON a slab in Westminster Abbey, surmounted by a profile medallion, the work of Chantrey, there is the following inscription:
SACRED TO THE MEMORY OF
THOMAS YOUNG, M.D.,
FELLOW AND FOREIGN SECRETARY OF THE ROYAL SOCIETY, MEMBER OF THE NATIONAL INSTITUTE OF FRANCE; A MAN ALIKE EMINENT IN ALMOST EVERY DEPARTMENT OF HUMAN LEARNING. PATIENT OF UNINTERMITTED LABOR, ENDOWED WITH THE FACULTY OF INTUITIVE PERCEPTION, WHO, BRINGING AN EQUAL MASTERY TO THE MOST ABSTRUSE INVESTIGATIONS OF LETTERS AND OF SCIENCE, FIRST ESTABLISHED THE UNDULATORY THEORY OF LIGHT, AND FIRST PENETRATED THE OBSCURITY WHICH HAD VEILED FOR AGES THE HIEROGLYPHICS OF EGYPT.
The subject of this eulogy was one of the most remarkable men in the annals of British science and literature—according to Prof. Tyndall, the greatest man of science that had appeared since Newton; and, as his biography has never been republished in this country, a brief sketch of his life will be fresh and instructive to many.
Thomas Young was born in 1773, and died in 1829. He was the eldest son of ten children. His parents were both members of the Society of Friends, and strict observers of the principles of their sect, in which their children were carefully educated. Dr. Dalton, the eminent English chemist, was also of Quaker parentage and education; but, while he continued through life to retain his membership of the denomination and to conform to its principles, Dr. Young held the tenets and conformed to the observances of the Society only during his youth. He was a very precocious child. At two years of age he could read with fluency, and had read the Bible twice through before he was four years old. At six years of age he could repeat Goldsmith's "Deserted Village," and had previously begun his Latin grammar. At seven years of age he was sent to a miserable boarding-school, but the next year at the house of a friend he came across a "Dictionary of Arts and Sciences," which he perused with intense interest, and also got instruction in the use of some mathematical and philosophical instruments. When nine years old he was sent to another school, where he remained four years, and made great proficiency in classics, mathematics, and natural philosophy. He also learned the principles of drawing, the art of book-binding, the construction of ​microscopes, telescopes, and electrical machines, and the use of the lathe. In an autobiographical sketch, he says that, after returning home from this school, he devoted himself almost entirely to the study of Hebrew, and to the practice of turning and telescope-making. He borrowed and studied with great diligence the Chaldee, Syriac, Samaritan, and Persian grammars, and, having got hold of the Lord's Prayer in a hundred different languages, was greatly interested. At fourteen years of age Young became tutor to Mr. Hudson Gurney, who was a year and a half older, and who continued his friend through life, and wrote a biography of him. He wrote a beautiful hand, and, when once requested by a friend of his uncle, Dr. Brocklesby, an eminent London physician, to exhibit a specimen of his handwriting, he wrote a sentence in fourteen different languages. His precocity reminds us of that of J. S. Mill, but it had a far more spontaneous and varied exercise. He went on with his mathematical, botanical, and entomological studies with great ardor, but he was left to entire freedom in their pursuit, and believed that "whoever would arrive at excellence must be self-taught;" and that there was "in reality very little that a person, seriously and industriously disposed to improve, may not obtain from books with more advantage than from the living instructor." Upon this principle, as his biographer remarks, he was self-taught. "He read nothing hastily or cursorily, and his memory was so tenacious that he never forgot what he had once mastered. He wrote exercises and composed in the languages in which he studied. His journals were written in Latin, and his criticisms on French authors in French, and on Italian authors in Italian. His mathematical studies were carried on in a similar manner. He began the six books of Euclid on such a day, and finished them on another; and we hear no more of them. Algebra, trigonometry, and fluxions were dispatched in the same way. He read the 'Principia' deliberately through; and it appears from the remarks in his journals that he had fully comprehended them."
At nineteen years of age, in obedience to the wishes of his uncle, Mr. Young entered upon the study of anatomy and medicine, and from the outset he became an original investigator in this field, his first researches being into the structure of the eye as an optical instrument. At the age of twenty-one, the Duke of Richmond offered him the appointment of his private secretary, at $1,000 a year, and "a place at the duke's table." This he declined on the ground of Quaker scruples, and wrote to his mother that he "was not ashamed to allege his regard for the Society as a principal reason for not accepting the proposal.... This event in his life led him, no doubt, to consider how far his position as a Quaker might interfere with his future prospects. He had hitherto adopted their garb and phraseology, but he now began to divest himself of these characteristics, and to mix largely with society. In Edinburgh, where he went at the close of 1794 to prosecute his medical education, he did not scruple to violate the principles of his ​sect. He spent much time at parties, both grave and gay; went frequently to the theatre in spite of the remonstrances of his friends, took private lessons in dancing and in playing on the flute."
After prosecuting his medical studies in Edinburgh, he made a thorough tour of Scotland at the close of the session of 1795, and returning to England went at once to Göttingen, "where, along with his medical studies, he took lessons in drawing, dancing, riding, and music, in all of which he made rapid progress. He was passionately fond of horsemanship, and there were no feats in that art too daring for him to accomplish."
In 1797 his uncle, Dr. Brocklesby, died, leaving him his house, library, collection of prints and pictures, and fifty thousand dollars in money, which enabled him to pursue his inquiries with greater facility, and in the beginning of 1800 he commenced the practice of medicine in London. In 1801 he was appointed Professor of Natural Philosophy in the Royal Institution of Great Britain, and he conducted its journal along with Humphrey Davy, then Professor of Chemistry. The first year he gave thirty-one lectures, and afterward sixty, which were published in 1807, in two quarto volumes, under the title of "A Course of Lectures on Natural Philosophy and the Mechanical Arts," a work which, notwithstanding its obscurity both in language and in thought, is rich in original and ingenious views, and of inestimable value to the student of physics and the mechanic arts.
It was in May, 1801. when Dr. Young was twenty-eight years of age, that, reflecting on the experiments of Newton, he was led to the discovery of a law which "appeared to him to account for a greater variety of interesting phenomena than any other optical principle that had yet been made known." This was the law of the Interference of Light, which he explained on the principle of the undulatory theory. This theory had been long before propounded by Huyghens and Hooke, but Dr. Young revived it, gave it greater precision of form, and first proved that it accounts for luminous phenomena which can be explained by no other known hypothesis. His views were developed in Nicholson's Journal for 1801, in the following propositions:
"I am of opinion," says he, "that light is probably the undulation of an elastic medium, because—
"1. Its velocity in the same medium is always equal.
"2. All refractions are attended with a partial reflection.
"3. There is no reason to expect that such a vibration should diverge equally in all directions, and it is probable that it does diverge in a small degree in every direction.
"4. The dispersion of differently colored rays is no more incompatible with this system than with the common opinion, which only assigns for it the nominal cause of different elective attractions.
"5. Reflection and refraction are equally explicable on both suppositions.
"6. Inflection is as well, and, it may be added, even much better, explained by this theory.
"7. All the phenomena of the colors of thin plates, which are in reality unintelligible on the common hypothesis, admit of a very complete and simple explanation by this supposition. The analogy which is here superficially indicated will probably soon be made public more in detail; and will also be extended to the colors of thick plates, and to the fringes produced by inflection, affording from Newton's own elaborate experiments a most convincing argument in favor of this system."
Regarding medicine as an inductive branch of philosophy, Dr. Young drew up an "Introduction to Medical Literature, including a Practical System of Nosology," which Dr. Peacock, his latest biographer, says, bears much the same relation to the medical sciences that his lectures on natural philosophy bear to the mathematical and physical sciences. It appeared in 1813, and in an Appendix he gave a sketch of animal chemistry, translated from the Swedish of Berzelius by the aid of a grammar and dictionary, without any previous acquaintance with the language.
In the field of philological exploration, Dr. Young exhibited talents of a very high order. He was especially skillful in deciphering manuscripts and inscriptions which had baffled the ingenuity of his predecessors. "The attention of Dr. Young was first devoted to hieroglyphic research by a papyrus in Egyptian characters, submitted to him in the spring of 1814, by Sir W. Rouse Boughton, found in a mummy-case in a catacomb near Thebes. The papyrus was written in cursive Egyptian characters, and Dr. Young's notice of it was appended to a communication, by its discoverer, to the Antiquarian Society. Between May and November of the same year, he analyzed the three inscriptions of the well-known Rosetta Stone, and gave a conjectural translation of the second of the three, which was added to the notice above mentioned." Champollion, the great French antiquarian, was the rival of Young in the work of unraveling the old inscriptions, and a warm controversy grew out of their respective claims which was not free from the tinge of national feeling. Both were men undoubtedly of great originality, and made their discoveries independent of each other. "Dr. Young never failed to do justice to the sagacity, the extensive learning, and the deep research of Champollion; and his own merits were nobly recognized by the countrymen of his rival, when, in 1828, they elected him one of the eight foreign associates of the Institute of France."
About the year 1810 Dr. Young took up the subject of naval architecture, and contributed important improvements to the construction of ships-of-war. In 1816 he was appointed secretary to a commission for ascertaining the length of the second's pendulum, and drew up the three reports which were made in 1819, 1820, and 1821. In 1818 he was appointed superintendent of the Nautical Almanac. He had, some years previously to this, gone into the subject of life-assurance, and worked out mathematically the formula of the value of life, and ​the laws of mortality. He wrote a great number of papers on many-subjects in the Quarterly Review and in the Encyclopædia Botanica. As the undulatory theory of light gradually made its way, being fortified in a remarkable manner by the discoveries of Fresnel, the French physicist, there grew up an increasing recognition of the claims of Dr. Young in regard to the subject. Of his distinguished merits and their ultimate recognition, Dr. Peacock remarks:
"On the 6th of August, 1827, he was elected one of the eight foreign associates of the Academy of Sciences, at Paris, in the place of Volta. The other competitors named were the great astronomers Bessel and Olbers; Robert Brown, the botanist; Sœmmering, the anatomist; Blumenbach, the naturalist; Leopold von Buch, the geologist; Dalton, the chemist; and Plana, the mathematician. This is the greatest honor that can be conferred on a man of science.
"The propriety of the selection which was made by the Institute of France, of Wollaston, Davy, and Young, as the most eminent representatives of English science in that age, was disputed by very few of their contemporaries who were capable of forming a correct opinion.
"The lapse of a quarter of a century, since the grave—within the brief space of six months—closed upon the labors of these three eminent philosophers, has somewhat changed the order in which they were classed by their contemporaries. If Young held the lowest place in the order of precedence then, he unquestionably occupies the highest now. The most brilliant achievements of Davy, whether considered singly or collectively, are probably surpassed in importance by the discovery and demonstration of the interference of light; but while the first received the prompt and unhesitating acknowledgment of the scientific world, and at once secured for their author the honors and rewards which were due to his merits, the second, even after emerging from a long period of misrepresentation and neglect, had to make its way, step by step, as it were, and with various and fluctuating fortunes, against the opposition of adverse and long-established theories, supported by the authority of the two greatest men known to the scientific history of the past and present age."
In the summer of 1827 Dr. Young's health began to decline, and in 1829 he suffered from repeated attacks of asthma, accompanied with great oppression and weakness. He sank gradually, and expired without a struggle,May 10, 1829, aged fifty-six. His disease proved to be an ossification of the aorta, which must have been in progress for many years. Every appearance indicated an advance of age not brought on by the natural course of time, but probably by unwearied and incessant labor of the mind from the earliest days of infancy. We have barely touched upon some of the points of the life of Dr. Young, and, to those who care to pursue it further, we can recommend his admirable biography by Dr. Peacock, published by Murray, of London.