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Great French Scientist's Contribution to the World of
Science
Angel
Miglani
(Year
9, OLSH College)
The
Bio-Riddle
I
was born on the 27th December 1822 in Dole. I found school
to be boring, and I was not exceptionally bright. It was
my father’s ambition for me to become a professor; however,
I only delighted in drawing and fishing. It was not until
secondary school that my talent in science lifted within
my soul and I won a scholarship to the most prestigious
French university. Studying crystallography and later
fermentation, I began to be known to the world. I saved
the world from small pox, anthrax, and cholera. Though
many ridiculed me for my discoveries, I believed in myself
and found a cure for rabies, as well. Being the discoverer
of microbes and inventing the application of weakened
microbes, I paved the way to the development of immunization.
I passed away at the age of 72 on the 28th September 1895
and was named the ‘Great French Scientist’ (Le grand Scientifique
français) . I also came up with the heating method
to kill microbes in food without destroying the food.
This method was named in my honour and called Pasteurization.
My first name begins with L. Who am I?
Louis
Pasteur
(1822-1895)
Louis
Pasteur’s Contributions to the World of Science
The
Great French Scientist, Louis Pasteur, devoted his life
to solving problems of science, agriculture, medicine
and the growing industry. His discoveries and cures have
saved countless lives and have created new wealth for
the world, not to mention the process of Pasteurization,
vaccines for chicken cholera, rabies, anthrax and ways
of preventing silkworm diseases. He was a very calm and
precise worker. Once he was sure of his discovery, he
would defend it strongly.
In
1847, at the age of 26, upon completion of his doctorate
degree, Louis began to study crystallography. He did his
first work on molecular asymmetry, bringing together the
principles of Crystallography, Chemistry and Optics. He
put together a fundamental law: “Asymmetry differentiates
the organic world from the mineral world”. This meant
that asymmetric molecules are always the product of life
forces, i.e. spontaneous generation. His work became the
basis of a new branch of science - Stereochemistry.
During
his research on Optics, he found that a polarized beam
of light that was passed through a pure solution made
up of natural organic nutrients had its polarisation rotate
either to the right or the left. Conversely, when such
a beam was passed through a solution of artificially synthesized
organic nutrients, there was no rotation of light’s polarisation.
This result was puzzling because the presence of bacteria
or other micro organisms again steered the beam of light’s
polarisation to the right or left. Hence, Pasteur concluded
that organic molecules are able to exist in two forms,
namely isomers (having the same molecular identity but
varying structurally) or stereoisomers, which refers to
having the same structure but being the absolute mirror
images of each other. These are also referred to as “Left
handed” and “Right handed” forms, respectively. When an
organic compound is synthesized, both forms are produced
in equal proportions, and they cancel out each other’s
optical effects. That explains why synthetic organic compounds
did not seem to rotate the polarisation of light in Pasteur’s
experiments.
In
1849, Pasteur moved to Lille, because he was appointed
as Professor of Chemistry. There he began his research
on Fermentation, which is defined as the chemical change
in organic substances brought about by enzymes. Louis
started off by examining the undesirable substances that
so often contaminated alcohol during fermentation. Over
time, he discovered that each sort of fermentation is
actually linked to the presence of specific micro-organisms.
He demonstrated that the fermentation that took place
to yield alcohol was due to yeast as well as the presence
of additional substances, such as bacteria. In addition,
Louis also showed that bacteria can be eliminated by heating
initial sugar solutions to high temperatures. Consequently,
he was able to solve the problem of wine and beer turning
sour, which had been a major economic concern in France.
Getting
more intrigued with each passing moment by the developments,
Pasteur extended these studies to other problems, such
as the curdling of milk. He proposed a similar solution
to counter the issue, which involved heating the milk
to a high temperature and pressure before bottling. This
method where milk is heated to 161 degrees Fahrenheit
for 15 seconds, followed by a rapid cooling to 50 degrees
Fahrenheit is currently known as Pasteurization. Pasteurization
is a widely applied method as it removes unwanted bacteria
from the milk, hence lengthening its shelf life.
In
1865, Pasteur had become the administrator and director
of scientific studies at the Ecole Normale. He began studying
silkworm diseases, which led to the discoveries of the
infectious agents that were responsible for crippling
the silk industry. He explained that these agents are
transmitted through a hereditary principle, where the
agent is passed on as the microorganisms reproduce.
Next
in line was saving the world from smallpox, chicken cholera,
rabies and anthrax. This great act was achieved based
on his proven hypothesis that tiny microbes that are invisible
to the naked eye, as well as to the microscopes of his
time, were responsible for these diseases. Upon establishing
the fact, Louis created vaccines by utilizing the actual
disease-causing agents and weakening them to a certain
degree such that they would not be able to cause the full-blown
diseases. These vaccines function by directing the immune
system; instigating the antibodies to go to war with the
antigens. In the midst of this process, the immune system
induces fever within the patient, as this will have an
adverse effect on the heat-sensitive microbes. However,
once all the antigens have been eradicated, the patient
undergoes remarkable recovery. This was the genesis of
immunization.
People
who did not suffer from these diseases were strongly encouraged
to get vaccinated. The vaccination exposed their bodies
to a weakened strain of foreign antigens, enabling the
immune system to develop pre-existing antibodies to the
disease-causing agents in preparation for future infections.
To date, vaccinations had saved millions of lives.
Quotes by Louis Pasteur -
“Do
not put forward anything you can not prove by experimentation.”
“Chance
favours only the prepared mind.”
“Let
me tell you the secret that has led me to the goal. My
only strength resides in my tenacity.”
“I am the most hesitating of men, the most fearful
of committing myself when I lack evidence. But on the
contrary, no consideration can keep me from defending
what I hold as true when I can rely on solid scientific
evidence.”
“Nothing is more agreeable to a man who has made science
his career than to increase the number of discoveries,
but his cup of joy is full when the result of his observations
is put to immediate practical use.”
“To believe one has discovered an important scientific
fact, to long to announce it, and yet to restrain oneself
for days, weeks, sometimes even years; to strive to disapprove
one’s own experiments; to publish one’s discovery only
after exhausting every alternative possibility -yes the
is a hard one. But when certainty is reached, the reward
is one of the keenest joys of which the human soul is
capable.”
“There is here no question of religion, philosophy, atheism,
materialism, or spiritualism. I might even add they do
not matter to me as a scientist. It is a question of fact;
when I took it up, I was as ready to be convinced by experiments
that spontaneous generation exists as I am now persuaded
that those who believe it are blindfolded.”
“Young
people, trust scientific method, whose first secrets we
yet scarcely know. Don’t be discouraged. Live in the serene
peace of laboratories and libraries. At the end of your
life, you will be able to say: I have done what I could.”
What Louis Pasteur Meant to the Scientific Community
He did strange and impossible experiments, the kind
that turn a crazy man into a genius when they come off.
He tried to change the chemistry of living things by putting
them between huge magnets. He devised weird clockworks
that swung plants back and forward, hoping so to change
the mysterious molecules that formed these plants into
mirror images of themselves…
-Paul
de Kruiff, from Microbe Hunters
“Pasteur was not a trained naturalist and he was working
alone, without a tradition behind him and without associates
with whom he could have shared his thoughts in moments
of doubts or astonishment. The many brief notes which
he left of his observations remind one of a child running
hither and thither in a wood, dazzled by the manifestations
of an unknown life which he half sees, half guesses, and
delighted to discover the diversity of the Creation.”
-Professor
Rene J. Dubos,
From Free Lance of Science
“He
had to fight ignorance, prejudice, the innate conservatism
of his eminent colleagues and of the medical establishment.
He fought this fight, with kindness, good humour, and
basic equanimity, which yet allowed the passion of his
‘exalted mind’ to drive him on and to inspire other …men
with some of his own enthusiasm.”
-H.I.,
from Louis Pasteur and Microbiology
Note:
This article was written by a Year 9 student from OLSH
College, and is an encouragement for high school students
to submit their work for publication.
References:
Beverly
Birch, Louis Pasteur, 1990, Exley Publications, Great
Britain.
http://www.louisville.edu/library/ekstrom/special/pasteur/cohn.html
http://www.lucidcafe.com/lucidcafe/library/95dec/pasteur.html
http://ambafrance-ca.org/HYPERLAB/PEOPLE/_pasteur.html
http://www.woodrow.org/teachers/chemistry/institutes/1992/Pasteur.html
http://www.accessexcellence.org/AB/BC/Louis_Pasteur.html
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