From the practical point of view, the susceptibility to infection of the guinea pig proved to be the most useful step forward. Today, all laboratories use this animal for preserving the virus.

The fact that I was fortunate enough to escape contagion, in spite of frequent, sometimes daily contacts with the disease, was because I soon guessed how it spread.

The discovery that I soon made that the guinea pig was also susceptible to infection made it possible for me, from the third year on, to preserve the virus on this animal.

From the practical point of view, the susceptibility to infection of the guinea pig proved to be the most useful step forward. Today, all laboratories use this animal for preserving the virus.

I was less successful in my attempts to effect preventive vaccination against typhus by using the virus and in trying to produce large quantities of serum using large animals.

My first attempts to transmit typhus to laboratory animals, including the smaller species of monkeys, had failed, as had those of my predecessors, for reasons which I can easily supply today.

I finally demonstrated that typhus infection is not hereditary in the louse.

Just as the only reservoir for the typhus virus in nature is provided by man, so the only vector of infection is the louse. The bite of the louse is not virulent immediately after the infecting meal. It becomes so only towards the 7th day following infection.

Even if it had not been possible to reproduce the disease in animals and consequently to verify the hypothesis, this simple observation would have been sufficient to demonstrate the way in which the disease was propagated.

Most of the doctors in the Tunisian administration, especially those in country districts, contracted typhus and approximately one third of them died of it.

Of all the problems which were open to me for study, typhus was the most urgent and the most unexplored. We knew nothing of the way in which contagion spread.

I demonstrated the characteristics of experimental fever. It appears after an incubation period which is never less than five days. It follows the same pattern as natural fever in man, but is of shorter duration and less pronounced.

At the time when I was conducting my research there was no known method for taking the guinea pig's temperature. I demonstrated a technique which is now widely used.

It did not seem likely that I was destined to undertake research on typhus.

Socialism proposes no adequate substitute for the motive of enlightened selfishness that today is at the basis of all human labor and effort, enterprise and new activity.

I am tomorrow, or some future day, what I establish today. I am today what I established yesterday or some previous day.

If I had to come up with something that just came to me, I think growing up in a small town, I want knowledge. I still think today, knowledge is one of the keys.

There's more than a few remnants left in German welfare policy today. Many Germans eagerly condemn Hitler's fascism but won't examine the other reasons why the Third Reich succeeded for a season.

Compared to today's salaries, our cut was minuscule but it was very good for the time.

The NFL today has bigger, stronger, bodies than ever, moving faster than ever, hitting a stationary object harder than ever before - so the physics of the hit have changed.

The President of today is just the postage stamp of tomorrow.

I'm so happy because today I found my friends - they're in my head.

I don't know where the stock market is going, but I will say this, that if it continues higher, this will do more to stimulate the economy than anything we've been talking about today or anything anybody else was talking about.

I'm not up on today's television for children, because it's mostly cartoons that don't seem to interest me.

We aim in the domain of politics at republicanism; in the domain of economics at socialism; in the domain of what is today called religion, at atheism.

Today's interpretations of religion are often backward and contradict the needs of civilization.

The most profound, tangible influence in my life has been my wife, Monique. I don't know that I would even be alive were it not for her, and I certainly would not be the person that I am today.

Were you to read the British press today, you would learn that the British Empire never forgets its defeats.

As patients and consumers, we are better informed today about our health care than any previous generation.

A couple of guys won Academy Awards for the things that I turned down. Today, after coming to terms with everything, after being in therapy for a long time-there are areas where I will compromise.

I know the history of the record business so well because I followed Billie Holiday into the record studios. It was so primitive compared to the sophisticated business today.

Especially today as we fight the war on terror - against an enemy that represents hatred, extremism and stands behind no flag - we need to remember the sacrifices that have gone into protecting our flag.

The investor of today does not profit from yesterday's growth.

The Lord gave us Ten Commandments, but the bill before the House today gives us 39.

The growth of technology is such that it is not possible today for a nuclear physicist to switch into medical physics without training. The field is now much more technical. More training is needed to do the job.

One needs a Seer's Vision and an Angel's voice to be of any avail. I do not know of any Indian man or woman today who has those gifts in their most complete measure.

Well, I go to the theater today, and its curtain - there is no curtain in this play; the lights go down and go up - and we start. And I live this character for two hours. There are only two of us in the play. And It's a complete experience.

We are demonstrating for services for all the people and not just services for money. It's very important that this message goes to the European Parliament today.

The Clinton White House today said they would start to give national security and intelligence briefings to George Bush. I don't know how well this is working out. Today after the first one Bush said, 'I've got one question: What color is the red phone?'

People with fertility problems are not alone. It is a very very common problem for couples today. I've seen statistics that are just staggering.

Yesterday I was a dog. Today I'm a dog. Tomorrow I'll probably still be a dog. Sigh! There's so little hope for advancement.

There are seven winners of the Monaco Grand Prix on the starting line today, and four of them are Michael Schumacher.

It would be really hard to get serious about anything political today unless it was a joke.

In thinking about nanotechnology today, what's most important is understanding where it leads, what nanotechnology will look like after we reach the assembler breakthrough.

Today, they're just up there for the money, just packaged and be gone.

We usually lose today, because there has been a yesterday, and tomorrow is coming.

But the real focus should be on people who are buying today because the base is so big it will take a long time for any change materialize on an overall basis.

At times, we were forced to go through a history of dependence, unable to determine our own destiny. But today, we are at the threshold of a new turning point.

I was part of it, and I am still part of it today in terms of what it means to a whole new generation of people who are interested in the enduring energy, achievements, spirit and creativity that exemplified our era.