Antoine Laurent Lavoisier
(26th August, 1743 – 8th May, 1794)
"father of modern chemistry"
ANTOINE LAURENT LAVOISIER was born in Paris, August 26, 1743. He was educated under the eye of his
father, a man of opulence, with discernment to appreciate his son's abilities, and liberality to cultivate them
without regard to cost. Lavoisier early showed a decided inclination for the physical sciences ; and before he was
twenty years old, had made himself master of the principal branches of natural
In 1764 the government proposed an extraordinary premium for the best and cheapest project of
lighting the streets of Paris, and other large cities. To this subject, involving a knowledge of several branches
of science, Lavoisier immediately devoted his attention. He produced so able a memoir, full of the most masterly,
accurate, and practical views, that the gold medal was awarded to him. This production was the means of introducing
him into the Academy of Sciences, of which, after a severe contest, he was admitted a member, May 13, 1768; and he
proved himself through life one of its most useful and valuable associates.
At this time the whole range of chemical and physico-chemical science was in an extremely imperfect state; and the
first steps to a more improved system involved the necessity of clearing away a vast mass of error which encumbered
the path to truth. For instance, one of the fanciful ideas, the offspring of the alchemy of the dark ages, which
still continued to haunt the regions of science, was the belief of the conversion of water into earth by gradual
consolidation. This subject Lavoisier treated in the true spirit of the experimental method, and clearly showed
that the pretended conversion was either a deposition of earthy particles, or a sediment arising from the action of
the water on the internal surface of the retort. He also laboured on the analysis of the gypsum found in the
neighbourhood of Paris, and on the crystallization of salts. He discussed the project of conveying water from
L'Yvette to Paris, and the theory of congelation; and to these researches added extensive observations on the
phenomena of thunder and the Aurora Borealis.
He next directed his attention more especially to mineralogy; and made excursions, in conjunction
with Guettard, into all parts of France, endeavouring to form from different districts a complete collection of
their characteristic mineral productions. He made advances towards a systematic classification of facts connected
with the localities of fossils, which afterwards served as the basis of his work on the revolutions of the globe
and the formation of successive strata, of which two admirable abstracts were inserted in the Memoirs of the
Academy of Sciences, for 1772 and 1787.
Thus during the earlier part of his life, Lavoisier does not seem to have devoted himself in
particular to any one branch of science. But about the year 1770 the announcement of the existence of more than one
species of gaseous matter, arising out of the successive researches of Black, Scheele, Priestley, and Cavendish,
had the effect of fixing his attention to the subject of pneumatic chemistry. The invaluable discoveries just
alluded to had opened a new world to the inquirer into nature; and the labours of those distinguished
experimentalists had conspired to commence a fresh era in science. Lavoisier was one of the first to appreciate at
once the importance of the results they had arrived at, and the immense field of further research to which those
results had opened the way. He perceived by a sort of instinct the glorious career which lay before him; and the
influence which this new science thus, as it were, created, must have over every sort of physical research.
Priestley possessed precisely those qualifications which are most available for striking out new and brilliant
discoveries of facts ; a boundless fertility of invention; a power of rapidly seizing remote analogies; and an
equal readiness in framing and in abandoning hypotheses, which have no value, but as guides to experiment.
Lavoisier, less eminent in these respects, possessed in a more peculiar degree the mental characteristics which
enable their owner to advance to grand generalizations and philosophical theories upon the sure basis of facts.
He possessed, in its fullest sense, the true spirit of inductive caution, and even geometrical
rigour; and his observations, eminently precise and luminous, always pointed to more general views.
In 1774, he published his Opuscules Chimiques,' in which, after a full and truly philosophical examination of the
labours of preceding experimenters in the discovery of the gases and their characteristic properties, he proceeds
to describe his own beautiful and fundamentally important researches, from which resulted the True Theory of
Combustion,' which may be termed the very sun and centre of the whole modern system of chemistry.
To the vague dreams of the alchemist had succeeded the remarkable theory of Hooke, who maintained
that a certain ingredient of the atmospheric. air (which also enters as an ingredient into several other bodies,
especially nitre) was the solvent which absorbed a portion of the combustible. This process was continued in
proportion as more of the solvent was supplied. The solution took place with such rapidity, as to occasion those
motions or pulsations in which Hooke believed heat and light to consist.
This near approach to the truth was thrown into discredit by the more brilliant and imposing theory
of Stahl, who captivated the imaginations of chemists by his doctrine of phlogiston, the principle or element of
fire, a sort of metaphysical something, which conferred the property of being combustible. Stahl taught that the
process of combustion deprived bodies of their phlogiston, which, in the act of separation, exhibited its latent
energies in the evolution of light and heat.
This wild chimera long maintained its ground, and received successive modifications in the hands of
several distinguished chemists, the most important of which was that of Kirwan; but these all retained the
fundamental error that something was abstracted from the burning body. Yet Rey, so early as 1630, and Bayer
afterwards, had both shown that metals by calcination increase in weight, or have something added to them.
Lavoisier turned his attention to the defects of the existing theory about 1770; and the last-named experiments
probably directed him more specifically to the essential point of the inquiry. He pursued his researches with
unwearied industry; and by a long series of experiments of the most laborious and precise nature, he succeeded in
determining that, in all cases of combustion, that substance which is the real combustible invariably receives an
addition, or enters into a new combination ; and the matter with which it combines is in all cases that same
substance which had now been shown by Priestley to be one of the constituents of the atmosphere, and which was then
known by the name of vital air.
It was however long before Lavoisier gained a single convert. At length M. Berthollet, at a meeting
of the Academy in 1785, publicly renounced the old opinions and declared himself a convert. Fourcroy followed his
example. In 1787, Morveau, during a visit to Paris, became convinced, and declared the conclusions of Lavoisier
irresistible. The younger chemists speedily embraced the new views; and their establishment was thus complete.
There only remained some lurking prejudices in England, where the Essay of Kirwan retained its credit. Lavoisier
and his coadjutors translated this essay into French, accompanying each section by a refutation. So completely was
this done, that the author himself was convinced; and, with that candour which distinguishes superior minds, gave
up his views as untenable, and declared himself a convert.
These discoveries introduced Lavoisier to the notice of the most eminent persons in the State; and
in 1776, Turgot engaged him to superintend the manufacture of gunpowder for the Government. He introduced many
valuable improvements in the process, and many judicious reforms into the establishment.
In 1778, Lavoisier having been incessantly engaged on the subject of gases and combustion, announced another great
discovery, " that the respirable portion of the atmosphere is the constituent principle of acids," which he
therefore denominated oxygen.
The question as to " the acidifying principle " had long formed the subject of discussion. The
prevalent theory was that of Beecher with various modifications, which made the acid principle a compound of earth
and water regarded as elements. Lavoisier found in the instance of a great number of the acids, that they consisted
of a combustible principle united with oxygen. He showed this both analytically and synthetically, and hence
proceeded to the conclusion that oxygen is the acidifying principle in all. acids. Berthollet opposed this
doctrine, and contended that, in general, acidity depended on the manner and proportion in which the constituents
are combined. The fact is, that, in this instance, Lavoisier had advanced a little too rapidly to his conclusion.
Had he contented himself with stating it as applying to a great number of acids, it would have been strictly true ;
but lie had certainly no proof of its being universally the case. When Sir H. Davy, some years after, showed that
one of the most powerful acids (the muriatic) does not contain a single particle of oxygen, and when the researches
of Guy Lussac and others had exhibited other proofs of the same thing, it became evident that Lavoisier's assertion
required considerable modification. And though nearly all acids have been since included under the general law of
containing some supporter of combustion, yet there appear to be exceptions even to this ; the cautious language of
Berthollet has been completely justified; and a perfect theory of acidity is perhaps yet wanting. Nevertheless,
Lavoisier's discovery is one of first-rate magnitude and importance, and with this qualification, certainly forms
the basis of all our present knowledge of the subject.
Another important research in which Lavoisier engaged, in conjunction with Laplace, was the
determination of the specific heats of bodies, by means of an ingenious apparatus, which they denominated the
calorimeter : these were by far the most precise experiments on the subject which had as yet been made, though some
inaccuracies in the Method have since been pointed out.
Lavoisier owed much, it must be owned, to those external advantages of fortune, the absence of
which, though it cannot confine the flights of real genius, yet may seriously impair the value and efficiency of
its exertions; and the presence of which, though it cannot confer the powers of intellect, may yet afford most
invaluable aids to the prosecution of research, and the dissemination of knowledge. In the instance before us,
these advantages were enjoyed to the full extent, and turned to the best use. Lavoisier was enabled to command the
most unlimited resources of instrumental aid ; he pursued his researches in a laboratory furnished with the most
costly apparatus, and was able to put every suggestion to the test of experiment, by the assistance of the most
skilful artists, and instruments of the most perfect construction.
But as he could thus command these essential advantages for the prosecution of his own investigations, he was
equally mindful of the extension of similar advantages to others : he always evinced himself ready to assist the
inquiries of those who had not the same means at their disposal ; and was no less liberal in aiding them by his
stores of information and able advice. Indeed no one could be more sensible how much there is of mutual advantage
in such intercourse between those engaged in the same scientific labours ; and this conviction, joined with a full
perception of the immense benefits accruing from personal acquaintance among men of kindred pursuits, and the
interchange of social good offices, led him to the regular practice of opening his house on two evenings in every
week, for an .assembly of all the scientific men of the French capital ; which very soon became a point of general
resort and reunion to the philosophers of Europe.
At these meetings general discourse and philosophic discussion were agreeably intermingled; the
opinions of the most eminent philosophers were freely canvassed ; the most striking and novel passages in the
publications of foreign countries were made known, recited, and animadverted upon; and the progress of experiment
was assisted by candid comments and comparison with theory. In these assemblies might be found, mingling in
instructive and delightful conversation, all those whose names made the last century memorable in the annals of
science. Priestley, Fontana, Landriani, Watt, Bolton, and Ingenhouz, were associated with Laplace, Lagrange, Borda,
Cousin, Monge, Morveau, and Berthollet. There was also an incalculable advantage in bringing into communication and
intimacy men engaged in distinct branches of science : the intercourse of the mathematician with the geologist, of
the astronomer with the chemist, of the computer with the experimenter, and of the artist with the theorist, could
not fail to be of mutual advantage. In no instance were the beneficial effects of such intercourse more strikingly
displayed than in the chemical sciences ; which, from this sort of comparison of ideas and methods, began now to
assume a character of exactness from an infusion of the spirit of geometry ; and a department hitherto abandoned to
the wildest speculations, and encumbered with the most vague and undefined phraseology (derived from the jargon of
the alchemists), began to assume something like arrangement and method in its ideas, and precision and order in its
nomenclature. This influence was strongly marked in the physical memoirs produced in France from this period
downwards. The precision and severity of style, and the philosophical method of the mathematicians, was insensibly
transfused into the papers of the physical and chemical philosophers.
Lavoisier individually profited greatly by the sources of improvement and information thus opened.
Whenever any new result presented itself to him, which, perhaps, from contradicting all received theories, seemed
paradoxical, or at variance with all principles hitherto recognised, it was fully laid before these select
assemblies of philosophers ; the experiment was exhibited in their presence, and they were invited with the utmost
candour to offer their criticisms and objections. In perfect reliance on the mutual spirit of candour, they were
not backward in urging whatever difficulties occurred to them, and the truth thus elicited acquired a firmness and
stability in its public reception proportioned to the severity of the test it had undergone. Lavoisier seldom
announced any discovery until it had passed this ordeal.
At length he combined his philosophical views into a connected system, which he published in 1789,
under the title of Elements of Chemistry :' a beautiful model of scientific composition, clear and logical in its
arrangement, perspicuous and even elegant in its style and manner. These perfections are rarely to be found in
elementary works written by original discoverers. The genius which qualifies a man for enlarging the boundaries of
science by his own inventions and researches is of a very different class from that which confers the ability to
elucidate, in a simple and systematic course, the order and connexion of elementary truths. But in Lavoisier these
different species of talent were most happily blended. He not only added profound truths to science, but succeeded
in adapting them to the apprehension of students, and was able to render them attractive by his eloquence.
In 1791 he entered upon extensive researches, having for their object the application of pneumatic
chemistry to the advancement of medicine, in reference to the process of respiration. With this view he examined in
great detail the changes which the air undergoes, and the products generated in that process of the animal economy.
He had previously, however, as far back as 17-0, detailed a series of experiments to determine the quantity of
oxygen consumed and carbonic acid generated by respiration, in a given time, in the Memoirs of the French
In the twenty volumes of the Academy of Sciences, from 1772 to 1793, are not less than forty
memoirs by Lavoisier, replete with all the grand phenomena of the science :—the doctrine of combustion in all its
bearings ; the nature and analysis of atmospheric air ; the generation and combinations of elastic fluids ; the
properties of heat ; the composition of acids ; the decomposition and recomposition of water ; the solutions of
metals ; and the phenomena of vegetation, fermentation, and animalization. These are some of the most important
subjects of his papers ; and during the whole of this period he advanced steadily in the course which was pointed
out to him by the unerring rules of inductive inquiry, to which his original genius supplied the commentary. So
well did he secure every point of the results to which he ascended, that he never made a false step. It was only in
one subject, before alluded to, that he may be said to have gone a few steps too far. Nor did he ever suffer
himself to be discouraged, or his ardour to be damped by the difficulties and obstacles which perpetually impeded
his progress. He traced new paths for investigation, and founded a new school of science; and his successors
had ample employment in following out the inquiries which he had indicated, and exploring those recesses to which
he had opened the way.
In the relations of social and civil life Lavoisier was exemplary ; and he rendered essential service to the state
in several capacities. He was treasurer to the Academy, and introduced economy and order into its finances : he was
also a member of the board of consultation, and took an active share in its business. When the new system of
measures was in agitation, and it was proposed to determine a degree of the meridian, he made accurate experiments
on the dilatation of metals, in conjunction with Laplace (1782), to ascertain the corrections due to changes of
temperature in the substances used as measuring rods in those delicate operations.
By the National Convention he was consulted on the means of improving the manufacture of assignats,
and of increasing the difficulty of forgery. He turned his attention to matters of rural economy, and, by improved
methods of cultivation, on scientific principles, he increased the produce of an experimental farm nearly one half.
In 1791 he was invited by the Constituent Assembly to digest a plan for simplifying the collection of taxes the
excellent memoir which he produced on this subject was printed under the title of The Territorial Riches of
France.' He was likewise appointed a Commissioner of the National Treasury, in which he effected some beneficial
During the terrors of Robespierre's tyranny, Lavoisier remarked that he foresaw he should be
stripped of all his property, and accordingly would prepare to enter the profession of an apothecary, by which he
should be able to gain a livelihood. But the ignorant and brutal ruffians who were then in power had already
condemned him to the scaffold, on which he was executed, May 8, 1794, for the pretended-crime of having adulterated
snuff with ingredients destructive to the health of the citizens ! On being seized, he entreated at least to be
allowed time to finish some experiments in which he was engaged ; but the reply of Coffinhall, the president of the
gang who condemned him, was characteristic of the savage ignorance of those monsters in human form :—" The Republic
does not want savans or chemists, and the course of justice cannot be suspended.".
Lavoisier in person was tall and graceful, and of lively manners and appearance. He was mild,
sociable, and obliging ; and in his habits unaffectedly plain and simple. He was liberal in pecuniary assistance to
those in need of it ; and his hatred of all ostentation in doing good probably concealed greatly the real amount of
his beneficence. He married, in 1771, Marie-Anni-Pierrette Paulze, a lady of great talents and accomplishments, who
after his death became the wife of Count Rumford.