rearrangement See DEGENERATE REARRANGEMENT;
MOLECULAR REARRANGEMENT; SIGMATROPIC REAR-
RANGEMENT.
rearrangement stage The ELEMENTARY REACTIONor
REACTION STAGE(of a MOLECULAR REARRANGEMENT)
in which there is both making and breaking of bonds
between atoms common to a reactant and a reaction
product or a reaction INTERMEDIATE. If the rearrange-
ment stage consists of a single elementary reaction, this
is a “rearrangement step.”
Réaumur, René-Antoine Ferchault de(1683–1757)
FrenchPhilosopher, naturalist René-Antoine Réau-
mur was born in La Rochelle, France, in 1683. After
studying mathematics in Bourges, he moved to Paris in
1703 at age 20 under the care of a relative. Like most
scientists of the time, he made contributions in a num-
ber of areas, including meteorology. His work in math-
ematics allowed him entrance to the Academy of
Sciences in 1708. Two years later, he was put in charge
of compiling a description of the industrial and natural
resources in France, and as a result developed a broad-
based view of the sciences. It also inspired him into the
annals of weather and climate with the invention of a
thermometer and temperature scale.
In 1713 he made spun glass fibers, today the
building blocks of Ethernet networking and fiber
optics, which are still made of the same material. A
few years later, in 1719, after observing wasps build-
ing nests, he suggested that paper could be made from
wood in response to a critical shortage of papermak-
ing materials (rags) at the time. He was also impressed
by the geometrical perfection of the beehive’s hexago-
nal cells and proposed that they be used as a unit of
measurement.
He turned his interests from steel to temperature,
and in 1730 he presented to the Paris Academy his
study “A Guide for the Production of Thermometers
with Comparable Scales.” He wanted to improve the
reliability of thermometers based on the work of Guil-
laume Amontons, though he appears not to be familiar
with DANIELGABRIELFAHRENHEIT’s earlier work.
His thermometer of 1731 used a mixture of alco-
hol (wine) and water instead of mercury, perhaps creat-
ing the first alcohol thermometer, and it was calibrated
with a scale he created called the Réaumur scale. This
scale had 0°for freezing and 80°for boiling points of
water. The scale is no longer used today; however, at
the time most of Europe, with the exception of the
British Isles and Scandinavia, adopted his thermometer
and scale.
Unfortunately, errors in the way he fixed his points
were criticized by many in the scientific community at
the time, and even with modifications in the scale,
instrument makers favored mercury-based thermome-
ters. Réaumur’s scale, however, lasted over a century,
and in some places well into the late 20th century.
Between 1734 and 1742, Réaumur wrote six vol-
umes of Mémoires pour servir à l’histoire des insectes
(Memoirs serving as a natural history of insects).
Although unfinished, this work was an important con-
tribution to entomology. He also noticed that crayfish
have the ability to regenerate lost limbs and demon-
strated that corals were animals, not plants. In 1735 he
introduced the concept of growing degree-days, later
known as Réaumur’s thermal constant of phenology.
This idea led to the heat-unit system used today to
study plant-temperature relationships.
In 1737 he became an honorary member of the
Russian Academy of Sciences, and the following year
he became a fellow of the Royal Society.
After studying the chemical composition of Chi-
nese porcelain in 1740, he formulated his own Réau-
mur porcelain. In 1750, while investigating the animal
world, he designed an egg incubator. Two years later, in
1752, he discovered that digestion is a chemical process
by isolating gastric juice and studied its role in food
digestion by observing hawks and dogs.
He died in La Bermondiere on October 18, 1757,
and bequeathed to the Academy of Science his cabinet
of natural history with his collections of minerals and
plants.receptor A molecule or a polymeric structure in or
on a cell that specifically recognizes and binds a com-
pound acting as a molecular messenger (neurotransmit-
ter, HORMONE, lymphokine, lectin, DRUG, etc.).receptor mapping The technique used to describe
the geometric or electronic features of a binding site
when insufficient structural data for this RECEPTORor234 rearrangement