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These pages represent a biased
choice of dates relevant to biology, obtained by compiling
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does not use Wikipedia which, by construction, relies on
a process akin to a vote, and changes over time in order
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knowledge rather than accurate knowledge. Care has
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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 of organs.
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.
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
uses the term "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
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
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
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
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 anatomicarum explicatio.
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
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,
a "tonus" 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.
1802 Pierre 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 membranous tissue.
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
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-d’Hébertot 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
Dalton (Manchester 1766 -1844) enunciates his
atomic theory (hence the mass unit created after his name,
the Dalton, mass of the hydrogen atom).
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 are explored.
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)
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
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
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
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
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).
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 Mollusca.
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
Rolando (Torino, 1773 - 1831) works on the
brain of birds and uses galvanic current to stimulate the
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.
1810 Christian 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 of negative
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
Louis Gay-Lussac (Saint Léonard de Noblat 1778 -
Paris 1850) deduces the equation for alcoholic
--> 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
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
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
his Théorie 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 origin.
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.
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 animal, distribué 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
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
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 Protozoa.
Jacques Thénard (Louptière 1777 - Paris 1857)
publishes his Traité
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
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
1819 Arthur Jacob (1790 - 1874) describes the
layer of the retina containing the rods and cones (in the
1819 Proust identifies a molecule he names acide
caséeux, and that we know today as the amino acid leucine.
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
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.
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 Nazi
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 his Traité 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 against preformation.
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
François d'Audebard, 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 Cournot plays 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 science.
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
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 investigation.
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
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
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
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 des
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
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 medicinalis.
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
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 them spermatozoa.
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
Wöhler (Eschersheim 1800 - Göttingen 1882)
synthesizes the first organic compound from inorganic
components, preparing urea by reacting lead cyanate with
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.
1830 Dispute over construction of new microscopes.
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
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.
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 types.
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
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 law).
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
1830-1840 Justus von 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.
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 also What 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 plants.
1831 Marshall 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
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 "deoxidised blood".
of researches; The voyage of the Beagle,
Robert Darwin (Shrewsbury 1809 - Downe 1882)
aboard as naturalist.
1832 The sedative chloral hydrate is
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 fission.
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."
Louis Rodolphe Agassiz
(Môtier-en-Vuly, Suisse 1807- Cambridge, Mass, USA 1873)
with his Recherches sur les poissons fossiles,
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 degree.
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 the "recapitulationist" school later
developped in Germany (and still often used today), that
ontogeny recapitulates phylogeny.
Joseph Dieudonné Boussingault (Paris, 1802 -
Paris 1887) professor of analytical chemistry, recommends
the use of iodized salt to cure goiter.
1833-1834 Anselme 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 < p="" <="" biology.="" in=""> <>
1834 Michael 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
1834-1840 Johannes Müller in his Handbuch der
Physiologie des Menschen establishes a theory of
specific nerve energies, outlining a mechanistic theory of
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 catalysis.
1835 L. G. De Koninck and Jean-Servais
Stas (Louvain, 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
1835 Dujardin associates the < 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
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.
1836 Christian Gottfried Ehrenberg
(Delitzch 1795 - Berlin 1876) discovers the giant axons in
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
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 this invention.
1837 Purkinje describes cerebellar cells (one
now bear his name); he identifies the neuron nucleus and
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 (Bruges 1800 - Paris
1885) publishes his master piece: Histoire naturelle
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.
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
1837-1841 Avogadro publishes his treatise Fisica
dei corpi ponderabili, where he establishes,
contrary to the "indivisible" theory of Dalton,
that oxygen and nitrogen in air are probably made of two
1838 Lignin is the second most abundant natural
polymer on earth first observed by Anselme Payen.
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
1838 Theodor Schwann describes the myelin-forming
cell in the peripheral nervous system ("Schwann Cell").
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
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
defining "chromatic circles". This had a considerable
impact on the evolution of painting and on the
understanding of vision.
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 (1797–1851) 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
Sébastien César Dumont d'Urville (1790 -
train accident near Versailles, 1842) on the Astrolabe
reaches the Antarctic continent at Terre Adélie.
1840 Adolph Hannover (1814 -1894) uses chromic
acid to harden nervous tissue for microscopic
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 cortex, revealing
six layers. Remak will find the same four
1840-1841 Owen coins the word "dinosaurus"
(terrible reptile), which, becoming "dinosaure" was
promised to an immense success in the public.
1841 Hugh 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 believes 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 time.
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
1841 Rudolf Albrecht von Kölliker (1817
- Würzburg 1905) traces the histogenesis of the
spermatozoa and proves that they are differentiated tissue
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
Anatomie where he makes the first
description of many fine anatomic traits (in particular of
1841-1845 Dujardin in his "Histoire Naturelle
des Helminthes" describes the parasitic protozoa.
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.
1842 Julius Robert von Mayer (Heilbronn
1814 - 1878) enunciates in the Annalen of Chemie
the first law of thermodynamics and its applicability to
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
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.
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.
Charles Alexandre Louis (1787-1872) founds
medical statistics and clinical epidemiology. His work
established that blood letting was not beneficial for the
Wendell Holmes (1809 - 1894) observes the
contagiousness of puerperal fever:The Contagiousness of
1843 Owen elaborates the concepts of homology
and analogy as "the same organ in different animals under
every variety of form and function." .
1843 James Braid (Earlsferry 1795 -
Manchester 1860) coins the term "hypnosis".
1843 Antoine-Cesar Becquerel (1788-1878), 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
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
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
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 -
Leipzig 1884), a pupil of Wöhler, 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 acid.
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
1845 Kölliker extends his findings about
spermatozoa to the ovum, from which the organism is
derived by cell division.
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
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
1846 Édouard Séguin (Clamecy, 1812 - New York,
1880) describes the characteristic features of the
children affected by the congenital disease now known as
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 < p="" <="" muscle.="" cardiac="" including=""
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 General Hospital.
1846 Pierre Joseph van Beneden (1809 -
Louvain, 1894) establishes that a cysticercus is an
1847 George 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
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 und Physiologie.
1847 Wilhelm Friedrich Benedikt Hofmeister
(Leipzig 1824 - Lindenau 1877) in Die 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
1847 James Young Simpson (Bathgate 1811 -
Edinburgh 1870) invents anesthesia with chloroform.
1847-1849 Arnold Adolphe Berthold (1803 -
1861) 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.
Ignaz 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 Heinrich Emanuel Merck (1794 -
1855) discovers papaverine in opium.
Heinrich Du Bois-Reymond (Berlin 1818 -
1896) publishes his Untersuchungen 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.
1848 Phineas 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 nerve
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 satellite.
1849 John Snow
(1813-1858) discovers by epidemiological studies the mode
of cholera transmission. This is published in On the
Mode of Communication of Cholera.