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Thomas Thomson

Thomas ThomsonTHOMSON, THOMAS, M.D., F.R.S., Regius Professor of Chemistry in the University of Glasgow.—This distinguished chemist was the seventh child and youngest son of John Thomson and Elizabeth Ewan, and was born at Crieff, on the 12th April, 1773. He was first educated at the parish school of Crieff, and was sent, in 1786, in his thirteenth year, for two years, by the advice of his brother, and of his uncle, the Rev. John Ewan, minister of the parish of Whittingham, in East Lothian, a man of some independent means, to the borough school of Stirling, at that time presided over by Dr. Doig, the distinguished author of the "Letters on the Savage State." Here he acquired a thorough classical education, the benefits of which have been so signally manifested in his numerous improvements of chemical nomenclature now generally adopted in the science. In consequence of having written a Latin Horatian poem of considerable merit, his uncle was recommended, by Principal M’Cormack of St. Andrews, to advise that he should try for a bursary at that university, which was open to public competition. He accordingly went, in 1788, to that school of learning, and, having stood an examination, carried the scholarship, which entitled him to board and lodging at the university for three years. In 1791 he came to Edinburgh, and became tutor in the family of Mr. Kerr of Blackshields, one of his pupils being afterwards well known in connection with the bank of Leith. In session 1794-5 he began the study of medicine, and in 1795 resided in Edinburgh with his elder brother, afterwards the Rev. James Thomson, D.D., and still (1855) minister of the parish of Eccles, author of many articles in the "Encyclopedia," and of works on the Gospel by St. Luke and Acts, and who succeeded the late Bishop Walker as colleague to Dr. (afterwards Bishop) Gleig, in the editorship of the "Encyclopedia Britannica." In the session of 1795-6 Dr. Thomson attended the lectures of the celebrated Dr. Black, of whom he always spoke in terms of the utmost veneration, and of gratitude for those invaluable instructions which first awoke the latent taste for the science of which he was destined to become so bright an ornament. In this session he wrote the article "Sea" for the "Encyclopaedia." In November, 1796, he succeeded his brother in the editorship of the third edition of the "Encyclopaedia," and remained connected with it till 1800. It was during this period that he drew up the first outline of his "System of Chemistry," which appeared in the Supplement to the "Encyclopedia," under the articles Chemistry, Mineralogy, Vegetable Substances, Animal Substances, and Dyeing Substances. These all appeared before the 10th December, 1800, when the preface was published, in which it is stated, by Dr. Gleig: of the author "of these beautiful articles, a man of like principles with Dr. Robison, it is needless to say anything, since the public seems to be fully satisfied that they prove their author eminently qualified to teach the science of chemistry." During the winter session of 1800-1, he gave his first chemical course with fifty-two pupils. Hence he appears to have been before the public as a lecturer for the long period of fifty-two years, and, as he used latterly to say, he believed he had lived to be the oldest teacher in Europe.

It was in the article Mineralogy, written about 1798, that he first introduced the use of symbols into chemical science, universally acknowledged to be one of the most valuable improvements in modern chemistry. In this article he arranges minerals into genera, according to their composition. Thus his first genus is A, or alumina, under which are two species, topaz and corundum, in accordance with the analyses of the day. The second genus is A M C, comprising spinell, which, according to Vauquelin, contained alumina, magnesia, and chrome iron ore. The fourth genus is S, including the varieties of silica or quartz. The eighth genus is S A G, or silica, alumina, and glucina, including the emerald or beryl; and thus he proceeds throughout. In the editions of his "System," the first of which (a development of the original article in the Encyclopaedia) was published in 1802, he continued the same arrangement and symbols, and was thus not only the originator of symbolic nomenclature in modern chemistry, but was the first chemist to bring mineralogy systematically within the domain of that science. In the third edition of his "System," published in 1807, in illustrating the atomic theory of Dalton, and in his article on oxalic acid, in the Philosophical Transactions for 1808, he freely uses symbols. Berzelius, who appeared some years later on the chemical stage, being Dr. Thomson’s junior by five years, published a work in 1814, in Swedish, in which he adopted the system of symbols used by Dr. Thomson, with some modifications (the introduction of Latin initials in certain cases), but he strictly "followed the rules for this purpose given by Thomson in his ‘System of Chemistry," (öch skall dervid fölga en enledning som Thomson gifvit i sin kemiska handbok). The work in which this passage occurs, entitled "Försök att genom anvandandet af den electrokemiska theorien, &c., grundlagga for mineralogier," af J. Jacob Berzelius, Stockholm, 1814, p. 18, was sent by Berzelius to Dr. Thomson, in the same year, with a request, in a letter which is still extant, that he would endeavour to procure a translator for it. Dr. Thomson applied to Dr. Marcet and others without success; but at last prevailed on his learned friend, John Black, Esq., who so ably conducted the "Morning Chronicle" for many years, to undertake the task. Dr. Thomson graduated in 1799. He continued to lecture in Edinburgh till 1811, and during that time opened a laboratory for pupils, the first of the kind, it is believed, in Great Britain. Among those who worked in his laboratory was Dr. Henry of Manchester, a chemist, for whom he had always the greatest regard, who had visited Edinburgh for the purpose of graduation, and who there made many of his experiments on the analysis of the constituents of coal-gas. During this period likewise, Dr. Thomson made his important investigations for Government on the malt and distillation questions, which laid the basis of the Scottish legislation on excise, and rendered him in after-life the arbitrator in many important revenue cases. He likewise invented his saccharometer, which is still used by the Scottish excise under the title of Allan’s saccharometer. In 1807 he first introduced to the notice of the world, in the third edition of his "System," Dalton’s views of the atomic theory, which had been privately communicated to him in 1804. He did not confine his remarks to mere details, but made many important new deductions, and by his clear, perspicuous, and transparent style, rendered the new theory soon universally known and appreciated. Had Richter possessed such a friend as Thomson, the atomic theory of Dalton would have long been previously fully discovered and attributed to Richter. In his papers on this theory, which occupied much of his thoughts, from the mathematical precision which it promised to impart to the science, we find numerous suggestions cautiously offered, which have often been subsequently examined and confirmed, or developed in another direction. Thus, in August, 1813, he states that, according to the atomic numbers then determined, "an atom of phosphorus is ten times as heavy as an atom of hydrogen. None of the other atoms appear to be multiples of 132 (the atom of hydrogen at that time adopted by chemists), so that, if we pitch upon hydrogen for our unit, the weight of all the atoms will be fractional quantities, except that of phosphorus alone." It was undoubtedly this observation which caused Dr. Prout to make new inquiries, and to announce, in Nov. 1815, the view that the relation of phosphorus as a multiple of hydrogen, as detected by Thomson, may be general, connecting all other atomic weights with that unit—a view now generally adopted, and considered as a nearly demonstrated law.

The existence of such mathematical relations Dr. Thomson was continually in the habit of testing at the conclusion of his own researches, or in examining the experiments of others. Any peculiarity of character in a substance hitherto known, or in a newly-discovered body, he never failed to point out in his "System;" and innumerable instances have occurred, and might be mentioned did our space admit, where lucrative patents have resulted from a simple statement or foot-note, often original on the part of the author. A fact of this kind in the "Animal Chemistry" led Mr. Robert Pattison to his ingenious patent invention of lactarin, a preparation of casein from milk, for fixing ultramarine on cotton cloth; and Dr. Thomson’s systematic plan of describing all the characters of bodies in detail, led Henry Rose of Berlin to the discovery of niobium and pelopium, two new metals. From the fragments of four imperfect crystals of certain tantalites, as the mineral dealers who sold them to him termed them, he was enabled to make some analyses, and to take a series of specific gravities, which he published in a paper "On the Minerals containing Columbium," in his nephew, Dr. H. D. Thomson’s "Records of General Science," vol. iv., p. 407, in 1836. He found that these minerals possessed an analogous constitution, but their specific gravity differs. He termed them torreylite, columbite, tantalite, and ferrotantalite. In making his experiments he expended all the material he possessed, and he had passed the great climacteric. Professor Rose, struck with the facts, examined the minerals upon a greater scale, and, after immense labour, showed that not only columbic or tantalic acid was present in these minerals, but likewise two new acids, niobic and pelopic acids. Instances of this kind of contribution made by Dr. Thomson to chemistry might be indefinitely particularized. About 1802 he invented the oxy-hydrogen blowpipe, in which he introduced the oxygen and hydrogen into one vessel; but the whole apparatus having blown up and nearly proved fatal to him, he placed the gases in separate gas-holders. At that time he made many experiments on its powers of fusion, but as Dr. Hare had invented an apparatus at the same time, and published his experiments, Dr. Thomson did no more than exhibit the apparatus in his lectures. In August, 1804, in a paper on lead, he first published his new nomenclature of the oxides and acids, in which Latin and Greek numerals were made to denote the number of atoms of oxygen in an oxide. He thus introduces this important invention, which has been almost universally adopted in the science:—"As colour is a very ambiguous criterion for distinguishing metallic oxides, I have been accustomed for some time to denote the oxide with a minimum of oxygen, by prefixing the Greek ordinal number to the term oxide. Thus, protoxide of lead is lead united to a minimum of oxygen; the oxide, with a maximum of oxygen, I call peroxide. Thus, brown oxide of lead is the peroxide of lead. I denominate the intermediate degrees of oxidizement by prefixing the Greek ordinals, 2nd, 3rd, 4th, &c. Thus, deutoxide is the second oxide of lead, tritoxide of cobalt the third oxide of cobalt, and so on." This paper being translated and published in France, the nomenclature was speedily introduced into that country. But the improvements which he afterwards adopted by denoting the exact number of atoms of oxygen present, by the Latin, and those of the base by the Greek numerals, and used in Great Britain, never superseded, in that country, the original suggestion in the above note.

All these inventions were merely particular parts of a systematic arrangement adopted in his "System of Chemistry"—a work which, if carefully examined with a philosophic eye, will be found to have produced beneficial results to chemical science, similar to those which the systems of Ray, Linnaeus, and Jussieu effected for botany. In his second edition, published in 1804 (the first large edition having been sold in less than ten months), he divided the consideration of chemical bodies into—Book I. Simple Substances: 1. Confinable bodies, including oxygen, simple combustibles, simple incombustibles, metals; 2. Unconfinable bodies, comprising heat and light. Book II. Compound Bodies: 1. Primary compounds; 2. Secondary compounds, &c. It is most interesting to observe how his plan was developed with the progress of the science in the different editions. It is sufficient to say that it was generally considered as a masterly arrangement, and used to be quoted by the Professor of Logic in Edinburgh, as an admirable example of the analytic and synthetic methods. Previous to the publication of his "System," British chemists were contented with translations from the French; and hence it was believed on the Continent that "Britain possessed scarcely a scientific chemist." That all his contemporaries viewed his plan as highly philosophic cannot be affirmed. There are some men who, having no mental powers of arrangement in themselves, discover in a systematic treatise only a compilation possessing the generic characters of matter; while those who can pry below the surface, on the other hand, know that the art of arranging is one of the most difficult tasks of the philosopher; that it requires a comprehensiveness of mind, a clearness of judgment, and a patience of labour, which fall to the lot of a small number of the human race. When we recollect that many of these remarkable views began to be devised by the self-taught chemist, in a narrow close in the High Street of Edinburgh, the author being in the receipt of a salary of £50 a-year, from which he sent £15 to his aged parents; and when we contrast such a picture with the costly education and refined apparatus of the modern laboratory, it is impossible to avoid the inference, that in Dr. Thomson Britain possessed a genius of no common order.

One immediate result of the publication of his "System" was the appropriation of their due merit to respective discoverers, and especially to British chemists, who had been overlooked in the Continental treatises. It was the subject of our memoir who thus first imparted to us the true history of chemistry, and in doing so often gave offence to disappointed individuals; but the honesty of his nature and his unswerving love of truth never allowed him for a moment to sacrifice, even in his own case, the fact to the fallacy.

During the first years of this century, he discovered many new compounds and minerals, as chloride of sulphur, allanite, sodalite, &c.; but to give a list of the numerous salts which he first formed and described during his onward career would be difficult, as he scarcely ever treated of them in separate papers, but introduced them into the body of his "System," without any claim to their discovery. His exact mind was more directed towards accurate knowledge and principles, than to novelties merely for their own sake, although there is probably no chemist who has added so many new bodies to the science. Hence, many of his discoveries have been attributed to others, or re-discovered over and over again, as was the case with many of his chromium compounds—viz., chlorochromic acid, the two potash oxalates of chromium, bichromate of silver, potash chromate of magnesia, chromate of chromium, hyposulphurous acid (1817), and hydrosulphurous acid (1818), S5 0, &c., all of which were examined by him above a quarter of a century ago.

In 1810, Dr. Thomson published his "Elements of Chemistry," in a single volume, his object being to furnish an accurate outline of the actual state of the science. In 1812 he produced his "History of the Royal Society," a most important work, as showing the influence which that society produced on the progress of science. in August, 1812, he made a tour in Sweden, and published his observations on that country in the following year. It is still a valuable work, and contains a very complete view of the state of science and society in Sweden. In 1813 he went to London, and started the "Annals of Philosophy," a periodical which he continued to conduct till 1822, when the numerous calls upon his time in the discharge of the duties of his chair at Glasgow, compelled him to resign the editorship in favour of Mr. Richard Phillips, one of his oldest friends, who pre-deceased him by one year The journal was, in 1827, purchased by Mr Richard Taylor, and was merged in the "Philosophical Magazine." In 1817, he was appointed lecturer on chemistry in the university of Glasgow; and in 1818, at the instance of the late Duke of Montrose, Chancellor of that institution, the appointment was made a professorship with a small salary under the patronage of the Crown. As soon after his appointment as he was enabled to obtain a laboratory, he commenced his researches into the atomic constitution of chemical bodies, and produced an amount of work unparalleled in the whole range of the science, in 1825, by the publication of his "Attempt to Establish the First Principles of Chemistiy by Experiment, in 2 vols. It contained "the result of many thousand experiments, conducted with as much care and precision as it was in his power to employ. In this work he gives the specific gravities of all the important gases, ascertained by careful experiment. The data thus ascertained were often disputed and attacked in strong but unphilosophical terms, as they tended to supersede previous experimental deductions; but the excellent subsequent determinations of specific gravities by Dumas, which were made at the request of Dr. Thomson, after that distinguished chemist had visited him at Glasgow in 1840, fulls substantiated the greater accuracy of Dr Thomson’s numbers over those which preceded him, and in most cases furnished an identity of result. The atomic numbers given in his "First Principles" as the result of his labours, were the means of a vast number of experiments made by himself and pupils, the data of which still exist in his series of note books. They all tended to the result that the atomic weights of bodies are multiples by a whole number of the atomic weight of hydrogen—a canon confirmed to a great extent by the recent experiments of French and German chemists, and which he himself was the first to point out in the case of phosphorus. That the subject of our memoir was frequently in error in his experiments is not attempted to be denied, for, as the great Liebig has said, it is only the sluggard in chemistry who commits no faults; but all his atomic weights of important bodies have been confirmed. After the publication of this work, he devoted himself to the examination of the inorganic kingdom of nature, purchasing and collecting every species of mineral obtainable, until his museum, now (1855) at St. Thomas’s Hospital, London, which he has left behind him, became not only one of the noblest mineral collections in the kingdom, but a substantial monument of his taste and of his devotion to science. The results of his investigation of minerals were published in 1836, in his "Outlines of Mineralogy and Geology," in 2 vols., and contained an account of about fifty new minerals which he had discovered in a period of little more than ten years. In 1830-1, Dr. Thomson published his "History of Chemistry," a masterpiece of learning and research. During these feats of philosophic labour, the eyes of the community were attracted to Glasgow as the source from which the streams of chemistry flowed, the class of chemistry and the laboratory being flocked to as to fountains of inspiration.

It would be a great omission not to mention that it was Dr. Thomson who introduced a system of giving annual reports on the progress of science in his "Annals of Philosophy;" the first of these was published in 1813, and the last in 1819. These reports were characterized by his usual perspicuity and love of suum cuique which distinguished his conduct through life, and were composed with a mildness of criticism far more conducive to the dignity of the science than those which, three years after his reports had ceased, were begun by the distinguished Swedish chemist, Berzelius. In 1835, when Dr. R. D. Thomson started his journal, "The Records of General Science," his uncle contributed to almost every number, and encouraged him by his sympathy in his attempts to advance science.

Dr. Thomson continued to lecture till the year 1841, discharging all the duties of his chair without assistance; but being then in his 69th year, and feeling his bodily powers becoming more faint, he associated with him at that period his nephew and son-in-law, Dr. R D. Thomson, who was then resident in London. He continued, however, to deliver the inorganic course only till 1846, when the dangerous illness of his second son, from disease contracted in India, hurried him for the winter to Nice, when his nephew was appointed by the university to discharge the duties of the chair, which he continued to perform till Dr. Thomson’s death. Of the hardship of being obliged in his old age thus to toil in harness, and to have no retiring allowance, he never murmured or complained. But there were not wanting suggestions, that one who had raised himself to eminence from comparative obscurity, and who had benefited his country in no common measure, might have been relieved in some degree by the guardians of the state, without popular disaffection, from fatigues which even a green old age cannot long sustain. Dr. Thomson continued to attend the examinations for degrees for some years after retiring from the duties of the chair; but in consequence of the increasing defect in his hearing, he ultimately gave up this duty, and confined his public labours to attendance at the fortnightly meetings of the winter session of the Philosophical Society of Glasgow, of which he was president from the year 1834. His last appearance there was on the 6th November, at the first meeting of the session 1850-51, when he read a biographical account of his old and affectionate friend, Dr. Wollaston, to whom he was ever most strongly attached. During the early part of 1852 his frame became visibly weaker, and, latterly, having removed to the country, where it was hoped the freshness of the summer season might brace his languishing powers, his appetite failed; but no pain appeared to mar the tranquil exit of the philosophic spirit. To inquiries after his health—"I am quite well, but weak," the good old man replied, within a few hours of his last summons. On the morning of the 2d of July he breathed his last in the bosom of his affectionate family, on the lovely shores of the Holy Loch. Dr. Thomson married, in 1816, Miss Agnes Colquhoun, daughter of Mr. Colquhoun, distiller, near Stirling, with whom he enjoyed most complete and uninterrupted happiness. He was left a widower in 1834. He left a son, Dr. Thomas Thomson, of the Bengal army, the author of "Travels in Tibet," the result of several years’ researches into the botany and physical structure of the Himalaya Mountains, and now (1855) superintendent of the Botanic Gardens at Calcutta; and a daughter, married to her cousin, Dr. R. D. Thomson, Professor of Chemistry at St. Thomas’s Hospital, London. On strangers, Dr. Thomson occasionally made an unfavourable impression; but by all who knew him intimately, he was universally recognized as the most friendly and benevolent of men. Dr. Thomson was originally destined for the Church of Scotland, and continued to the last a faithful adherent. He was wont to attribute his sound and intellectual views of the Christian faith to the care of his mother—a woman of great beauty and sense; and it was perhaps from his affection for her that his favourite axiom originated—that the talents are derived from the maternal parent. Who shall prescribe exact limits to the benefits conferred on her country and her race by this humble, but pious Christian woman—who taught in early life religion to her elder son, the author of the article Scripture, in the "Encyclopaedia Britannica," which, in the third and many subsequent editions of that work, has been read and distributed over the globe for nearly half a century, to a greater extent than perhaps any other religious treatise—and who gave the earliest impressions of his relations to his Maker to the great chemical philosopher?

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