Part 18

Towards the close of the year 1828, Wollaston became dangerously ill with disease of the brain. Feeling his end approaching, and being unable to write himself, he employed an amanuensis to write accounts of such of his discoveries and inventions as he was unwilling should perish with him; and in this manner some of his most important papers were communicated to the Royal Society. It is a curious fact, that, in spite of the extensive cerebral disease under which he laboured, his faculties continued unclouded to the very last. When almost at the point of death, one of his friends having observed, loud enough for him to hear, that he was unconscious of what was passing around him, Wollaston made a sign for pencil and paper, and then wrote down some figures, and after casting up the sum, returned the paper: the amount was found to be correct.

Dr. Wollaston died on the 22nd of December, 1828, at the age of sixty-two--only a few months before his great scientific contemporaries, Sir Humphry Davy and Dr. Thomas Young. He was buried in Chiselhurst churchyard, Kent. Dr. William Henry[48] gives the following summary of his character:--

"Dr. Wollaston was endowed with bodily senses of extraordinary acuteness and accuracy, and with great general vigour of understanding. Trained in the discipline of the exact sciences, he had acquired a powerful command over his attention, and had habituated himself to the most rigid correctness both of thought and language. He was sufficiently provided with the resources of the mathematics, to be enabled to pursue with success profound enquiries in mechanical and optical philosophy, the results of which enabled him to unfold the causes of phenomena not before understood, and to enrich the arts connected with those sciences by the invention of ingenious and valuable instruments. In chemistry he was distinguished by the extreme nicety and delicacy of his observations, by the quickness and precision with which he marked resemblances and discriminated differences, the sagacity with which he devised experiments and anticipated their results, and the skill with which he executed the analysis of fragments of new substances, often so minute as to be scarcely perceptible by ordinary eyes. He was remarkable, too, for the caution with which he advanced from facts to general conclusions; a caution which, if it sometimes prevented him from reaching at once the most sublime truths, yet rendered every step of his ascent a secure station, from which it was easy to rise to higher and more enlarged inductions."--_Weld's History of the Royal Society, with Memoirs of the Presidents._ London, 1848.--_Sketches of the Royal Society, &c., by Sir John Barrow, Bart., F.R.S._ London, 1849.

THOMAS YOUNG, M.D., F.R.S., &c.

MEMBER OF THE INSTITUTE OF FRANCE.

Born June 13, 1773. Died May 10, 1829.

Dr. Thomas Young, celebrated for his universal attainments, was born at Milverton, in Somersetshire. He was the eldest of ten children of Thomas and Sarah Young; his mother was a niece of Dr. Richard Brocklesby, a physician of considerable eminence in London. Both of his parents were members of the Society of Friends, and to the tenets of that sect, which recognizes the immediate influence of a Supreme Intelligence as a guide in the ordinary conduct of life, Dr. Young was accustomed in after years to attribute, in no slight degree, the formation of those determined habits of perseverance which gave him the power of effecting any object upon which he was engaged, and by which he was enabled to work out his own education almost from infancy, and with little comparative assistance from others. At the age of two years Young could read with considerable fluency, and before he was four years old had read the Bible through twice, and also Watts' hymns. He was likewise from his earliest years in the habit of committing to memory pieces of poetry, in proof of which there exists a memorandum, written by Young's grandfather, on the margin of a copy of Goldsmith's 'Deserted Village,' to the effect that his grandson Thomas had repeated to him the whole poem, with the exception of a word or two, before he was five years old. In 1780 he was placed at a boarding-school at Stapleton, near Bristol, and here the deficiency of the instructor appears to have advanced the studies of the pupil, as Young now became his own teacher, and used to study by himself the last pages of the book taught almost before he had reached the middle under the eye of the master.

In the year 1782 he became an inmate of the school kept by Mr. Thompson, at Crompton, in Dorsetshire, remaining there nearly four years, during which period he rapidly acquired knowledge upon various subjects. Having commenced the study of botany, he was led to attempt the construction of a microscope, with the assistance of an usher in the school of the name of Benjamin Martin, in order to examine the plants he was in the habit of gathering. In his endeavours to make the microscope Young found it necessary to procure a lathe, and for a time everything gave way to a passion for turning. This was, however, at length succeeded by a desire to become acquainted with the nature of fluxions, and after reading through and mastering a treatise upon this subject, he turned his attention to the study of Hebrew and other Oriental languages. Ultimately at the age of fourteen Thomas Young was more or less versed in Greek, Latin, French, Italian, Hebrew, Persic, and Arabic, and in forming the characters of these languages had already acquired a considerable portion of that beauty and accuracy of penmanship which was afterwards so remarkable in his copies of Greek compositions, as well as those subjects connected with the literature of ancient Egypt. A story is related of him, that when requested a few years later, by a friend of Dr. Brocklesby, who presumed somewhat upon Young's youthful appearance, to exhibit a specimen of his penmanship, he replied by writing a sentence in his best style in fourteen different languages.

In 1787 Young was engaged, in conjunction with Mr. Hodgkin, as private tutor to Hudson Gurney, grandson of Mr. David Barclay, of Youngsbury, near Ware, in Hertfordshire, and he remained thus occupied during the space of five years, extending his knowledge as far as possible. The number of books he read through at that time was comparatively small, but whatever book he began to read, he read completely and deliberately through, and it was perhaps this determination always to master what he might happen to be engaged on before attempting anything else, which enabled Dr. Young to attain so great knowledge on such various subjects. He himself had little faith in any peculiar aptitude being implanted by nature for any given pursuits. His favourite maxim was, that whatever one man had done another might do, and that the original difference between human intellects was much less than it was supposed to be; in this respect he resembled his great predecessor Newton, and his cotemporary Dalton, both of whom had unbounded confidence in the powers of patient thought.

In the autumn of 1792 Thomas Young removed to London, in order to study medicine, which profession he had determined to adopt, being greatly influenced in his choice by the wishes of his uncle Dr. Brocklesby. This gentleman had kindly undertaken the charge of his education, and Young was by him introduced to the members of the most distinguished literary circles in the metropolis, including Burke, Drs. Lawrence and Vincent, Sir Joshua Reynolds, Sir George Baker, and others. In the autumn of 1793 he became a pupil at St. Bartholomew's Hospital, and in October 1794 proceeded to Edinburgh, still further to prosecute his medical studies. While residing at Edinburgh Dr. Young mixed largely in society, began the study of music, took lessons on the flute, and also private lessons in dancing, and frequently attended performances at the theatre. From this period he gave up the external characteristics of the Quakers, and ultimately ceased to belong to their body, although he practised to the end of his life the general simplicity of their moral conduct.

During the year 1795 he commenced a tour on the Continent, staying at the University of Göttingen during nine months, in order to prosecute his studies and take a doctor's degree. In February, 1797, he came back to England, and was almost immediately after his return admitted a Fellow-Commoner of Emmanuel College, Cambridge; the Master of the College, Dr. Farmer, saying as he introduced Young to the fellows, "I have brought you a pupil qualified to read lectures to his tutors."

In December 1797 Young's uncle, Dr. Brocklesby, died, bequeathing to his nephew the sum of 10,000_l._, besides his house, furniture, and a choice collection of pictures. Dr. Young was now entirely at liberty to form his own scheme of life, and he determined to commence practice as a physician, for which purpose, after having completed his terms of residence at Cambridge, he took a house in Welbeck Street (No. 48), which he continued to occupy for five-and-twenty years. His practice as a physician, although respectable, was never large. He wanted that confidence or assurance which is so necessary to the successful exercise of the profession. He was perhaps too deeply informed, and therefore too sensible of the difficulty of arriving at true knowledge in the science of medicine ever to form a hasty judgment; while his great love of, and adherence to truth, made him often hesitate where others would have felt no difficulty in expressing an opinion. It was perhaps a happy circumstance for the fame of Dr. Young that this should be the case, as he was thereby enabled to devote a considerable portion of his time to those literary and scientific studies in which so few could compete with him. In 1799 he published his memoir entitled 'Outlines and Experiments respecting Sound and Light,' which was read before the Royal Society and printed in their 'Transactions.' Other papers, 'On the Theory of Light and Colours,' followed, which the council of the Royal Society selected for the Bakerian lectures. In the year 1801 Dr. Young accepted the office of Professor of Natural Philosophy at the Royal Institution, which had been established the year previously. The conducting of the journal of the Institution was also entrusted to his care, in conjunction with his colleague Sir Humphry Davy, at that time Professor of Chemistry. Dr. Young remained at the Royal Institution two years, during which period he gave a course of lectures on 'Natural and Experimental Philosophy,' a syllabus of which he published in 1802, announcing for the first time his great discovery of the general law of the interference of the undulations of light. His lectures were not, however, popular; they embodied too much knowledge to be intelligible to any considerable portion of his hearers; and the matter was so abundant and the style so condensed, that students tolerably versed in science might have found it extremely difficult to follow him in his masterly discussions.

Dr. Young had been elected a Fellow of the Royal Society as early as the year 1794, when he had just completed his twenty-first year; he was now appointed (1802) Foreign Secretary to the same Society, an office which he held during the remainder of his life, and for which he was well qualified by his knowledge of the principal languages of Europe.

In 1804 he married Eliza, the daughter of James Primrose Maxwell, of Cavendish Square, and this union is said to have been attended with uninterrupted happiness; his wife who survived him left no children.

In 1807 appeared his most elaborate and valuable work, 'A Course of Lectures on Natural Philosophy and the Mechanical Arts,' being the embodiment of the sixty lectures delivered while at the Royal Institution, together with the labour of three more years occupied in further arranging and improving them. This work comprises a complete system of natural and mechanical philosophy, drawn from original sources, and is distinguished not only by the extent of its learning and the accuracy of its statements, but by the beauty and originality of the theoretical principles. It also contains a disquisition upon the doctrine of interference in the undulatory theory of light mentioned before, the general law of which he thus enunciates: "When two undulations from different origins coincide, either perfectly or very nearly in direction, their joint effect is a combination of the motions belonging to each."[49] Sir John Herschel, speaking of this discovery, says that it alone "would have sufficed to have placed its author in the highest rank of scientific immortality, even were his other almost innumerable claims to such a distinction disregarded." Amongst other laborious and difficult matters of investigation, Dr. Young made the first and most important steps in reading the Egyptian Hieroglyphics, in which he preceded Champollion; and he afterwards, in 1823, published a work on this subject, under the title of 'An Account of some recent Discoveries in Hieroglyphical Literature and Egyptian Antiquities; including the author's original Alphabet as extended by Mr. Champollion; with a Translation of five unpublished Greek and Egyptian Manuscripts.' In the year 1808 Dr. Young was admitted a fellow of the College of Physicians, and in 1810 was elected physician to St. George's Hospital, a situation which he retained for the remainder of his life. In 1813 he published 'An Introduction to Medical Literature, including a system of practical Nosology intended as a guide to Students and as an Assistant to Practitioners.' In 1816 Dr. Young was appointed Secretary to the Commission empowered to ascertain the length of the second's pendulum, and thereby establish an uniform system of weights and measures. Two years subsequent to this he became secretary to the Board of Longitude, and on the dissolution of that body, became sole conductor of the 'Nautical Almanac.' Dr. Young at various times contributed eighteen articles to the 'Quarterly Review,' of which nine were on scientific subjects--the rest on medicine, languages, and criticism. Between 1816 and 1823 he wrote sixty-three articles for the 'Supplement to the Encyclopædia Britannica,' Sixth Edition, of which forty-six were biographical. In the year 1821 he made a short tour in Italy with his wife, and, in August 1827, was elected one of the eight Foreign associates of the Academy of Sciences at Paris, in the place of Volta, who died in 1826; the other competitors for this honour being the astronomers Bessel and Olbers, Brown the botanist, Blumenback, Leopold, Von Buch, Dalton, and Plana the mathematician.

Dr. Young's course of life, considered apart from the variety of his occupations, was remarkably uniform. He resided in London from November to June, and at Worthing from July to the end of October, continuing this regular change of residence for fourteen successive years. In the year 1826 he removed from his house in Welbeck Street, where he had resided for a quarter of a century, to another in Park Square, which had been built under his own directions, and fitted up with great elegance and taste. He continued to live here for the remainder of his life. During the month of February, 1829, he began to suffer from what he considered repeated attacks of asthma. His health gradually got worse, but though thus under the pressure of severe illness, nothing could be more striking than the entire calmness and composure of his mind, or could surpass the kindness of his affections to all around him. In the very last stage of his complaint, in an interview with Mr. Gurney, his perfect self-possession was displayed in the most remarkable manner. After some information concerning his affairs, and some instructions concerning the hieroglyphical papers in his hands, he said, that perfectly aware of his situation, he had taken the sacrament of the Church on the day preceding; that whether he should ever partially recover, or whether he were rapidly taken off, he could patiently and contentedly await the issue. His illness continued, with some slight variations, until the morning of the 10th of May, when he expired without a struggle, having hardly completed his fifty-sixth year. The disease proved to be an ossification of the aörta, the large arterial trunk proceeding from the left ventricle of the heart. It must have been in progress for many years, and every appearance indicated an advance of age, not brought on probably by the natural course of time, nor even by constitutional formation, but by unwearied and incessant labour of mind from the earliest days of infancy. His remains were deposited in the vault of his wife's family, in the church of Farnborough, in Kent.--_Life of Thomas Young, M.D., &c., by Dr. George Peacock, Dean of Ely._ London, 1855.--_Memoir by Dr. D. Irving_, _Encyclopædia Britannica_, Eighth Edition.--_English Cyclopædia._ London, 1858.

APPENDIX.

JOSEPH BLACK, M.D.

PROFESSOR OF THE UNIVERSITIES OF EDINBURGH AND GLASGOW.

Born 1728.[50] Died November 26, 1799.

Dr. Joseph Black was born at Bourdeaux, where his father, a native of Belfast but of Scotch descent, was settled as a wine merchant; and being a man of engaging disposition and extensive information was much esteemed by his friends, among whom he reckoned Montesquieu, at that time one of the presidents of the court of justice in the province where Mr. Black resided. At the age of twelve Joseph Black was sent to a school at Belfast, where he remained for some years. In 1746 he was removed to the College at Glasgow and ever afterwards lived in Scotland, which was, properly speaking, his native country. While at the College of Glasgow he studied under the celebrated Dr. Cullen, then professor of anatomy and lecturer on chemistry, and in the year 1751 removed to Edinburgh to complete the course of his medical studies. In the following year Black made his first great discovery of the cause of the causticity of lime, a property till then supposed to be due to the absorption by the lime of some igneous agency. He placed this question on a scientific basis by ascertaining the chemical difference between quick-lime and other forms of the carbonate, and first announced his discovery in a Latin Thesis upon the occasion of his taking his degree of Doctor of Medicine in 1754. It was not, however, given in its fullest details until the year afterwards, when he published his celebrated work entitled, 'Experiments on Magnesia, Quick-lime, and other alkaline substances;' a work which Lord Brougham describes as being incontestably the most beautiful example of strict inductive investigation since the 'Optics' of Sir Isaac Newton. In 1754, as has been mentioned, Black took his medical degree at Edinburgh; in 1756 he was appointed to succeed Dr. Cullen as professor of anatomy and lecturer on chemistry in the University of Glasgow. Soon after, however, he exchanged this for the professorship of medicine at the same university, as being more congenial to his tastes. Dr. Black continued at the University of Glasgow for the next ten years, and it was during this period, between the years 1759 and 1763, that he brought to maturity his speculations concerning _heat_, which had occupied his attention from the very first commencement of his philosophical investigations. His two great discoveries were the doctrines of 'Latent Heat,' and 'Specific Heat.' The theory of 'Latent' Heat, which mainly urged Watt to the adoption of improved arrangements in the steam-engine, may be briefly described as the absorption of heat by bodies passing from the solid to the fluid state, and from the fluid to the aëriform, the heat having no effect on surrounding bodies (being, therefore, insensible to the hand or thermometer), and only by its absorption maintaining the body in the state which it has assumed, and which it retains until the absorbed heat is given out and has become again sensible, when the state of the body is changed back again from fluid to solid, from aëriform to fluid.

The doctrine of 'Specific Heat,' or as it was called by Dr. Black the _capacity_ of bodies for heat, is summed up in the facts, that different bodies contain different quantities of heat in the same bulk or weight; and different quantities of heat are required to raise different bodies to the same sensible temperature. Thus it was found that a pound of gold being heated to 150° and added to a pound of water at 50° the temperature of both became not 100°, the mean between the two but 55°, the gold losing 95° and the water gaining 5°, because the capacity of water for heat is 19 times that of gold. So twice as much heat is required to raise water to any given point of sensible heat as to raise mercury, the volumes of the two fluids compared being equal. The true doctrine of combustion, calcination of metals, and respiration of animals, which Lavoisier deduced from the experiments of Priestly and Scheele upon oxygen gas, and of Cavendish on hydrogen gas, was founded mainly upon the doctrines of latent and specific heat; and it was thus the singular felicity of Black to have furnished both the pillars upon which modern chemistry reposes.

In 1766 Black succeeded Dr. Cullen in the professorship of chemistry at the University of Edinburgh, and in the new scene on which he entered his talents became more conspicuously and more extensively useful. Dr. Robison thus characterises him as a lecturer--"He became one of the principal ornaments of the university, his lectures were attended by an audience which continued increasing from year to year; his personal appearance and manners were those of a gentleman, and peculiarly pleasing. His voice in lecturing was low but fine, and his articulation so distinct that he was perfectly well heard by an audience consisting of several hundreds. His discourse was so plain and perspicuous, his illustration by experiment so apposite, that his sentiments on any subject never could be mistaken even by the most illiterate." Dr. Black continued to lecture at the University of Edinburgh for thirty years; he then retired and died three years afterwards, in 1799. His health, never robust, was precarious at all times from a weakness in the bronchia and chest, but he prolonged life by a system of strictest abstinence, frequently subsisting for days together on watergruel and diluted milk. He was never married. He lived in a select circle of friends, the most illustrious men of the times in science and in letters; Watt, Hutton, Hume, Robertson, Smith; and afterwards with the succeeding generation of Scottish worthies, Robison, Playfair, and Stewart. He was extremely averse to publication, contemning the impatience with which so many men of science hurry to the press, often while their speculations are crude and their inquiries not finished. He never published any work himself with the exception of his 'Experiments on Magnesia, &c.,' and two papers, one in the 'London Philosophical Transactions' for 1775 on the Freezing of boiled Water; the other in the second vol. of the 'Edinburgh Transactions,' on the Iceland Hot Springs.