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LAMARCK, JEAN BAPTISTE PIERRE ANTOINE
DE MONET DE (b. Bazentin-le-Petit, Picardy,
France, 1 August 1744; d. Paris, France, 28 December
1829), botany, invertebrate zoology and paleontology,
evolution.
the four-element theory (earth, air, water, and fire)
was generally accepted in France. He continued to
believe in the four elements throughout his life
despite the work of Lavoisier and the chemical
revolution; for this reason his chemistry has often
been dismissed as worthless speculation. Yet Lamarck
took it very seriously, and it was an important part
of his ideas about nature and evolution.
Lamarck's first work in the field, Recherches sur
les causes des principaux faits physiques, was begun
in 1776. It was submitted to the Académie des Sciences
in 1780 and received an unfavorable report; it was
finally published in 1794, after the Academy had been
suppressed. Lamarck devoted two other full-length
studies to chemistry: Réfutation de la théorie
pneumatique
(1796) and Mémoires de physique et d'histoire
naturelle (1797). He also published two articles in
1799; they were reprinted at the end of his Hydrogéologie
(1802), which contained a long chapter
relating his chemical theories to his geological theories.
Although Lamarck's chemical views were ignored, he
continued to hold them; they appear with signs of
increasing paranoia in his major evolutionary works.
They play the most prominent role in Recherches sur
l'organisation des corps vivans (1802), the first full-length
exposition of his evolutionary theories.
In Lamarck's four-element theory, differences
between compounds depended on both the number
and proportion of the elements and the relative
strengths of the bonds between the elements in the
constituent molecules. Furthermore, each element
had a natural state in which it demonstrated its real
properties and several modified states in which it was
present in compounds. The most important of the
four elements in Lamarck's chemistry was fire, which
existed in three main states: a natural one and two
modified forms, which were fire in a state of expansion
(or caloric fire) and fixed fire. Using these three main
states and their many internal modifications, Lamarck
attempted to account for a great number of chemical
and physical phenomena such as sound, electricity,
magnetism, color, vaporization, liquefaction, and
calcination. Later, in his theory of evolution, he added
life as another phenomenon to be explained by
activity of fire. For Lamarck, fire not only explained
many processes, it also was a constituent principle of
compounds. He attempted to show how chemical
substances in their various states depended on differing
amounts of fixed fire. One temporary form of fixed
fire was phlogiston.
Lamarck believed that only living beings could
produce chemical compounds. Plants combined free
elements directly to produce a number of substances
of varying complexity. These in turn were elaborated
by the different animals eating the plants, the more
complex substances being produced by those animals
with the most highly organized physiological structure.
The process of compound formation involved
modification of the elements away from their natural
state and the more complex the substance, the greater
the modification. Once the forces of life were removed,
by death or the elimination of waste products, the
compounds began to disintegrate. The natural
tendency of all compounds, therefore, was to decompose
until the elements returned to their natural state,
in the process producing all known inorganic substances.
For the mineral kingdom there was a chain of
being with continous degradation from the most
complex to the simplest; this chain was composed of
individuals rather than species or types of minerals.
Lamarck's first statement of his theory of evolution in
1800 showed a similar thought pattern: degradation
and irrelevance of species.
In his chemistry, Lamarck showed a speculative
orientation and an emphasis on nature as a whole
with many interrelated parts and processes. His
distinction between the living and the nonliving was
crucial to his biology and his view of the mineralogical
chain of being was basic to his geology. His chemistry
was also later to be very important in his theory of
evolution. It was used to provide a materialistic
definition of life and to explain its maintenance,
appearance (both through reproduction and through
spontaneous generation), and the way in which living
organisms gradually evolve, including the emergence
of the higher mental faculties. Fire, as understood by
Lamarck, was the key element in all of these explanations.
Meteorology.
Lamarck's work in meteorology was
similar in many respects to that in chemistry. Although
one of his earliest scientific interests, he did not
publish anything until the late 1790's; he experienced
the same general lack of reception of his work in
chemistry. Meteorology was the first scientific area
in which Lamarck prepared a memoir and one which
was well received by the Academy. The manuscript
of this unpublished memoir (Muséum National
d'Histoire Naturelle, Paris, MS 755-1) shows that as
early as 1776, Lamarck was interested in the effects
of climate on living organisms. It is highly probable
that Lamarck's interest in chemistry resulted from his
concern with certain aspects of meteorology. His
general approach to science is also evident in this
early manuscript: his emphasis is on the general
principles, and he manifests disdain toward those
devoted solely to the collection of little facts. The
extent to which Lamarck saw his meteorology as part
of his whole view of nature is indicated later in his