Jean-Baptiste-Andre Dumas was born at Alais, in the south of France,
July 14, 1800. His father belonged to an ancient family, was a man of
culture, and held the position as clerk to the municipality of Alais.
The son was educated at the college of his native place, and appears to
have been destined by his parents for the naval service. But the anarchy
and bloodshed which attended the downfall of the First Empire produced
such an aversion to a military life that his parents abandoned their
plan, and apprenticed him to an apothecary of the town. He remained in
this situation, however, but a short time; for, owing to the same sad
causes, he had formed an earnest desire to leave his home, and, his
parents yielding to his wish, he traveled on foot to Geneva in 1816,
where he had relatives who gave him a friendly welcome, and where he
found employment in the pharmacy of Le Royer.
[K] Reprinted from the Proceedings of the American Academy of
Arts and Sciences, vol. xix, 1883-'84.
At that time Geneva was the center of much scientific activity, and
young Dumas, while discharging his duties in the pharmacy, had the
opportunity of attending lectures on botany by M. de Candolle, on
physics by M. Pictet, and on chemistry by M. Gaspard de la Rive; and
from these lectures he acquired an earnest zeal for scientific
investigation. The laboratory of the pharmacy gave him the necessary
opportunities for experimenting, and an observation which he made of the
definite proportions of water contained in various commercial salts,
although yielding no new results, gained for him the attention and
friendship of De la Rive. Soon after we find the young philosopher
attempting to deduce the volumes of the atoms in solid and liquid bodies
by carefully determining their specific gravities, and thus anticipating
a method which thirty years later was more fully developed by Hermann
Kopp.
About this time young Dumas had the good fortune to render an important
service to one of the most distinguished physicians of Geneva, whose
name is associated with the beneficial uses of iodine in cases of
goitre. It had occurred to Dr. Coindet that burned sponge, then
generally used as a remedy for that disease, might owe its efficacy to
the presence of a small amount of iodine; and on referring the question
to Dumas, the young chemist not only proved the presence of iodine in
the sponge, but also indicated the best method of administering what
proved to be almost a specific remedy. It was in connection with this
investigation that Dumas's name first appears in public. The discovery
produced a great sensation, and for many years the manufacture of iodine
preparations brought both wealth and reputation to the pharmacy of Le
Royer.
Soon after, Dumas formed an intimacy with Dr. J. L. Prevost, then
recently returned from pursuing his studies in Edinburgh and Dublin, and
was induced to undertake a series of physiological investigations, which
for a time withdrew him from his strictly chemical studies. Several
valuable papers on physiological subjects were published by Prevost and
Dumas, which attracted the notice of Alexander von Humboldt, who on
visiting Geneva, in 1822, sought out Dumas and awakened in him a desire
to seek a wider field of activity than his present position opened to
him. In consequence he removed to Paris in 1823, where the reputation he
had so deservedly earned at Geneva won for him a cordial reception at
what was then the chief center of scientific study in Europe. La Place,
Berthollet, Vauquelin, Gay-Lussac, Thenard, Alexandre Brongniart,
Cuvier, Geoffroy St. Hilaire, Arago, Ampere, and Poisson, all
manifested their interest in the young investigator. Dumas was soon
appointed Repetiteur de Chimie at the Ecole Polytechnique, and also
Lecturer at the Athenaeum, an institution founded and maintained by
public subscription, for the purpose of exciting popular interest in
literature and science; and from this beginning his advancement to the
highest position which a man of science can occupy in France was
extremely rapid.
In 1826 he married Mdlle. Herminie Brongniart, the eldest daughter of
Alexandre Brongniart, the illustrious geologist, an alliance which not
only brought him great happiness, and at the time greatly advanced his
social position, but also in after years made his house one of the chief
resorts of the scientific society of Paris. The many who have shared its
generous hospitality will appreciate how greatly, for more than half a
century, Madame Dumas has aided the work and extended the influence of
her noble husband.
In 1828-'29 Dumas united with Theodore Olivier and Eugene Peclet in
founding the Ecole Centrale des Arts et Manufactures, an institution
which met with great success, and in which, as Professor of Chemistry,
Dumas rendered most efficient service for many years; and in 1878 had
the very good fortune to aid in celebrating the fiftieth anniversary of
his own foundation, and to see it acknowledged as among the most
important and efficient scientific institutions of the world. In 1832
Dumas succeeded Gay-Lussac as Professor at the Sorbonne; in 1835 he
succeeded Thenard at the Ecole Polytechnique; and in 1839 he succeeded
Deyeux at the Ecole de Medecine. Thus before the age of forty he filled
successively, and for some time simultaneously, all the important
professorships of chemistry in Paris except one. This exception was that
of the College of France, with which he was never permanently connected,
although it was there that he delivered his famous course on the History
of Chemical Philosophy, when temporarily supplying the place of Thenard.
Dumas early recognized the importance of laboratory instruction in
chemistry, for which there were no facilities at Paris when he first
came to what was then the center of the world's science; and in 1832
founded a laboratory for research at his own expense. This laboratory,
first established at the Polytechnic School, was removed to the Rue
Cuvier in 1839, where it remained until broken up by the Revolution of
1848. The laboratory was small, and Dumas would receive only a few
advanced students, and these on terms wholly gratuitous. Among these
students were Piria, Stas, Melsens, Leblanc, Lalande, and Lewy, with
whose aid he carried on many of his important investigations. By the
Revolution of 1848 Dumas's activities were for a time diverted into
political channels; but under the Second Empire his laboratory was
re-established at the Sorbonne, and in 1868 was removed to the Ecole
Centrale.
The political episode of Dumas's life was the natural result of an
active mind with wide sympathies, which recognizes in the pressing
demands of society its highest duty. The political and social upheaval
of 1848 seemed at the time to endanger the stability in France of
everything which a cultivated and learned man holds most dear; and Dumas
was not one to consider his own preferences when he felt he could aid in
averting the calamities which threatened his country. Immediately after
the Revolution of February, he accepted a seat in the Legislative
Assembly offered him by the electors of the Arrondissement of
Valenciennes. Shortly afterward the President of the Republic called him
to fill the office of Minister of Agriculture and Commerce. During the
Second Empire he was elevated to the rank of Senator, and shortly after
his entrance into the Senate he became Vice-President of the High
Council of Education. In order to reform the abuses into which many of
the higher educational institutions of Paris had fallen, be accepted a
place in the Municipal Council of Paris, over which he subsequently
presided from 1859 to 1870.
In 1868 Dumas was appointed Master of the Mint of France; but he
retained the office only during a short time, for with the fall of the
Second Empire, in 1870, his political career came to an abrupt
termination. The Senate had ceased to exist, and in the stormy days
which followed, the Municipal Council had naturally changed its
complexion; and even at the Mint, the man who had held such a
conspicuous position under the Imperial government was obliged to vacate
his place. Some years previously he had resigned his professorships
because his official positions were incompatible with his relations as
teacher, and now, at the age of seventy, he found himself for the first
time relieved from the daily routine of official duties, and free to
devote his leisure to the noble work of encouraging research, and thus
promoting the advancement of science. He had reached an age when active
investigation was almost an impossibility, but his commanding position
gave him the opportunity of exerting a most powerful influence, and this
he used with great effect. In early life he had been elected, in 1832, a
member of the Academy of Sciences in succession to Serullas; in 1868 he
had succeeded Flourens as its Permanent Secretary; and in 1875 he was
elected a member of the French Academy as successor to Guizot, a
distinction rarely attained by a man of science.
It was, however, as Permanent Secretary of the Academy of Sciences that
Dumas exerted during the last years of his life his greatest influence.
He was the central figure and the ruling spirit of this distinguished
body. No important commission was complete without him, and on all
public occasions he was the orator of the body, always graceful, always
eloquent. In announcing Dumas's death to the Academy, M. Rolland, the
presiding officer, said:
"Vous savez la part considerable que Dumas prenait a vos travaux et vous
avez bien souvent admire, comme moi, la haute intelligence et la tact
infini avec lesquels il savait imprimer a nos discussions les formes
moderees et courtoises inherentes a sa nature et a son caractere. Sous
ce rapport aussi la perte de Dumas est irreparable et cree dans
l'Academie un vide bien difficile a combler. Aussi, longtemps encore
nous chercherons, a la place qu'il occupait au Bureau avec tant
d'autorite, la figure sympathique et veneree de notre bienaime
Secretaire perpetuel."
And while Dumas was still occupying his conspicuous position in the
Academy, one of the most distinguished of his German contemporaries[L]
wrote of him: "An ever-ready interpreter of the researches of others, he
always heightens the value of what he communicates by adding from the
rich stores of his own experience, thus often conveying lights not
noticed even by the authors of those researches."
[L] A. W. Hofmann, in "Nature," February 6, 1880, to whose admirable
and extended biography the writer is indebted for much of the
material with which this notice has been prepared.
When the writer last saw Dumas, in the winter of 1881-'82, the great
chemist had still all the vivacity of youth, and it was difficult to
realize his age. He took a lively interest in all questions of chemical
philosophy, which he discussed with great earnestness and warmth. There
was the same fire and the same exuberance of fancy which had enchanted
me in his lectures thirty years before. At an age when most men hold
speculation in small esteem, I was much struck with his criticism of a
contemporary, who, he said, had no imagination, although he spoke with
the highest praise of his experimental skill. At that time Dumas showed
no signs of impaired strength. But during the following year his health
began to fail, and he died on the 11th of April, at Cannes, where he had
sought a retreat from the severity of the winter climate of Paris.
Dumas was one of the few men whose greatness can not be estimated from a
single point of view. He was not only eminent as an investigator of
nature, but even more eminent as a teacher and an administrator.
Beginning the study of chemistry at the culmination of the epoch of the
Lavoisierian system, and regarding, as he always did, the author of
that system with the greatest admiration, he nevertheless was the first
to discover the weak point in its armor and inflict the wound which led
to its overthrow. Without attempting to detail Dumas's numerous
contributions to chemical knowledge, we will here only refer to three
important investigations, which produced a marked influence in the
progress of chemical science.
While still in Geneva, Dumas, as has been said, made numerous
determinations of the densities of allied substances, with a view to
discovering the relations of what he called their molecular or atomic
volumes; and it is no wonder to us that the problem proved too complex
to be solved at that time. After his removal to Paris he took up the
much simpler problem which the relations of the molecular volumes of
aeriform substances present, and his paper "On Some Points of the Atomic
Theory," which was published in the "Annales de Chimie et de Physique"
for 1826, had an important influence in developing our modern chemical
philosophy. Gay-Lussac had previously observed, not only that the
relative weights of the several factors and products concerned in a
chemical process bear to each other definite proportions, but also that,
when the materials are aeriform, the relative volumes preserve an
equally definite and still simpler ratio. Moreover, on the physical
side, Avogadro, and afterward Ampere, had conceived the theory, that in
the state of gas all molecules must have the same volume. It was Dumas
who first saw that these principles furnished an important means of
verifying the molecular and atomic weights.
"I am engaged," he writes, "in a series of experiments intended to fix
the atomic weights of a considerable number of bodies, by determining
their density in the state of gas or vapor. There remains in this case
but one hypothesis to be made, which is accepted by all physicists. It
consists in supposing that, in all elastic fluids observed under the
same conditions, the molecules are placed at equal distances, i. e.,
that they are present in them in equal numbers. An immediate consequence
of this mode of looking at the question has already been the subject of
a learned discussion on the part of Ampere"--and Avogadro, as the author
subsequently adds--"to which, however, chemists, with the exception
perhaps of M. Gay-Lussac, appear to have given as yet but little
attention. It consists in the necessity of considering the molecules of
the simplest gases as capable of a further division--a division
occurring in the moment of combination, and varying with the nature of
the compound."
Here, it is obvious, are the very conceptions which form the basis of
our modern chemical philosophy; and at first we are surprised that they
did not lead Dumas at once to the full realization of the consequences
which the doctrine of equal molecular volumes involves in the
interpretation of the constitution of chemical compounds, and to the
clear distinction between "the physically smallest particles" and "the
chemically smallest particles," or the molecules and the atoms, as we
now call the physical and the chemical units. This distinction is
implied throughout Dumas's paper already quoted, and is illustrated by a
striking example in the introduction to his treatise on "Chemistry
applied to the Arts," published two years later; but the ground was not
yet prepared to receive the seed, and more than a quarter of a century
must pass before the full harvest of this fruitful hypothesis could be
reaped.
There were, however, two important incidental results of this
investigation from which chemical science immediately profited. One was
a simple method of determining with accuracy the vapor densities of
volatile substances which has since been known by Dumas's name. The
other was a radical change in the formula of the silicates. On the
authority of Berzelius, who based his opinion chiefly on the analogy
between the silicates and the sulphates, the formula SiO_{3}, had been
accepted as representing the constitution of silica. But from the
density of both the chloride and the fluoride of silicon Dumas concluded
that the formula was SiO_{2}, a conclusion which is now seen to be in
complete harmony with the scheme of allied compounds. To Berzelius,
however, the new views appeared wholly out of harmony with the system of
chemistry which he had so greatly assisted in developing, and he opposed
them with the whole weight of his powerful influence, and so far
succeeded as to prevent their general adoption for many years. Still,
"the new mode of looking at the constitution of silicic acid slowly but
surely gained ground, and it is now so firmly rooted in our convictions,
that the younger generation of chemists will scarcely understand the
pertinacity with which this innovation was resisted."[M]
[M] Hofmann, _loc. cit._
But if this investigation of gas and vapor densities brought a great
strain upon the dualistic system, the second of the three great
investigations of Dumas, to which we have referred, led to its complete
overthrow. The experimental results of this investigation would not be
regarded at the present day as remarkable, and can not be compared
either in breadth or intricacy with the results of numerous
investigations of a similar character which have since been made. The
most important of these results were the substitution products obtained
by the action of chlorine gas on acetic acid. They were published in a
series of papers entitled "Sur les Types Chimiques," and the capital
point made was that chlorine could be substituted in acetic acid for a
large part of the hydrogen without destroying the acid relations of the
product; and the inference was, that the qualities of a compound
substance depend not simply on the nature of the elements of which it
consists, but also on the manner or type according to which these
elements are combined.
To the chemists of the present day these results and inferences seem so
natural that it is difficult to understand the spirit with which they
were received forty years ago. But it must be remembered that at that
time the conceptions of chemists were wholly molded in the dualistic
system. It was thought that chemical action depended upon the antagonism
between metals and metalloids, bases and acids, acid salts and basic
salts, and that the qualities of the products resulted from the blending
of such opposite virtues. That chlorine should unite with hydrogen was
natural, for no two substances could be more unlike; but that chlorine
should supply the place of hydrogen in a chemical compound was a
conception which the dualists scouted as absurd. Even Liebig, the
"father of organic chemistry," warmly controverted the interpretation
which Dumas had given to the facts he had discovered. Liebig himself had
successfully investigated the chemical relations of a large class of
organic products. He had, however, worked on the lines of the dualistic
system, showing that organic substances might be classed with similar
inorganic substances, if we assume that certain groups of atoms, which
he called "compound radicals," might take the place of elementary
substances. In the edition of the organic part of Turner's "Chemistry"
bearing his name, organic chemistry is defined as the "chemistry of
compound radicals," and the formulas of organic compounds are
represented on the dualistic system. Liebig's conceptions were therefore
naturally opposed to those advanced by Dumas; but it is pleasant to know
that the controversy which arose never disturbed the friendly relations
between these two noble men of science, who could approach the same
truth from different sides, and yet have faith that each was working for
the same great end. In his commemorative address on Pelouze, Dumas
expresses toward Liebig sentiments of affectionate regard, and Liebig
dedicates to Dumas, with equal warmth, the German edition of his
"Letters on Chemistry."
By the second investigation, as by the first, although Dumas gave a most
fruitful conception to chemistry, he only took the first step in
developing it. His conception of chemical types was very indefinite, and
Laurent wrote of it, a few years later: "Dumas's theory is too general;
by its poetic coloring, it lends itself to false interpretations; it is
a programme of which we await the realization." Laurent himself helped
toward this realization, and in his early death left the work to his
associate and friend Gerhardt, who pushed it forward with great zeal,
classifying chemical compounds according to the four types of
hydrochloric acid, water, ammonia, and marsh-gas. Hofmann, Williamson,
Wurtz, and many others, greatly aided in this work by realizing many of
the possibilities which these types suggested; and thus modern
Structural Chemistry gradually grew up, in which the types of Dumas and
Gerhardt have been in their turn superseded by the larger views which
the doctrine of quantivalence has opened out to the scientific
imagination. It is a singular fact, however, that, while the growth
began in France, the harvest has been chiefly reaped by Germans; and
that, although in its inception the movement was strongly opposed in
Germany, its legitimate conclusions are now repudiated by the most
influential school of French chemists.
The third great investigation of Dumas was his revision of the atomic
weights of many of the chemical elements, and in none of his work did
he show greater experimental skill. His determination of the atomic
weight of oxygen by the synthesis of water, and of that of carbon by the
synthesis of carbonic dioxide, are models of quantitative experimental
work. To this investigation, as to all his other work, Dumas was
directed by his vivid scientific imagination. In his teaching, from the
first, he had aimed to exhibit the relations of the elementary
substances by classing them in groups of allied bodies; and at the
meeting of the British Association in 1851 he had delighted the chemical
section by the eloquence and force with which he exhibited such
relations, especially triads of elementary substances; such as chlorine,
bromine, and iodine; oxygen, sulphur, and selenium; phosphorus, arsenic,
and antimony; calcium, barium, and strontium: in which not only the
atomic weight, but also the qualities of the middle member of the triad,
were the mean of those of the other two members. Later, he came to
regard these triads as parts of more extended series, in each of which
the atomic weights increased from the first to the last element of the
series, by determinate, but not always by equal differences, the values
being, if not exact multiples of the hydrogen atom according to the
hypothesis of Prout, at least multiples of one half or one quarter of
that weight. There can be no doubt that these speculations were more
fanciful than sound, and that Dumas did not do full justice to earlier
theories of the same kind; but with him these speculations were merely
the ornaments, not the substance of his work, and they led him to fix
more accurately the constants of chemistry, and thus to lay a
trustworthy foundation upon which the superstructure of science could
safely be built.
That exuberance of fancy to which we have referred made Dumas one of the
most successful of teachers, and one of the most fascinating of
lecturers. It was the privilege of the writer to attend the larger part
of two of his courses of lectures given in Paris, in the winters of 1848
and 1851, and he remembers distinctly the impression produced. Besides
the well-arranged material and the carefully prepared experiment, there
was an elegance and pomp of circumstance which added greatly to the
effect. The large theatre of the Sorbonne was filled to overflowing long
before the hour. The lecturer always entered at the exact moment, in
full evening dress, and held to the end of a two hours' lecture the
unflagging attention of his audience. The manipulations were entirely
left to the care of a number of assistants, who brought each experiment
to a conclusion at the exact moment when the illustration was required.
An elegance of diction, an appropriateness of illustration, and a
beauty of exposition, which could not be excelled, were displayed
throughout, and the enthusiasm of a French audience added to the
animation of the scene.
To the writer the lectures of Dumas were brought in contrast to those of
Faraday. Both were perfect of their kind, but very different. Faraday's
method was far more simple and natural, and he excelled Dumas in
bringing home to young minds abstruse truths by the logic of
well-arranged consecutive experiment. With Dumas there was no attempt to
popularize science; he excelled in clearness and elegance of exposition.
He exhausted the subject which he treated, and was able to throw a glow
of interest around details which by most teachers would have been made
dry and profitless.
Two volumes of Dumas's lectures have been published; one comprises his
course on the "Philosophy of Chemistry," delivered at the College of
France in 1836; the other contains only a single lecture, accompanied by
notes, entitled "The Balance of Organic Life," which was delivered at
the Medical School of Paris, August 20, 1841. In both these volumes will
be found the beauty of exposition and the elegance of diction of which
we have spoken, and they are models of literary style. But of course the
sympathetic enthusiasm of the great man's presence can not be reproduced
by written words.
The lecture on "The Balance of Organic Life" was probably the most
remarkable of Dumas's literary efforts. It dealt simply with the
relations which the vegetable sustains to the animal kingdom through the
atmosphere, which, though now so familiar, were then not generally
understood; and the late Dr. Jeffries Wyman, who heard the lecture,
always spoke of it with the greatest enthusiasm.
As might be expected, Dumas's oratory found an ample field in the
Chamber of Deputies and in the Senate; and whether setting forth a
project of recasting the copper coinage or a law of drainage, or
ridiculing the absurd theories of homoeopathy, he riveted the
attention of his colleagues as completely as he had entranced the
students at the Sorbonne.
In the early part of his life, Dumas was a voluminous writer, and in
1828 published the "Traite de Chimie appliquee aux Arts," in eight large
octavo volumes, with an atlas of plates in quarto. But besides this
extended treatise, the two volumes of lectures just referred to are his
only important literary works. He published numerous papers in
scientific journals, which, as we have seen, produced a most marked
effect on the growth of chemical science. But the number of his
monographs is not large compared with those of many of his
contemporaries, and his work is to be judged by its importance and
influence rather than by the extent of the field which it covers.
In his capacity of President of the Municipal Council at Paris, of
Minister of Agricultural Commerce, of Vice-President of the High Council
of Education, and of Perpetual Secretary of the Academy of Sciences,
Dumas had abundant opportunity for the exercise of his administrative
ability, and no one has questioned his great powers in this direction;
but in regard to his political career we could not expect the same
unanimity of opinion. That he was a liberal under Louis Philippe, and a
reactionist under Louis Napoleon, may possibly be reconciled with a
fixed political faith and an unswerving aim for the public good; but his
scheme for "civilian billeting" (by which wealthy people having rooms to
spare in their houses would have been compelled to billet artisans
employed in public works) leads one to infer that his statesmanship was
not equal to his science. Nevertheless, there can be no question about
his large-hearted charity. He instituted the "Credit Foncier," which
flourishes in great prosperity to this day; he also founded the "Caisse
de Retraite pour la Vieillesse," and several other agricultural
charities, which, though less successful, afford great assistance to
aged workmen. Louis Napoleon used to say in jest that the whole of the
War Minister's budget would not have been enough to realize M. Dumas's
benevolent schemes; and once, half-dazzled, half-amused, by one of the
chemist's vast sanitary projects, he called him "the poet of hygiene."
It was to be expected that a man working with such eminent success in so
many spheres of activity, and at one of the chief centers of the world's
culture, should be loaded with medals, and marks of distinction of every
kind. It would be idle to enumerate the orders of knighthood, or the
learned societies, to which he belonged, for, so far from their honoring
him, he honored them in accepting their membership. It is a pleasure,
however, to remember that he lived to realize his highest ambitions and
to enjoy the fruits of his well-earned renown. France has added his name
in the Pantheon
"AUX GRANDS HOMMES LA PATRIE RECONNAISSANTE."