Louis Pasteur
PASTEUR, Louis (1822-95). The French chemist Louis Pasteur devoted his
life to
solving practical problems of industry, agriculture, and medicine.
His
discoveries have saved countless lives and created new wealth for the
world.
Among his discoveries are the pasteurization process and ways of
preventing
silkworm diseases, anthrax, chicken cholera, and rabies. *BR*
Pasteur sought no
profits from his discoveries, and he supported his family
on his professor's
salary or on a modest government allowance. In the
laboratory he was a calm and
exact worker; but once sure of his findings, he
vigorously defended them.
Pasteur was an ardent patriot, zealous in his
ambition to make France great
through science. *BR* *BR* *BR* Scholar and
Scientist*BR* Louis Pasteur was born
on Dec. 27, 1822, in Dôle, France. His
father was a tanner. In 1827 the family
moved to nearby Arbois, where Louis
went to school. He was a hard-working pupil
but not an especially brilliant
one. *BR* When he was 17 he received a degree of
bachelor of letters at the
Collège Royal de Besançon. For the next three years
he tutored younger
students and prepared for the École Normale Supérieure, a
noted
teacher-training college in Paris. As part of his studies he investigated
the
crystallographic, chemical, and optical properties of various forms
of
tartaric acid. His work laid the foundations for later study of the
geometry of
chemical bonds. Pasteur's investigations soon brought him
recognition and also
an appointment as assistant to a professor of chemistry.
*BR* *BR* Pasteur
received a doctor of science degree in 1847 and was
appointed professor of
chemistry at the University of Strasbourg. Here he met
Marie Laurent, daughter
of the rector of the university. They were married in
1849. Pasteur's wife
shared his love for science. They had five children;
three died in childhood.
*BR* *BR* *BR* *BR* Research in Fermentation and
Souring*BR* In 1854 Pasteur
became professor of chemistry and dean of the
school of science (Faculté des
Sciences) at the University of Lille.
Hearing of Pasteur's ability, a local
distiller came to him for help in
controlling the process of making alcohol by
fermenting beet sugar. Pasteur
saw that fermentation was not a simple chemical
reaction but took place only
in the presence of living organisms. He learned
that fermentation,
putrefaction, infection, and souring are caused by germs, or
microbes. *BR*
Pasteur published his first paper on the formation of lactic acid
and its
function in souring milk in 1857. Further studies developed the
valuable
technique of pasteurization (see Dairy Industry). The same year he
was appointed
manager and director of scientific studies at his old school,
the École Normale
Supérieure. During the next several years he extended
his studies into the germ
theory. He spent much time proving to doubting
scientists that germs do not
originate spontaneously in matter but enter from
the outside. *BR* *BR* *BR*
Developing Cures for Agricultural
Diseases*BR* In 1865 Pasteur was asked to help
the French silk industry,
which was near ruin as a result of a mysterious
disease that attacked the
silkworms. After intensive research, he discovered
that two diseases were
involved, both caused by bacteria on the mulberry leaves
that provided food
for the worms. The diseases were transmitted through the eggs
to the next
generation of worms. Pasteur showed the silkworm breeders how to
identify
healthy eggs under the microscope, how to destroy diseased eggs and
worms,
and how to prevent formation of disease bacteria on the mulberry leaves.
*BR*
At 45 Pasteur was struck by paralysis. For a time recovery was uncertain,
and
he was confined to bed for months. The attack left its mark; for the rest
of
his life, one foot dragged a little as he walked. *BR* *BR* In 1877
Pasteur
began to seek a cure for anthrax, a disease that killed cattle,
sheep, and other
farm animals. He drew on research he was conducting on
another animal disease,
chicken cholera. When he inoculated healthy chickens
with weakened cultures of
the cholera microbes, the chickens suffered only a
mild sickness and were
thereafter immune to the disease. Pasteur successfully
applied this technique of
immunization to the prevention of anthrax. *BR*
*BR* Many scientists challenged
Pasteur's anthrax prevention claims, and
Pasteur agreed to a dramatic test.
Forty-eight sheep and a few cows and
goats were gathered in a pasture near the
town of Melun. Half the animals
were first immunized with cultures of weakened
anthrax microbes; then all
were injected with strong cultures. *BR* *BR* Within
a few days, the
untreated animals were dead; but the immunized animals showed no
effect of
the disease. The test verified Pasteur's results beyond all doubt.
Later
he proposed that all inoculation cultures be called vaccines and
the
inoculating technique, vaccination (see Vaccines). *BR* *BR* *BR* *BR*
Treatment
for Rabies*BR* Human beings contract rabies (or hydrophobia) when
they are
bitten by a dog or another animal that is suffering from the
disease. Rabies
slowly destroys the central nervous system by attacking the
spinal cord. *BR*
Pasteur reasoned that it might be possible to immunize
people after they had
been bitten but before destruction of the spinal cord
began. He took spinal cord
tissues of animals that had died of rabies and
dried them for varying periods of
time. He then made inoculations of the
tissues and injected them into another
stricken animal. The first inoculation
was from the driest, weakest culture, and
each successive inoculation was
stronger. After repeated failures, he finally
succeeded in halting the
development of rabies in an infected dog. The treatment
required 14
inoculations. *BR* *BR* Pasteur hesitated to try the remedy on
humans. The
decision was forced on him in 1885 when the mother of 9-year-old
Joseph
Meister begged Pasteur to save her son. The boy had been bitten 14 times
by a
rabid dog. Pasteur treated the child. The wounds healed and no trace
of
rabies appeared. Thus Joseph became the first person saved by
Pasteur's
treatment. *BR* *BR* Pasteur had won many honors for his previous
discoveries;
now the world united to do him special homage. Thousands of
people contributed
funds to establish a great laboratory, the Pasteur
Institute, where scientists
conduct research on various diseases. Pasteur
died near St-Cloud on Sept.
28,
1895.