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by copyright: Antoine
Danchin © 2000 & Disclaimer.
These pages represent a biased
choice of dates relevant to biology, obtained by compiling a
great many different sources, often using the original texts
and not the WWW; the information collected here
does not use Wikipedia which, by construction,
relies on a process akin to a vote, and changes over time in
order to reflect some kind of a popular consensus about knowledge
rather than accurate knowledge. Care has been taken
to check information and rewrite it when needed; direct
access links to the original sources is provided whenever possible;
however date records still contain many errors; the links are
chosen to be as diverse as possible, they do not engage the responsability
of the author. Note however that many WWW links are generally
unstable, so that many might be obsolete despite regular checks.
Note that the links
in French and in English may differ. Notez que les liens en
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Please send comments and corrections here.
ca 1800 In his lectures,
Karl Friedrich Kielmayer (1765 - 1844), a teacher
of Cuvier in Stuttgart who never allowed publication
of any of his work, places emphasis on the comparative study
1800 Alessandro Volta (Como
1745 - Pavia 1827) invents the wet cell battery aptly named a "pila".
He is made "Comte" by Napoléon for this invention
a year later.
1800-1804 Nicolas Thomas Baudin (Ile
de Ré, France, 1754 - Ile Maurice, 1803) commands a French
scientific, strategic and economic expedition to New Holland
(Terra Australis: Australia) associating the corvette Galatée,
renamed Le Géographe and the much slower storeship Ménacarte renamed Le
Naturaliste. More than a dozen scientists were on board
, when leaving France but several investigators and crews deserted
at the first stop at Ile-de-France (Mauritius). After exploring
the west of Terra Australis during the winter 1801, the expedition
goes north to Timor, then south to Tasmania. Because of their
large difference in speed the ships separate, while Le Géographe meets
the English exploring ship Investigator, commanded by
Matthew Flinders and in the winter of 1802 reaches the English
penal colony in Port Jackson. Le Naturaliste is sent
back to France in November 1802 with all collections made so
far. Thereafter Le Géographe continues together
with the locally built Casuarina along the south Australian
coast, reaching King George Sound in February 1803 and Timor
in May, where the only left botanist stays until 1807 because
of illness. In September 1803 Baudin dies at
Ile de France and the Casuarina is abandoned there.
In March 1804 Le Géographe reaches France with
the collections made after that Le Naturaliste had left
1801 Lamarck uses
"biologie" (from the Greek βιος,
life, and λογος, law, reason) to denote
the study of living organisms in his work Hydrogéologie.
He is among the last scientists to see life within the frame
of pre-atomic physics. This explains much of the misunderstandings
about his way to see evolution.
meets the rebellion of François
Dominique Toussaint Louverture (Bréda
ca 1743 - Fort de Joux 1803) in the Carribean, and 27,000 soldiers
under General Charles LeClerc die there of Yellow Fever. This
decides of the selling of Louisiana to the United States of America.
François-Xavier Bichat (Thoirette 1771 - Lyon 1802) publishes
his Traité d'anatomie descriptive. Despite
his young age he introduces a new system into the science
of anatomy. Assuming that the true essence of life is inaccessible,
he states that one has to study it through the phenomena
it manifests, either normal or pathological. He insists on
the importance of structure, which he makes a corner-stone
of biology. He distinguishes twenty one types of tissues:
cellular (connective tissue), nervous tissue, arterial, venous,
the exhalation tissue, absorbent, bone tissue, medullary
tissue (in the bones), cartilaginous, fibrous, fibrocartilaginous,
animal muscle, organic muscle, mucous tissue, serous tissue,
synovial tissue, glandular, dermoid, epidermoid and finally
capillary. In his work he makes experiments to distinguish
between organic sensibility (receiving an impression) and
animal sensibility (which in addition conveys the impression
to a common centre).
1801 Jean-Antoine Claude Chaptal (Nogaret,
Lozère, 1756 - Paris, 1832) after having improved the
production of sugar by beet roots, publishes the Art de faire,
de gouverner, et de perfectionner les vins, where he invents
the process now named "chaptalization"
meant to enhance the alcoholic degree of wine by sugar addition.
Marco Antonio Caldani (Bologna, 1725 - Padova,
1813) and his nephew Floriano Caldani publish
a monumental illustrated reference work on human anatomy, Icones
anatomicae quotquot sunt celebriores ex optimis neotericorum
operibus summa diligentia depromptae et collectae; Iconum
who had started his career at the age of fifty, nominated by
the French Revolution National Convention at the Jardin des Plantes,
as a zoologist specialist of invertebrates (although he had mostly
be interested in plants) elaborates a theory of evolution based
on heritable modification of organs through continued use and
loss through disuse, which he publishes in his Recherches
sur l'organisation des corps vivants. There, basing his theory
on the analysis of the progression of organ structures in different
species, he states that it is important to consider not individuals,
but classes (following Vicq
d'Azyr) and states that it is not the organs which
have given rise to the habits of animals, but the habits and
manners of life which have fashioned the body forms (hence visible
variations in populations, and progressive variations in different
species). This is of course exactly the opposite of what could
be found in ancient atomist theories (for example in Lucretius De
Rerum Natura), as well as in the work of Empedocles.
The active principle of modification is the "feu éthéré"
which gives an "orgasme vital", a state of tension,
which maintains all parts of the body in a given (moving) shape.
This fire is transmitted upon fertilization from the male sexual
product to the embryo. This fire exists everywhere in Nature,
and is therefore the cause of the spontaneous generation of life...
This shows that Lamarck thought is deeply impregneted by the
theory of the four elements, not yet influenced by the renewal
of the atomist theory, with the new chemistry of Lavoisier.
Jean Georges Cabanis (Cosnac 1757 - Rueil-Malmaison
1808) repeatedly states (Rapports du physique et du moral
de l'Homme), as did Locke and Condillac, that all ideas
are based on sense-impressions.
1802 Bichat dies from a malignant fever at
a time when his Traité
des membranes is published.
Young (Milverton 1773 - London 1829) proposes
a trichromatic theory of color vision, based on three separate
receptor substances in the retina.
1802 Charles François Brisseau de
Mirbel (1776 - 1854) professor of Botany at the Jardin
des Plantes in Paris, concludes from his microscopic observations
of plants that the plant is wholly formed of a continuous cellular
1802-1822 In parallel with Lamarck, Gottfried Reinhold Treviranus (1776-1837)'s
monumental Biologie oder Philosophie de Lebended Natur,
speads the word biology. Treviranus introduced
the notion of biology as a distinct discipline into Germany and
was one of the first to express the idea that the cell is the
structural unit of living matter.
Berthollet (Talloires 1748 - Arcueil
1822) publishes his Essai de statique chimique. With Fourcroy and Guyton
de Morveau (Dijon 1737 - Paris 1816), he had followed
the lessons of Lavoisier, and had improved
the technique of dying. He also established the composition
of prussic acid (hydrogen cyanide) and of hydrogen sulfide.
He discovered sodium hypochlorite and potassium chlorate.
1803 The discovery of iridium (named after
Iris, goddess of the rainbow, because of the variegated colour
of its salts) and osmium (from the Greek word for "odour," because
of the chlorine-like odour of its volatile oxide), later used
for electron microscopy is claimed by the English chemist Smithson
Tennant (1761-1815). The French chemists Hippolyte-Victor Collet-Descotils (Caen,
1773 - 1815), Antoine François de
Fourcroy (Paris, 1755 - 1809), and Nicolas Louis Vauquelin (Saint-André-dHébertot
1763 - 1829) identify the two metals at about the same time.
Théodore de Saussure (Genève
1767 - 1845) publishes in his Recherches chimiques sur la
végétation, experiments that represent the
first treatment of the subject of photosynthesis using quantitative
methods and modern chemical terminology. He develops there
the first balanced equation for the process.
1804 Building on the work of Proust, John
1766 -1844) enunciates his atomic theory (hence the mass
unit created after his name, the Dalton, mass of the hydrogen
Aldini (Bologna, 1762 - Milano; 1834) dedicates
to Bonaparte his
"Essai théorique et expérimental sur le
galvanisme, avec une série d'expériences faites
en présence des commissaires de l'Institut National de
France, et en divers théâtres anatomiques de Londres".
This work relates experiments on a hanged man in London, and
in Calais on work demonstrating galvanism across the sea. The
effects of galvanism on the animal system, the velocity of electricity
through water, electrical fishes and the conductivity of flames
1805 Father of preventive medicine, Parmentier imposes
vaccination for Napoléon soldiers.
1805 Friedrich Wilhelm Adam Serturner (1784-1841)
isolates from opium a substance he called morphine (after Morpheus,
the Greek God of sleep).
1805 Georges Cuvier publishes
the last of his "Leçons sur l'Anatomie Comparée",
which, although much influenced by his predecessors Daubenton and
chiefly Vicq d'Azyr introduce that subject.
In this work he acknowledge the importance of the new chemistry
and enumerates the atoms of the body: carbon, hydrogen, oxygen
and nitrogen, pointing out the major importance of the latter
in animals, as compared to plants. The correlation between the
separate organs in the same body, that Vicq d'Azyr had
already described in its main features is studied in details
by Cuvier, and to him represents the very basis of his conception.
Brongniart (Paris 1770-1847)'s "Essai
d'une Classification Naturelle des Reptiles", started
in 1800, and which provides a new way to class these animals,
is not published in full until 1803. It appears in the volume
of the Mémoires presentés à l'Institut
par divers Savans for 1805.
1805 Ludolf Christian Treviranus (1779-1864)
proposes that spermatozoa play a role analogous to that of the
pollen of plants.
Nicolas de Corvisart des
Marets (1755-1821) translates von
Augenbrugg work on chest percussion and establishes
general principles of cardiology (Essais sur les maladies
du coeur et des gros vaisseaux).
1806 Vauquelin and Pierre Jean Robiquet (1780
- 1840) isolate the first amino-acid, asparagine, from asparagus.
Jacob Berzelius (Väversunda 1779
- Stockholm 1848), known as one of the creators of chemistry,
expounds in his Lectures on Animal Chemistry that life
does not lie in any extraneous essence deposited in an organic
or living body, but must be sought in the common fundamental
forces of primal elements.
1807 Isaac Bénédict Prévost (Genève,
1755 – 1819) shows that an organism is responsible for
wheat bunt disease and that copper salts can prevent the disease.
Péron (Cerilly, 1775 - 1810) and Charles-Alexandre
LeSueur (Le Havre, 1778 - Le Havre, 1846) who
had joined Baudin's expedition to New Holland
in charge of works as diverse as anatomy, anthropology, botany,
zoology, meteorology, oceanography and naval hygiene publish
the first volume of Voyage de découvertes aux
Terres Australes. Together they collect more than 100,000
zoological specimens (including many live species).
Baptiste Joseph Fourier (Auxerre
1768 - Paris 1830) was nominated in 1794 to study in Paris,
at the Ecole Normale which opened in January 1795. He was
taught there by Lagrange, Laplace and Monge. While in Egypt
with Napoleon, Fourier helped found the Cairo Institute.
In 1807 he submits a memoir on the cooling of infinite
solids and terrestrial and radiant heat, later used by Lord
Kelvin to calculate the age of the Earth.
1807 Jean-Baptiste Louis Claude Theodore Leschenault
de la Tour (Chalon-sur-Saône, 1773 - 1826) medical
doctor and naturalist became botanist in-chief in Baudin's
expedition to Australia on Le Géographe and Le
Naturaliste (1800 - 1803). Left sick at
Timor in June 1803 in was back in France in July 1807 he started
description of a large collection of plants and birds that were
later on discussed by contemporary naturalists. His herbarium
is still at the Natural History Museum in Paris.
1808 In his Exposition et défense de
ma théorie végétale Mirbel shows that
plants consist of cells, whose parts are continuous and form
a single membranous fabric. He states that the cellular nature
is the basis of all structures in the plant kingdom, thus predating
the cell theory that was about to be born.
Joseph Gall (Baden 1758 - Paris 1828)
in his Recherches
sur le Système nerveux et sur celui du cerveau en particulier publishes
the first work on the science of the shape of the skull (cranioscopy,
later known as phrenology).
1809 Reil uses
alcohol to preserve the brain by hardening.
1809 Lamarck investigates the microscopic structure
of plants and animals. He remarks that it has been recognized
for a long time that the membranes which form the envelopes of
the brain, of the nerves, of vessels, of all kinds of glands,
of viscera, of muscles and their fibers, and even the skin of
the body are in general the productions of cellular tissue. But
no one, so far as I know, has yet perceived that cellular tissue
is the general matrix of all organization and that without this
tissue no living body would be able to exist, nor could it have
been formed. Lamarck's Philosophie Zoologique reviews
the animal system and emphasizes the fundamental unity of life
and the capacity of species to vary under environmental influences
dominated by stressing conditions. Lamarck draws up the invertebrate
system where he distinguishes Infusoria from the Polypi, and
the Cirripedia from the Mollusca, getting ten invertebrate classes,
most of which are still retained today: Infusoria, Polypi, Radiata,
Vermes, Insecta, Arachnida, Crustacea, Annelida, Cirripedia and
the French chef, completes his experiments demonstrating a procedure
for preservation of foods by canning.
1809 Lorenz (Okenfuss) Oken (1779
- 1851) publishes his Naturphilosophie, where he extends
the romantic imaginative description of life. His theories were
reserved to a cultural elite and were supposed to be unattainable
for the majority (this is reminiscent of Pythagoras).
Oken created the journal Isis and founded theosophy which
became a focus for "scientific" life in Germany.
1809 Luigi Rolando (Torino, 1773 - 1831) works
on the brain of birds and uses galvanic current to stimulate
Hyde Wollaston (East Dereham 1766 - London
1828) known for his discovery of rhodium and palladium, isolates
the second amino-acid, cystine, from a bladder stone.
Friedrich Samuel Hahnemann (Meissen, Germany,
1855 - Paris, 1843) publishes a book Organon der Heilkunst (Organon
of the Healing Art) that had to have a considerable commercial
influence through the creation of a whole field of paramedical
practices. Based on the pre-scientific concept of cure: "similia
similibus curantur" (or like is cured by like), Hahnemann creates
homeopathy (from the Greek ὁμοιος,
same and παθος, suffering). It is interesting to note
that this approach has spread throughout the world despite
its conflict with the observations and concepts of physics
and chemistry (existence of atoms). This is because, in spite
conclusions established from the outset, the approach is
both harmless as such (it can be dangerous because it involves
the failure to help a person in danger, if there exists an
treatment that works) and very lucrative.
Louis Gay-Lussac (Saint Léonard
de Noblat 1778 - Paris 1850) deduces the equation for alcoholic
fermentation C6H12O6 --> 2
C2H5OH + 2 CO2.
1811 The pharmacist and chemist Henri
Braconnot (Commercy 1780 - Nancy 1855) isolates
from mushrooms a compound that will be identified from insects
in the 1830s, and will be called chitin.
1811 César Julien Jean LeGallois (1770-1840?)
discovers respiratory center in the medulla. LeGallois considers
the feasibility of artificial circulation.
Romano Amedeo Carlo Avogadro (Torino
1776 - 1856) proposes in the Journal de Physique that
a fixed number of molecules of any gas will equal the molecular
weight of the gas in grams. This was not widely accepted until
Bell (Edinburgh 1774 - London 1842) in his Idea
of a New Anatomy of the Brain and François
Magendie (Bordeaux 1785 -Sannois 1855) in his
numerous lectures and publications discover the functions
of the dorsal and ventral roots of spinal cord. Magendie
worked on live animals, which was perceived with horror by
some of his contemporaries. Magendie strongly opposes Bichat's
vitalism. In general he considers hypotheses as useless,
facts alone having any scientific value.
1812 Georges Cuvier's important
study Recherches sur les ossemens fossiles des quadrupèdes [Research
on the Fossil Bones of Quadrupeds] is first published.
1813 Augustin Pyrame de
Candolle (Genève 1778 - 1841) publishes
élémentaire de la botanique in which he states
that life is dominated by four great forces: attraction and affinity,
which are at the root of the physico-chemical properties of life,
and life-force and sensibility, which are specific to life, the
latter being restricted to animals. He repudiates Lamarck's hypothesis
of a single evolutionary chain of organisms. He defines a species
by the collection of all the individuals which resemble more
each other than others, are capable of mutual fertilization producing
fertile individuals and are multiplied by generation so that
it is reasonable by analogy to assume that they descend from
one single individual. In this work he uses the suffix
"-blaste" to describe part of the plant embryo.
This suffix will subsequently be used generally.
1814 André-Marie Ampère (1775
- 1836), independently of Avogadro, discovers
the same concept that a fixed number of molecules of any gas
will equal the molecular weight of the gas in grams, that he
publishes in the Annales de Chimie, together with a
breakthrough of prime importance: molecules are represented as
simple polyhedra in which atoms occupy the corners, the polyhedron
representing "la forme représentative de la particule" (the
representative shape of the molecule).
1814 Saussure quantifies alcoholic fermentation.
Joachim Henri Dutrochet (Néon
1776 - Paris 1847) publishes his investigations into animal development,
suggesting a unity of the main features during the early stages.
Later research into plant and animal physiology allows him to
state that respiration is similar in both plants and animals.
1815 Konstantin Sigizmundovich (Gottlieb) Kirchhof (Teterow
1764 - 1833), who had discovered glucose, reports, after having
chemically hydrolyzed starch, that a glutinous component of wheat
is also capable of converting starch to dextrin and sugar.
1815 Lamarck publishes his Histoire naturelle
des animaux sans vertèbres.
Biot (Paris 1774 - Paris 1862) later a teacher
of Louis Pasteur, discovers optical activity.
Biot was a voluntary during the 1792 war against the monarchists
Allies against France. He recognized the celestial origin
of meteorites in 1803 and completed the measurement of the
earth meridian started by Jean-Baptiste Delambre (1749-1822)
and Pierre Mechain (1744-1804). He nade
the first precise measurements of the density of gases with François
Arago (1756-1853) and evaluated the value of the
magnetic field created by a linear current with Félix
Savart (1791-1841) (Biot-Savart law). His most
important contribution for biology is the definition of the
laws governing polarisation of light, which he taught to Louis
1816 René Théophile
Hyacinthe Laënnec (1781-1826) replaces
direct auscultation by the use of the stethoscope, and introduces
terms such as pectoriloque, ronchi, crépitations (Traité de
l'Auscultation médiate, 1818). The instrument's
daily use by an increasing number of clinicians was to yield
a crop of murmers and other signs of cardiac and pulmonary
Wollstonecraft Shelley (Somers
Town 1797 - Bournemouth 1851) writes Frankenstein, a romantic
prefiguration of biological engineering. The hero monster
is usually taken for Dr Victor Frankenstein. The book is published
two years later.
1817 James Parkinson (London 1755 - 1828) publishes An
Essay on the Shaking Palsy, where he describes the neurological
disorder we now know to be due to a lack of dopamine, later
known as Parkinson's disease.
1817 Christian Heinrich Pander (Riga
1794 - Saint-Petersburg 1865) known as the founder of conodont
paleontology, first describes the existence of three germ layers
in chick embryos (later named Blätter by Wolff).
The concept was later extended by Karl Ernst
von Baer to include all vertebrates.
Smith (Churchill 1769 - Northampton 1839)'s Stratigraphical
System of Organized Fossils shows that certain geological
strata have characteristic series of fossils.
1817 In Cuvier's Le Règne
d'après son organisation, the animal kingdom is divided
into four groups Vertebrata, Mollusca, Articulata and Radiata,
having each a special ground-plan. This is probably at the root
of most of today's metaphors using the concept of "blueprint" (rather
than the more appropriate concept of program, or of book of recipe).
1817 Joseph Bienaimé Caventou (1795
– 1877) and Pierre
Joseph Pelletier (Paris, 1788 – Paris, 1842)
isolate chlorophyll from plant leaves: published in Sur la
matière verte des feuilles.
Wilhelm Friedrich Hegel (Stuttgart 1770
- Berlin 1831) publishes his Encyclopedia,
where he describes the nature of Logic and of Organic Matter.
1817 Georg August Goldfuss (1782-1848)
coins the name "protozoa"
to describe animalcules present in water. The term was only formally
accepted in 1920. He subsequently includes the Cnidaria into
Jacques Thénard (Louptière 1777 - Paris 1857) publishes
de Chimie Elémentaire Théorique et Pratique, where
he tries to understand the role of iron in hématosine (hemogloblin).
This treaty was republished and amended many times later on. A
year later he discovers hydrogen peroxide.
1818 The Library of the Surgeon General's Office
is established in the USA (later to become the Army Medical Library
and then the National Library of Medicine).
1819 Arthur Jacob (1790 - 1874) describes the
layer of the retina containing the rods and cones (in the Philosophical
1819 Proust identifies a molecule he names
acide caséeux, and that we know today as the amino
Charles Adélaïde (Adelbert von) Chamisso de
Boncourt (Château de Boncourt 1781 - Berlin 1838),
known as a romantic poet and writer, and as a botanist and
philologist, introduces the concept of alternation
of generations (corresponding to meiosis and fertilisation).
Friedrich Nasse (Bielefeld 1778 - Marburg
1851), a figure of romantic anthropology, formulates the law
which brings now his name: hemophilia occurs only in males
and is passed on by unaffected females.
1820 Braconnot obtains from rotten cheese aposépédine which
is none other than acide caséeux identified the previous year
(leucine). He also creates a gelatin derivative he names glycocolle,
and we know today as the amino acid glycine.
1820 The galvanometer, named after Galvani,
is invented by Johann Salomo Christoph Schweigger (1779
- 1857). It is the first sensitive instrument for measuring and
detecting small amounts of electricity.
1820 Caventou and Pelletier isolate
quinine from the bark of Cinchona trees. They later
isolate strychnine and brucine.
1821 Charles Bell describes facial paralysis.
Although he reported several cases of facial paralysis, the condition
now named as Bell’s palsy
was not part of these early descriptions.
In contrast, Nicolaus Anton Friedreich (1761–1836) of Würzburg
(Germany) wrote an extensive thesis in 1797 about a condition,
which he called Rheumatic Facial Paralysis and which is clearly
what is named today Bell's palsy.
1821 Karl Asmund Rudolphi (Stockholm
1771 - Berlin 1832) founder of Berlin's zoological museum, publishes
his Grundriss der Physiologie, where he states that the
human genus should be divided into species, not into races. In
this connexion, he declares that human beings cannot have derived
from a single pair. His work is therefore at the root of "scientific"
racism in German and Scandinavian countries, well before the
1821 Magendie discusses functional differences
between dorsal and ventral roots of the spinal cord.
1821-1823 Jean-Louis Prévost (?1790
– 1850) and Jean-Baptiste André Dumas (Alès
1800 - Cannes 1884) report that the coloured matter in blood
is made of an animal substance combined with iron peroxide.
Friedrich Burdach (Leipzig 1776 - Königsberg
1847) names the cingulate gyrus and distinguishes lateral and
medial geniculate bodies.
1822 At the time of his death, René Just Haüy, elder
brother of Valentin, publishes his Traité
de cristallographie: suivi d'une application de cette science
à la détermination des espèces minérales et d'une nouvelle méthode
pour mettre les formes cristallines en projection,
where he establishes the rule for the cleavage planes in crystals.
Marie Ducrotay de Blainville (Arques 1777
- Paris 1850) pupil of Cuvier and Bichat publishes
des animaux. He states that the two principal characteristics
of life are
"composition" and "décomposition",
thereby starting to emphasize the role of metabolism in life.
He is also one of the promoters of embryological research.
1822-1826 Geoffroy Saint-Hilaire experimentally
produces abnormal development in chicks, providing an argument
1822-1831 Jean-Baptiste Bory de Saint-Vincent (Agen,
1778 - 1846) publishes the major Dictionnaire
classique d'histoire naturelle in 17 volumes (Rey et Gravier,
Baudouin frères, Paris), presenting natural history with a
materialistic and lamarckian point of view.
1822-1831 André Etienne Juste Pascal Joseph
baron de Férussac (Le Chartron, 1786 - Paris,
1836) creates the Bulletin général et universel
des annonces et des nouvelles scientifiques, a non academic
precursor of the Comptes-Rendus
de l'Académie des Sciences where he develops a visionary
panorama of human knowledge with prominent thinkers (up to 300
authors collaborated to this endeavour). Interestingly the Bulletin is
split into sections that have a very modern flavour (for example sciences
naturelles et géologie (section
2) go together as well as sciences agricoles et économiques (section
4)). Statistics, with the influence of Augustin
a central role in the Bulletin. 170 volumes were published
during the short history of the Bulletin, that had a
considerable influence, but has not yet been analysed in-depth.
The lack of support of this extraordinary entreprise both by
the French government and by the co-opted French academic world
marked the onset of the decline of the influence of France in
1823 Prévost and Dumas show
that urea is transported by the blood.
1823 Augustin Louis Cauchy (1789
- 1857) publishes his Résumé
des leçons données à l'Ecole royale polytechnique
sur le calcul infinitésimal, which triggers investigation
in the nature of real numbers.
Andrew Knight (Wormsley Grange 1759 -
Downton 1838) a most distinguished horticulturist and fruit
tree breeder, confirms reports of dominance, recessivity, and
segregation in peas, but does not detect regularities. However
all his papers mysteriously disappeared, which precludes further
Jean Pierre Flourens (Maureilhan 1794
- Montgeron 1867) opponent of Gall, states
in his Recherches
expérimentales sur les propriétés et les fonctions du système
nerveux dans les animaux vertébrés that cerebellum
regulates motor activity, divinding action into "action
propre" and "action
commune". In this work, Flourens details ablation
of nerve centers to study behavior.
1824 John Charles Caldwell (1772 –
1853) publishes his Elements of Phrenology developing Gall's
ideas (which remained fashionable for some time, in particular
with positivist philosophers).
Léonard Sadi Carnot (Paris 1796
- 1832), though still labouring within the
phlogiston (caloric) theory, advances the question of the nature
of heat and energy substantially in his remarkable paper, Réflexions
sur la puissance motrice du feu et sur les Machines propres
a développer cette Puissance, by considering
the question of the relation of quantity of heat to amount
of work done, and by introducing the conception of a machine
with a reversible cycle of operations.
1824 Henry Hill Hickman (1800
- 1830), a general practitioner, writes to Knight to describe
his experiments showing that carbon dioxide can be used to anesthetize
animals prior to surgery.
1824 Dutrochet further advances
the cell principle, already described by Robert Hooke,
and developed by Mirbel. He states that all
organic tissues are actually globular cells of exceedingly small
size, which appear to be united only by simple adhesive forces;
thus all tissues, all animal (and plant) organs, are actually
only a cellular tissue variously modified. This uniformity of
finer structure proves that organs actually differ among themselves
merely in the nature of the substances contained in the vesicular
cells of which they are composed. Dutrochet also
discovers and names the phenomenon of "osmose".
1824 Magendie provides a first evidence for
the role of the cerebellum in equilibration.
1824-1825 Prévost and Dumas repeat Spallanzani's
filtration experiments, thus confirming the necessity of spermatozoa
for fertilization, and describe cleavage in a frog egg.
1825 Jean-Baptiste Bouillaud (Garat, 1796
- Paris 1881) presents cases of loss of speech after frontal
lesions and argues that speech is localized in the frontal lobes
as Gall had suggested.
1825 Rolando describes the sulcus that separates
the precentral and postcentral gyri in the brain.
1825 Pierre Fidèle Bretonneau (1771-
Tours 1862) an epidemiologist, performs the first successful
1826 Antoine Becquerel (1788-1878) invents
the battery with two liquids.
Brongniart (1801 - 1876)
(son of Alexandre) first describes erratic movement of pollen
grains under the microscope in a paper presented at the Académie
1826 Johannes Peter Müller (Koblenz
1801 - Berlin 1858) publishes his theory of "specific nerve
energies", showing that sensory nerves could interpret an
impulse in but one way.
1827 Richard Bright (Bristol 1789 - 1858)
in his Reports of Medical Cases differentiates various
causes of dropsy.
Eugène Chevreul (Angers,
1786 - Paris, 1889) names hématosine the
red pigment found in blood.
1827 Magendie discovers the structure now known
as the foramen of Magendie, an opening from the fourth ventricle,
which is one in a system of four communicating cavities (ventricles)
within the brain.
1827 Horace Bénédict Alfred
Moquin-Tandon (Montpellier, 1804 - Paris, 1863)
publishes a description of several leech species in his Monographie
de la famille des Hirudinées. He later mistakenly
changes his mind and group them all under the common name Hirudo
1827 Fourier publishes his Remarques générales
sur les températures du globe terrestre et des espaces
planétaires, where he provides the first account
of the greenhouse effect that allows the Earth to have a mild
temperature. He is thus the precursor of the account of global
Amici (Modena 1786 - Firenze 1868) demonstrates
his first achromatic microscope lens system.
Ernst von Baer (Piep estate 1792 - Dorpat
1876) discovers the egg of mammals in the ovary, which he describes
in De ovi mammalium et hominis genesis. He regards the
sperm cells as "Entozoa," i.e., parasites, and names
Brown (Montrose 1773 - London 1858), while looking
for the molécules organiques postulated by Buffon,
describes the erratic movement of pollen particles under
the microscope. This process, since then known as the Brownian
motion had been observed by Ingenhousz fourty
years earlier. He also finds that Brongniart had
made the same discovery earlier, but does not name Ingenhousz,
and has his own paper published immediately in French and
1828 Publication of von Baer's Uber
Entwicklungsgeschichte der Tiere (On the Development of
Animals) which strongly opposes preformationism. Through this
book von Baer created modern embryology. He
rejects the Bonnet-Lamarckian theory of a uniform chain of
development in the animal kingdom and adopts Cuvier's
fixist ideas. However, he maintains that one must compare organs
at different stages of development in different animals. He
enunciates the law that the more dissimilar two animal forms
are, the further we have to go back in evolutionary history
to find an agreement, the common primitive form being the cell,
followed by the egg and the first embryonic stages (biogenetic
1800 - Göttingen 1882) synthesizes the first organic
compound from inorganic components, preparing urea by reacting
lead cyanate with ammonia.
1828 John Vaughan Thompson (Brooklyne
1779 - Sydney 1847) first collects and describes plankton. He
also correctly describes barnacles as crustaceans.
1829 Barthélemy Charles Joseph Dumortier (1797-1878)
publishes his Analyse des Plantes which is still at the
root of many plant classifications.
1829 Louis-René Lecanu (1800–1871) shows the presence of
cholesterol in an extract of hen egg yolk.
1829 Pierre Jean François Turpin (1775-1840),
hailed as possibly the finest French natural botanical artist
of his period, reports and illustrates his observations of cell
division in algae.
over construction of new microscopes. Following Charles
Chevalier (1771-1841) and his son Vincent
Chevalier (1804-1859) and
Amici, Joseph Jackson Lister (London
1786 - 1869) (father of Lord Joseph Lister who
discovered antiseptic techniques) makes lenses which corrected
for chromatic and spherical aberration.
1830 Clash between Cuvier and Geoffroy
Saint-Hilaire about the existence of a universal
map of organisms. At the time, the quarrel settles at the
advantage of Cuvier, but Geoffroy
Saint-Hilaire, who recognized segmentation in insects
and vertebrates, as well as inverted dorso-ventral segmentation
at the junction between thorax and abdomen of Crustacea was
right. One of his more infamous theories was that the segmented
external skeleton and jointed legs of arthropods such as
insects were equivalent to the internal vertebrae and ribs
of vertebrates; insects literally live inside their own vertebrae
and walk on their ribs. This prefigures the identification
of homeogenes, much later on. While some of Geoffroy
Saint-Hilaire comparisons seemed for a long time
somewhat far-fetched, his idea of an "unité de
plan" (amended into "théorie des
analogues") was insightful: "Pour ces sortes
de considérations il n'est plus d'animaux divers.
Un seul fait les domine, c'est comme un seul être qui
apparaît. Il est, il réside dans l'Animalité; être
abstrait, qui est tangible par nos sens sous des figures
diverses." Here we have clearly what would become
the concept of development program. And quite remarkably, Cuvier stated
that the features of the ink-fish, for example, have not
resulted from the development of other animals, nor have
in their own development produced any animal higher than
themselves. This was against Lamarck's transformist
view and demonstrated the limitations of the thought of Cuvier.
1830 Franz Julius
Ferdinand Meyen (Tilsit
1804 - Berlin 1840) reports in Phytotomie his observations
on algae, fungi and higher plants and concludes that each cell
forms an independent, isolated whole; the cell nourishes itself,
builds itself up, and elaborates raw nutrient materials, which
it takes up, into substances and structures of very different
1830 Robiquet and Antoine Boutron-Chalard (?-?)
isolate amygdalin discovered its hydrolytic splitting of by an
extract of defatted bitter almonds. The agent was named "emulsin" by Liebig and Wöhler in
1830 With his microscope, Amici investigates
the process of fertilization in plants and was able to trace
the growth of the pollen tube through the style to the micropyle
of the ovary.
1830 The German agronomist Karl Sprengel (1787-1859)
conduces pioneering research that could be considered the start
of agricultural chemistry, including disproving the humus theory
and formulating the Law of the Minimum (stating that the limiting
factor is that which controls growth, also known as Liebig's
1830 Berzelius coins the term "isomer" to
express the existence of chemicals with the same atomic composition
but different chemical properties.
1830 Robert Remak (Posen 1815 - Berlin 1865)
makes his first discovery, the "fibers of Remak", unmyelinated
nerve cell fibers. He later discovered and named the three layers
of early embryos. Working with animal cells, he also showed that
cells arise from preexisting cells by a process of binary fission.
Lyell (Kinnordy House 1797 - London 1875)'s Principles
of Geology creates stratigraphy, by advancing the
theory of uniformitarianism, i.e., the view that geological
formations are explainable in terms of forces and conditions
observable at present. They were influential on Darwin's
thoughts when he was aboard the HMS Beagle.
1830-1840 The use of leeches for bloodletting
peaks. The rationale for bloodletting had changed with the evolution
of new theories on the causes of diseases. Most physicians felt
that the depleting effect of bloodletting was "cooling" and
that it could relieve the congestion of inflamed capillaries
without diminishing resistance to disease.
Liebig (Darmstadt 1803 - München 1873)
develops techniques of quantitative analysis and applies
them to biological systems. His Law of the Minimum states
that growth yield is proportional to the amount of the most
limiting nutrient, whichever nutrient it may be. The idea
that vital activity could be explained in physicochemical
terms was an important one for investigators interested in
the nature of life.
1830-1842 Isidore Auguste Marie
François Xavier Comte (Montpellier
1798 - Paris 1857) writes the six large volumes of his Cours
de Philosophie positive. Trying to imitate Aristotle he
states that "positive" means "la même
chose que réel et utile", substituting for
the theological and metaphysical, which dominated during the
previous times. Three stages in human thoughts explain for
him the situation we witness today: the theological stage,
in which personal divine powers are thought to dominate and
explain all what happens in the Universe, the metaphysical,
when impersonal forces substituted to the personal divine forces,
and finally the positive stage, when the relevant question
is no longer
"why?" but sometimes "how?", and usually "what?".
He is most remembered for his classification of sciences into
six branches mathematics, astronomy, physics, chemistry, biology
and sociology (a word coined by Comte). Each
of these sciences is dependent on the preceding one, but has
characteristics of its own. Comte biological
speculation owe much to Blainville, rejecting
both vitalism and mechanism. Life is defined as the relation
between organism and environment, to be studied in its static
(potentially active) and dynamic (actually active) states. See
Makes Auguste Comte so Strange and so "Chinese"?
1831 Robert Brown publishes his observations
reporting the discovery and widespread occurrence of "areola" (which
he also names "nuclei") in cells. Brown distinguishes
angiosperms from gymnosperms in his classification of the higher
Hall (Basford 1790 - Brighton 1857) publishes A
Critical and Experimental Essay on the Circulation of the
Blood, where he distinguishes capillaries from arterioles
and venules on anatomical grounds. Using a Dollond achromatic
microscope, Hall describes for the first time the minute
arteriolo-venular communications that came to be known as"direct
channels or thoroughfare channels."
1831 Erhard Friedrich Leuchs (1800-1837) describes
the diastatic action of salivary ptyalin (amylase) on starch.
1831 Berzelius publishes his Traité
de Chimie. Several reprinting were later published, where
he quantifies the amount of iron peroxide found in hématosine
(hemoglobin), as half of a percent. Many various names for
hemoglobin begin to be used at the time: "zoohématine", "hématochroïne",
"cruorine", among others. Cruorin was to dominate for
several decades, with scarlet cruorin for "oxidised blood",
and purple cruorin for
voyage of the Beagle, with Charles Robert Darwin (Shrewsbury
1809 - Downe 1882) aboard as naturalist.
1832 The sedative chloral
hydrate is discovered.
1832 Robiquet isolates codeine from opium.
1832 Martin Heinrich Rathke (Danzig
1793 - Königsberg 1860) discovers the gill-slits in the
embryo of birds and mammals. His work in comparative embryology
is developed in Ûber die rückschreitende Metamorphose
der Tiere where he describes the disappearance of organs
(which remain present in lower species) during embryogenesis
of higher species.
1832 Although Schleiden and Schwann later
correctly articulated the cell theory, they were confused about
the formation of cells, thinking that they arose by processes
akin to precipitation or crystallization. The botanist Dumortier observing
the process of cell division in algae and in plant cells recognizes
that cells arose from preexisting cells by a process of binary
1832 Candolle publishes his Physiologie
1832 Dutrochet shows that gas exchange in
plants occurs via minute openings (stomata) on the surface of
leaves and the deep cavities with which they communicate. He
further demonstrates that only cells containing chlorophyll can
fix carbon and thus transform light energy into chemical energy.
In parallel, Dutrochet studies osmosis and suggests
it may be the cause of ascent and descent of sap in plants. Throughout
his work he endeavors to demonstrate that the vital phenomena
of life can be explained on the basis of physics and chemistry.
1833 Marshall Hall describes a function which
exists in the medulla independently of the brain: in this function
a stimulus produces a response independently of sensation or
volition. He names it "reflex."
1833 Jean Louis Rodolphe Agassiz (1807-1873)
with his Recherches sur les poissons fossiles, founds
1833 Geoffroy Saint-Hilaire publishes his
views that predate Darwin's vision: Influence
du monde ambiant pour modifier les formes animales. "The
external world is all-powerful in alteration of the form of
organized bodies.. . these [modifications] are inherited, and
they influence all the rest of the organization of the animal,
because if these modifications lead to injurious effects, the
animals which exhibit them perish and are replaced by others
of a somewhat different form, a form changed so as to be adapted
to the new environment." Darwin himself
cited both the elder Geoffroy Saint-Hilaire and
his son Isidore (who had continued to develop some of his father's
ideas) as persons who had anticipated his theory to a certain
1833 Jan Evangelista Purkinje (Purkyne)
(Libochovice 1787 - Prague 1869) discovers sweat glands. He later
discovered the neurons in the cortex of the cerebellum and the
conducting fibers in the heart which bear his name. He also studies
visual perception and devises the first system for classifying
fingerprints. Purkinje later invented the word protoplasm to
describe the embryonic material found in eggs.
1833 Johann Friedrich Meckel (Halle,
1781 - 1833), son and grandson
of known anatomists, develops descriptive and comparative
anatomy in the journal Archiv, and endeavours to write a thorough
treaty System der vergleichenden Anatomie, which he could
not complete before his death. This work is strongly influenced
by Lamarck's transformism. Interestingly he is at the root of
school later developped in Germany (and still often used today),
that ontogeny recapitulates phylogeny.
Joseph Dieudonné Boussingault (Paris, 1802 - 1887) professor
of analytical chemistry, recommends the use of iodized salt
to cure goiter.
Payen (Paris 1795-1871) and Jean-François
Persoz (Cortaillod 1805 - Paris 1868) further describe
and isolate diastase (amylase) in powder form from barley
malt, showing it to be heat labile. They postulate the central
importance of what would later be named "enzymes" in
Faraday (Newington 1791 - London 1867) enounces
his laws of electrolysis.
1834 Félix Dujardin (1801-1860) proposes
that single-cell animals should be classified in a group by themselves
that he called Rhizopoda (now named protozoans).
1834-1840 Johannes Müller in his Handbuch
der Physiologie des Menschen establishes a theory of specific
nerve energies, outlining a mechanistic theory of thinking.
1835 Berzelius demonstrates that the hydrolysis
of starch is catalyzed more efficiently by malt diastase than
by sulfuric acid and publishes the first general theory of chemical
1835 L. G. De Koninck and Jean-Servais
Belgium, 1813 – Bruxelles, Belgium, 1891)
isolate the bitter glycoside phlorizin, a phenylproponoid derivative,
from the bark of common apple trees (Pyrus malus). This
molecule is the subject of intense research as an inhibitor of
glucose recapture by the kidney (anti-diabetic effect).
1835 Robert Graves (1796-1853) describes exophthalmic
goitre ('Graves' disease'). On the European continent, however,
it is called 'Basedow's disease.'
1835 Rudolph Wagner (Bayreuth, 1805 - Göttingen,
1864) discovers a structure in oocyte germinal vesicles which
he names keimfleck
or macula germinativa. We now name it the nucleolus.
Bassi (Lodi 1773 - 1856) demonstrates in Del
mal del segno, calcinaccio o moscardino that a disease
of silkworms is caused by a fungus and shows that the disease
is contagious and can be transmitted naturally. This discovery
gave impetus to the germ theory of disease.
1835 Dujardin associates the "sarcode" (later
named protoplasm by von Mohl) of protozoa
with life processes.
1835 Charles Cagniard-Latour (Cagniard
de Latour) (1777-1859) finds that fermentation is
always accompanied by the rapid growth and multiplication of
plant-like organisms. Checking out his fermentations with a
good microscope, he asserts that these Torulæ are
minute organisms and that it is their activity that drives
Owen (Lancaster 1804 - 1892), later known for
his virulent campaign against Darwin, discovers Trichinella.
von Mohl (Stuttgart 1805 - Tübingen 1872)
carefully describes some details of mitosis in plants. He
recorded the appearance of the cell plate between daughter
cells. He remarks that cell division is everywhere easily
and plainly seen in terminal buds and root tips.
1836 Marc Dax (1770 - Montpellier 1837) describes
a group of patients who could not speak properly and, according
to his son Gustave, writes a memoir on the left hemisphere damage
effects on speech.
1836 The famed bloodletter François
Joseph Victor Broussais (Saint-Malo 1772 - Paris
1839) presents a series of twenty lectures on phrenology at
the University of Paris. Broussais promoted
the theory that all diseases result from inflammation caused
by an excessive build-up of blood, and that the body must be
weakened to be cured. He based his beliefs on his findings
of blood in the mucous membranes of the gastrointestinal tract
during postmortem examinations.
1836 Charles Giles Bridle Daubeny (1795-
Oxford 1867), who would later strongly support Darwin,
investigates the efficiency of different parts of the visible
spectrum in photosynthesis.
1836 Gabriel Gustav Valentin (1810
- 1883), pupil of Purkinje, identifies the nucleus
and the nucleolus in nerve cells. The nucleolus is the same structure
as that discovered by Wagner the year before
and later names it the nucleolus or kernkörperchen.
1836 Magendie demonstrates the need for dietetic
nitrogen in his Leçons sur les phénomènes physiques
de la vie.
1836 Robert Remak describes myelinated and
Schwann (Neuss 1810 - Köln 1882) reports the
action of pepsin and describes its properties. Putrefaction
and fermentation were then attributed to the action of micro-organisms.
Dickens (Landport 1812 - Gadshill 1870), famous
for his novels, describes obstructive sleep apnea.
Gottfried Ehrenberg (Delitzch 1795 - Berlin
1876) discovers the giant axons in the Crustacea.
1836 Purkinje and Samuel Moritz Pappenheim (Breslau
1811 - 1882) discover that another organ than
the stomach--namely, the pancreas--has a share in digestion,
Ladislaus Endlicher (Pressburg
1805 - Wien 1849) expert in the Chinese language, publishes his Genera
plantarum, which is the basis of all later plant classification.
Johannes Mulder (1802-1880) carries out the first systematic
studies of proteins. Mulder coins the word "protéine"
(in French) from πρωτειος, primarius,
as the main principle of all organic matter, in a Dutch journal
published in French, although most people credit Berzelius for
1837 Purkinje describes cerebellar cells (one
now bear his name); he identifies the neuron nucleus and dendritic
1837 Berzelius classifies fermentation as
a catalyzed reaction. He later identifies lactic acid as a product
of muscle activity.
1837 Stas moved to Paris, to profit from the scientific milieu.
As a collaborator of Dumas he performed a complete study of phlorizin,
splitting it into phloretin and glucose.
1837 Johannes Dzierzon (1811 - 1906) is supported
by Siebold who had studied the bee's sexual
apparatus. In his work he demonstrates that the female bee is
fertilized in the air. Dzierzon is the father
of modern rational bee-keeping.
1837 Henri Milne-Edwards (1800 - Paris 1885)
publishes his master piece: Histoire naturelle des crustacés.
1837 Heinrich Gustav Magnus (1802
- 1870) establishes experimentally again, after Lavoisier,
that the change of blood colour during respiration is due to
chemical changes occurring in the lungs.
1837 Dutrochet recognizes that chlorophyll
is necessary for photosynthesis.
1837 Dujardin demonstrates that the spermatozoa
are produced in the seminiferous tubules of the testis.
1837-1838 Theodor Schwann and Friedrich
Traugott Kützing (Ritteburg an der Unstrut, 1807 -
Nordhausen, 1893) in their turn, independently announce that
yeast is a living organism which is responsible for fermentation.
This starts the lengthy debate over whether fermentation is
a chemical or a vital process, which later on will culminate
in the debate between Louis
Pasteur and Claude Bernard.
1837-1840 Johannes Peter Müller (Coblenz
1801 - Bonn 1858) publishes his Handbuch der Physiologie des
Menschen für Vorlesungen, which was the authority on the subject in Germany
for several decades. Starting with a semi-mystical view inspired
by Goethe and Oken he investigates
in particular sense perception. His description is very similar
to that of Aristotle, placing emphasis on finality.
He believes in spontaneous generation and maintains the immutability
of both species and genera.
1837-1841 Avogadro publishes his treatise Fisica
dei corpi ponderabili, where he establishes, contrary to
theory of Dalton, that oxygen and nitrogen in
air are probably made of two atoms.
1838 Lignin is the second most abundant natural
polymer on earth first observed by Anselme Payen.
1838 Matthias Jakob Schleiden (Hamburg
1804 - Frankfurt-am-Main 1881) publishes his "Beiträge
zur Phytogenesis" in Müller's archives, an important
contribution to understanding the genesis of plant tissues. He
observes nucleoli but misinterprets their significance in considering
them as nuclei forming within nuclei (which he named "cytoblasts"). Theodor
Schwann applies the same erroneous theory of cell formation
to animal tissues but correctly emphasizes that "cells are
organisms and entire animals and plants aggregates of these organisms
arranged according to definite laws."
1838 Ehrenberg's Die
Infusionstierchen als vollkommene Organismen separates
what he later named bacteria from
other micro-organisms, seeing them as "complete organisms",
with all organs found in higher organisms.
1838 Robert Remak suggests that nerve fiber
and nerve cell are joined.
1838 Lecanu suggests that "hématosine" (hemoglobin)
combines albumin and an iron oxide as separate substances.
1838 Theodor Schwann describes the myelin-forming
cell in the peripheral nervous system ("Schwann Cell").
1839 Schwann proposes
the cell theory in his work entitled Mikroskopische Untersuchungen über
die Ubereinstimmung in der Struktur und dem Wachstum der Tiere
und Pflanzen. Here he takes as his starting point Schleiden's
cell-formation theory, and points out main differences between
animal and plant cells. He states that the common principle of
evolution is laid down for the most highly differentiated elementary
parts of the organisms, and this principle of evolution is the
cell-formation. This principle of the cell as the general unit
of life is immediately universally accepted.
1839 Boussingault quantitatively studies the
balance between the elementary constitution of the maintenance
ration of a cow and that of its excretions and milk production.
1839 Magendie discovers the anaphylactic shock.
1839 Chevreul publishes his treaty De la
Loi du contraste simuiltané des couleurs, where he describes
the perception of colours by the human eye. He divides
colors into two groups, primary colors (blue, yellow and red)
and secondary colors obtained by mixing primary colors together.
His theory was later summarized as "... je crois pouvoir
affirmer qu'il est possible d'assujettir les couleurs à une
nomenclature raisonnée en les rapportant à des types
classés d'après une méthode simple.... Une matière colorée
en rouge, en jaune, en bleu, en orangé, en vert et en violet
ne peut être modifiée que de quatre manières dans l'emploi
qu'on en fait en peinture ou en teinture...", thus
circles". This had
a considerable impact on the evolution of painting and on the
understanding of vision.
1839 Pierre François Verhulst (Bruxelles
1804 - 1849) develops the logistic model of population growth.
1839 Charles Chevalier (1804-1859) names "microtome"
a slicing instrument meant for microscope preparations he had
begun to construct in 1825.
1839 Francois Leuret (17971851)
and Louis Pierre Gratiolet (1815-1865) map the
folds and fissures of the cerebral cortex, and demarcate and
name the frontal, temporal, parietal and occipital lobes, in
particular the Rolandic sulcus for Luigi Rolando.
1839-1846 Purkinje proposes the term "protoplasm"
for living matter and, together with von Mohl,
establishes the protoplasm concept.
1840 Publication of Liebig's Tierchemie which
united the fields of chemistry and physiology. Here Liebig points
out that organic compounds in plants are synthesized from carbon
dioxide of the atmosphere while nitrogenous compounds are derived
from precursors in the soil. He proposes that fermentation is
chemical and not dependent on living microbes. This begins a
controversy over whether fermentation is a vital or a chemical
Sébastien César Dumont d'Urville (1790
- train accident near Versailles, 1842) on the Astrolabe
reaches the Antarctic continent at Terre
1840 Adolph Hannover (1814 -1894) uses chromic
acid to harden nervous tissue for microscopic preparations.
Bowman (Nantwich 1816 - Dorking 1892) describes
how the muscle is composed of fibrillae, surrounded by a
substance that he calls sarcolemma.
1840 Michael Sars (Bergen 1805 - Christiania?
1869) publishes an account of the complete development of two
species of jellyfish (published in French in the Annales des
sciences naturelles in 1841). This makes him famous throughout
Europe and is still of importance today.
1840 Jules Gabriel François Baillarger (1806-1890)
discusses the connections between white and gray matter of cerebral
six layers. Remak will find the same four years later.
1840-1841 Owen coins the word "dinosaurus" (terrible
reptile), which, becoming "dinosaure" was promised
to an immense success in the public.
Miller (1802-1856) investigates the Devonian
deposits of the Old Red Sandstone formation in Scotland,
one of the most important vertebrate-bearing sediments ever
discovered. Miller believed that the fossil
record confirmed the biblical account of creation. He publishes Footprints
of the Creator in 1847, and opposes evolution to his
death in 1856.
1841 Oken publishes his Allgemeine
Naturgeschichte für alle Stände. Apart from his half-mystical
beliefs, from quite another century, Oken tried
to accept papers from different camps with great impartiality,
he encouraged discussions and offered prizes for solutions,
with the object of promoting research. Oken also
to the initiative of another idea which has proved of immense
value in the future: he organized meetings of scientists for
the purpose of exchanging views and sharing ideas. In this
way Oken extended the peer system which was
only existing in Academia and in the Royal Societies of the
1841 Ehrenberg's opponent Félix
Dujardin (1801-1862) demonstrates that infusoria do
not have separate organs but consist of a membrane surrounding
a mass full of vacuoles and granules he called "sarcode",
term used in France, and later replaced by "protoplasm".
1841 Rudolf Albrecht von Kölliker (1817
- Würzburg 1905) traces the histogenesis of the spermatozoa
and proves that they are differentiated tissue cells.
1841 Marshall Hall coins the term "spinal
shock", Spinal shock refers to a transient loss of reflexes
below the level of a spinal cord injury. Spinal Shock is an injury
where the spinal column is subject to a forceful blow, but no
lesion occurs. The reaction of the nervous system is such that
it mimics a severed spine, and the signs and symptoms are identical.
1841 Following Bichat,Friedrich
Gustav Jakob Henle (Fürth 1809 - Göttingen
1885) publishes his Allgemeine Anatomie where he makes
the first description of many fine anatomic traits (in particular
of the intestine).
1841-1845 Dujardin in his "Histoire
Naturelle des Helminthes" describes the parasitic
1842 Bowman describes the histological structure
of the nephron.
1842 Publication of Schleiden's Grundzüge
des wissenschaftlichen Botanik, which created extraordinary
sensation, both favourable and unfavourable. Following Jacob
Friedrich Fries (Barby 1773 - Jena 1843),
professor of philosophy at Jena, Schleiden declares that the
aim of natural science is to relate all physical theories to
purely mathematical ground of explanation. He maintains, with Kant,
the contrast between subject and object, and develops a dualistic
approach which was, at the time in sharp opposition with that
of theologians (who were monists, following Hegel).
1842 Benedikt Stilling (1810 - 1879) is the
first to study the spinal cord in serial sections.
Robert von Mayer (Heilbronn
1814 - 1878) enunciates in the Annalen of Chemie the
first law of thermodynamics and its applicability to living
Ludwig Ferdinand von Helmholtz (Postdam 1821
- Berlin 1894) develops an important research (Über
die Erhaltung der Kraft published in 1847) in which the
law of the indestructibility of energy is stated (the first
law of thermodynamics). This is from this work that the theoretical
formula of this law has been adopted ever since. Helmoltz was
not aware of Mayer speculation, but the latter was bitterly
affected that no reference had been made to his work. However,
in contrast to Mayer, he had based his theory on experimental
facts rather than on theoretical speculation, and history of
natural sciences shows that theoretical conclusions are seldom
given the same significance as those derived from experiments.
The notion of proof remains central in science, especially
in biology, and it will be interesting to see when the theoretical
proof will reach the same level of confidence as
that of the experimental evidence.
1842 Johann Japetus Steenstrup (1813
- 1897) describes the alternation
of sexual and asexual generations in plants and animals.
1842 Liebig re-establishes in a convincing
way that the blood corpuscle that change colour upon respiration
are made of two separate components, one containing iron, that
is itself a compound associated to oxygen, since it is decomposed
by hydrogen sulfide in the same manner as iron oxides.
1842 Crawford Williamson Long (1815-1878)
uses ether for anaesthesia on man.
1842 Karl Wilhelm
von Nägeli (Kilchberg 1817 - München
1891), a pupil of Candolle, publishes his
work Zur Entwicklungsgeschichte des Pollens bei den Phanerogamen where he
describes accurately cell division.
1842-1850 Pierre Charles
Alexandre Louis (1787-1872) founds medical
statistics and clinical epidemiology. His work established
that blood letting was not beneficial for the patients.
Wendell Holmes (1809 - 1894) observes
the contagiousness of puerperal fever:The
Contagiousness of Puerperal Fever.
1843 Owen elaborates the concepts of homology
and analogy as "the same organ in different animals under
every variety of form and function." .
Braid (Earlsferry 1795 - Manchester 1860) coins
the term "hypnosis".
1843 Antoine Becquerel, who discovered piezoelectricity
summarizes the history of his invention of non polarisable battery
with two liquids (Note sur l'historique des piles à courant
constant). His battery, using copper sulfate or nitrate,
a neutral saline solution, a membrane and a copper blade was
invented in 1826, while Daniell invented a counterpart
only in 1836.
1843 Liebig speculates that organic acids
such as oxalic, tartaric, or malic are intermediates in the production
of carbohydrates by plants.
1843 Helmholtz separates a putrefying or a
fermenting liquid from one which was simply putrescible or fermentable
by a filter which allows the fluids to pass through, but stops
the passage of solids. The result is, that while the putrescible
or the fermentable liquids become impregnated with the results
of the putrescence or fermentation which is going on the other
side of the membrane, they neither putrefy (in the ordinary way)
nor ferment; nor were any of the organisms which abounded in
the fermenting or putrefying liquid generated in them.
1844 Darwin makes his first sketch of the
theory of natural selection.
1844 Remak provides an illustration of
the 6-layer cortex.
1844 Karl Wilhelm Ludwig (1819-1884)
shows that the Malpighian corpuscle of the kidney acts as a passive
filter and that the waste products in the filtrate are concentrated
as they passes through the tubules.
1844 Horace Wells (1815-1848) is the second
American to "discover" inhalation anesthesia (with
ether) for tooth extraction on his own person.
1844 John William Draper (Liverpool 1811 New
York 1882) shows that plants grown in solutions of sodium bicarbonate
can liberate oxygen in the light.
1845 Adolf Wilhelm Hermann Kolbe (1818-1884),
a pupil of Wöhler's, synthesizes acetic acid, previously
obtainable only as the result of vital activity, from nonorganic
materials. He later developed a method for the synthesis of salicylic
von Humboldt publishes Kosmos, a general
view of known facts about the Universe. He places emphasis
on the lifestyle of organisms (plants in particular) which
sets the stage for ecology.
1845 Mayer prints out by himself Die organische
Bewegung in ihrem Zusammenhange mit dem Stoffwechsel, where
he further elaborates his theory of conservation of energy.
This had been refused by the editors of scientific journals
despite the fact that this pamphlet applied the laws of conservation
of energy to relation between muscular energy and digestion
as well as to the assimilation of energy by plants (a process
that Mayer thought to be at the origin of life, and solar energy
to be its ultimate source). In consequence this demonstrated
that it was superfluous to hypothesize an extra energy source
for the origin of energy in living bodies. This was not well
accepted by the vitalist biologists of the time.
1845 Shortly after that James Prescott Joule (Salford
(Sale) 1818 - 1889) publishes
a theory based on years of experiments but giving a more
correct number to represent the heat equivalent. It is however
quite disputable that he could have really obtained accurately
the corresponding values.
1845 Remak describes the nerve fibers in the
sympathic system. He demonstrates also that nerve cell sprouting
is responsible for growth of nerve fibers during development
of the embryo.
1845 The Reverent Miles
Joseph Berkeley (1803-1889) demonstrates that
a mold is responsible for potato blight. He also made important
contributions to the classification of fungi.
1845 Luigi Porta (Pavia, 1800- 1875) publishes
an article on surgery of arteries and veins “Delle alterazioni
patologiche delle arterie per la legatura e la torsione, that
was to play an important role in cardio-vascular surgery.
1845 Kölliker extends his findings about
spermatozoa to the ovum, from which the organism is derived by
1845 Karl Theodor Ernst von Siebold (Würzburg
1804 - München 1885) defines the protozoa as we know them
today: "Die Tiere in welchen die verschiedenen Systeme
der Organe nicht scharf ausgeschieden sind, und deren unregalmässige
Forme und enifache Organization sich auf eine Zelle reduzieren
lassen"(animals whose organization is reducible to one
cell). Later, he discovers parthenogenesis in the honeybee.Siebold
resolves the dispute between Ehrenberg and Dujardin, showing,
in his Comparative Anatomy, that various forms previously
supposed to be Infusoria or distinct groups should be either
separated or grouped together into Protozoa, the Primary Animals, "Tiere,
in welchen die verschiedenen Systeme der Organe nicht scharf
ausgeshieden sind, und deren unregelmässige Form und einfache
Organisation sich auf eine Zelle reduzieren lassen."
1846 Siebold and Friedrich Hermann
Stannius (Hamburg 1808 - Rostock 1883) publish the Lehrbuch
der vergleichenden Anatomie der Wirbellosen Thiere where
Siebold takes the invertebrate section and Stannius that of
the vertebrates. By many aspects this work is similar to Owen's,
but much less known (and less speculative).
1846 Édouard Séguin (Clamecy,
1812 - New York, 1880) describes
the characteristic features of the children affected by the congenital
disease now known as Down's syndrome.
Degland (Armentières, 1787 - Lille, 1856)
publishes his Ornithologie Européenne, ou Catalogue
analytique et raisonné
des oiseaux observés en Europe extensively describing
European birds; he is at the origin of the establishment of
the Museum of Natural History at Lille.
Matteucci (Forli 1811 - Ardenza 1868) a former
foreign student at the Ecole Polytechnique in Paris invents
the kymograph, an instrument for recording variations in
pressure, as of the blood, or in tension, as of a muscle,
by means of a pen or stylus that marks a rotating drum. In
1842 he had discovered using a preparation known as the
'rheoscopic frog' that an electrical current accompanied
the contraction of all muscles, including cardiac muscle.
1846 William Thomas Green Morton (1819-1895)
and John Collins Warren (1778-1856) spread the practice of anesthesia
by demonstrating the use of ether anesthesia at the Massachusetts
1846 Pierre Joseph van Beneden (1809
- Louvain, 1894) establishes that a cysticercus is an incomplete
Boole (Lincoln 1815 - Cork 1864) in The Mathematical Analysis of Logic : being an essay towards a calculus of deductive reasoning establishes the formal laws of logics
which are at the core of computer sciences and classification.
1847 Concurrently with the work carried out
by Bilharz in Egypt, other Scientists and Physicians
were also becoming aware of this disease, particularly in Japan. Yoshinao
Fujii (1818 - 1895) a physician working in Numakuma
County, reports a disease he had noted in the district of Kawanami
and identifies the causative agent of
this disease, Schistosoma japonicum, four years before Bilharz
described his new trematode,
1847 The agriculture and horticulture society
of Utrecht gives is gold medal in an exhibition to a flower from
the Polygonaceae family, Fallopia japonica. One year later
this flower is sold in its catalogue. This is the beginning of
the invasion of Europe by this plant, and several of its cousins,
a plague that is, despite its highly restricted initial genetic
diversity, now out of control, occupying river banks in particular
and killing indigenous plants. Since this time the plant underwent
a doubling of its genome (it is now octoploid, with 88 chromosomes)
and produced a large variety of mutants that adapt to a large
set of biotopes.
1847 Rudolf Ludwig Karl Virchow (1821
- Berlin 1902) creates the Archiv für pathologische Anatomie
1847> Wilhelm Friedrich
Benedikt HofmeisterDie Entstehung des Embryo der Phanerogamen makes
sketches of microspore mother cells from Tradescantia which
show chromosomes in various stages of meiosis, but he fails
to grasp their significance.
1847 The same year Augustus DeMorgan (Madura
1806 - London 1871) publishes his Formal Logic in London.
Young Simpson (Bathgate 1811 - Edinburgh
1870) invents anesthesia with chloroform.
1847-1849 Arnold Adolphe Berthold (?-?)
demonstrates that transplant of a rooster's testis prevents
atrophy of the comb after castration. He then shows that the
testis produces a blood-borne substance conditioning sexual characteristics.
Philipp Semmelweis (1818-1865)
investigates the cause of puerperal fever and introduces disinfection
of hands in obstetrics; he shows that cleaning hands appropriately
can cut the number of deaths from puerperal fever by a factor
of one hundred. Unfortunately, he is opposed by high profile
professors of medicine protecting their privileges, and his method
is not implemented as it should have been, resulting in thousands
of premature deaths of women.
memoir of Louis
Pasteur (Dôle 1822 - Villeneuve l'Etang 1895)
at the Académie des Sciences on sulfur crystallisation: Mémoire
sur la relation qui peut exister entre la forme cristalline,
la composition chimique et le sens de la polarisation rotatoire.
1848 H Emanuel Merck (1794
- 1855) discovers papaverine in opium.
1848 Emil Heinrich Du
Bois-Reymond (Berlin 1818 - 1896) publishes
über tierische Elektrizität on animal electricity
(in particular that of electrical fish). This was the first part
of a work which was never completed. One of his major contribution
was the concept of "electrotonus"
a term coined to refer to potential changes produced by externally
applied current. He stated that von versciedenen Standpunkten
aus aufgenommene Abstractionhen der Dinge wie sie sind. Sie ergänzen
einander und sie setzen einander voraus
which allows him to conclude that the difference between the
organic and inorganic nature is of no importance whatsoever.
Gage (1823-1860) has his brain pierced by an
iron rod (the rod and his skull are preserved at Harvard
Medical School). He does not die, but his behaviour is drastically
altered. Alexander Luria, one century later in Soviet Union,
described similar phenomena in patients wounded during the
battle at Stalingrad.
1848 Siebold establishes Protozoa as the basic
phylum of the animal kingdom.
1849 Helmholtz measures the speed of frog
Victor Regnault (Aix la Chapelle 1810
- Paris 1878) and Jules Reiset (1818 - 1896)
publish extensive comparative studies of respiration and calorimetry.
Inspired by their work Jules Vernes in De la Terre à la
Lune, proposes that an apparatus made by Reiset and Regnault
produces oxygen in the projectile carrying the heros to our
Snow (1813-1858) discovers by epidemiological
studies the mode of cholera transmission. This is published
in On the Mode of Communication of Cholera.