|
 THOMSON,
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? |
