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[Narrator:] And now let us go back about 300 years

to the London of Samuel Pepys.

In his famous diary, weread of a catastrophe

that was typical of that,and of the preceding, ages.

An epidemic of the plaguethat had been raging in Europe

took a fearful toll of lifein England's capital in 1665.

Hundreds fell ill every day.

Many of them diedin short order.

People were strickenon the streets.

Everyone fled fromthe victims for fear

of the dreaded disease.

But, by far, the most horrible element of the tragedy

was the mystery of its origin.

No one knew what, orwho, carried the plague.

The solution finally came by wayof this odd little contraption.

Does anyone know what this is?

No, it isn't a can opener.

[LAUGHTER]

It's the first microscope,It may look like a toy to us,

but its importance tohuman life is tremendous.

It's the connecting link betweenour science of modern medicine

and the distant past,when the world of germs

was unknown to man.

In 1683, not very longafter the London calamity,

Antonius van Leeuwenhoekground the lens

superior to any magnifyingglass of that day.

This Dutch naturalist setthis lens into a crude frame,

and thus constructedthis first microscope.

He examined drinking water.

Imagine the astonishmentof his friends

when he showed them tiny animalsswimming about in the fluid.

He even examined thecurve of the teeth

and found livingbeings too small

to be seen with the naked eye.

This was man's firstglimpse into the world

of germs with which hecomes in contact every day.

Van Leeuwenhoek hadopened this new world,

but he did not appreciate theimportance of his discovery.

In the following century,many scientists studied germs.

In 1762, Plenciz,the Viennese doctor,

contended thatmany diseases were

caused by living organismsinvisible to the human eye.

But no one wanted to hearabout the visions of a dreamer.

The medical men of thetime demanded facts,

and Plenciz had no proof.

Science was still waitingfor the great genius

of the microscope.

It took a hundredyears to find him,

but when he camehe revolutionized

the entire field of medicine.

Since 1860, all advancesin work with germs

have been based on thefundamental experiments

of Louis Pasteur.

This great Frenchmanestablished that germs did not

come to life by themselves.

By an ingenious test, heproved that germs would not

develop in a germ-free flaskunless they were carried there

by some outside agenciessuch as dust particles.

He used the microscopeto help the great wine

industry of France.

He recognized thefact that yeast cells

caused fermentationbut that very often

other organismsruined the beverages.

Pasteur experimentedand found he

could kill the harmfulorganisms with heat.

This was the first ofthe methods discovered

for killing germs.

It is possible todemonstrate this method

by placing an active culture ofbacteria under the microscope,

applying heat, and thenobserving the germs forming

in clusters as they die.

The use of heat to killgerms, as in pasteurization,

is today vital in safeguarding many of our foods,

particularly milk.

Disease germs, ifpresent, are eliminated

by passing the milkover heated coils,

so that when itis finally served

it shall contain nothingbut the nourishing qualities

that ensure good health.

In England, Dr. Lister, whohad been carefully studying

the work of Pasteur,conceived the idea

that germs might be responsiblefor the pus infection

of wounds.

In those days, asurgical operation

was a gamble with deathfrom blood poisoning.

Lister found thathe could avert this

by killing the germsin and around the womb.

He sprayed everythingwith carbolic acid

and bathed his instruments withthe same chemical solution.

He destroyed thegerms with chemicals,

just as Pasteurhad done with heat.

This was the second ofthe methods discovered

for killing germs.

The modern antiseptic andaseptic methods of surgery

are the outgrowth ofLister's early experiments.

Throughout France,sheep were dying

in large numbers of thedisease known as anthrax.

The great Pasteurfound that germs were

responsible for this scourge.

He prepared a vaccinethat enabled farmers

to protect their sheepand cattle from anthrax.

Thus, Pasteur discoveredthe third method

of combating germs, that isby strengthening the defense

forces of the body through theuse of vaccines and antitoxins.

It was by means ofthis third method

that he achieved the crowningglory of his brilliant career--

the successful fight againstrabies, or hydrophobia.

This humble chemistbecame the founder

of modern scientific medicineand one of the greatest

benefactors of the human race.

Pasteur's successfulexperiment fixed the position

of the microscope in scientificmedical investigation.

In the next 50years, more progress

was made in medicine thanin the previous 2,000 years.

It is hard to believethat, as late as 1832,

New York was at thealmost complete mercy

of many infectious diseases,such as cholera, diptheria,

and smallpox, althoughvaccination, then as now,

would have wiped out this last disease.

The New York Postof June 16, 1832

carried the story of anepidemic of Asiatic cholera

that had broken out in Canada.

It was feared that the diseasewould reach New York shortly

and that nothing couldbe done to stop it.

The epidemic did arrive andlater spread its fearful hand

over Europe, as well.

Not until 1883 didRobert Koch discover

the germ that caused cholera.

In the preceding year,Koch had found the germ

responsible for tuberculosis.

Later, the typhoidgerm was revealed

by two German scientists,Dr. Eberth and Dr. Gaffky.

And, in 1883, Dr. Klebsdiscovered the germ

that caused diphtheria.

But the real fight againstthe merciless diphtheria germ

was yet to be won.

On Christmas Eve, 1891, inthe Von Bergmann Hospital

in Berlin, a little girlwas fighting for her life

against this murderous disease.

One ray of hope lay inthe skill and genius

of Dr. Von Behring, aformer military surgeon who

had been making remarkableexperiments under Dr. Koch.

He had successfully cureddiphtheria in animals

by means of an antitoxin.

With the courage and daringof a great scientist,

he was now ready totake the eventful step

from the laboratoryto the sick bed.

He brought his wonderfulserum to the aid

of the stricken child.

In a minute, the painlessinjection had been completed.

The contribution vonBehring made to humanity

that Christmas Eve willremain an everlasting symbol

of his goodwill to men.

Once again, manhad conquered germs

by the third methodof combat, that

of helping the body in its fightagainst the agents of disease.

Von Behring'sachievement was great,

but he saw that it would befar more wonderful to prevent

the disease than to cure it.

This ideal hasnow been achieved,

and today we havetoxin antitoxin,

or toxoid, with which we areable to protect our children

against diphtheria.

Not all germs disclosedby the modern microscope

are injurious to man.

Some, in fact, areessential to his very life.

Many live in the soiland make it possible

for us to grow the fruit,grains, and other plant

products so necessary forthe existence of animals

and mankind.

But the injuriousgerms, and indeed,

the causes of thosediseases not due to germs,

must be discovered, controlled,and, if possible, destroyed.

The causes of manydiseases have come

to be known inthe last 50 years,

but there are others thatstill elude the searching eye

of modern science.

The cause and cure for infantileparalysis, rheumatic fever,

and cancer are among thebaffling mysteries yet

to be solved.

But there is everyreason to believe

that the scientists will besuccessful in the future.

Year after year, theystruggle unrelentingly,

sometimes sacrificingtheir own lives

to find new ways ofcontrolling disease.

They are fighting the battleof man against microbe

so that we, unhampered bythe scourge of sickness,

may achieve fullnessof life and happiness.

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