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.

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.

This joy of discovery is real, and it is one of our rewards. So too is the approval of our work by our peers.

Higher education must lead the march back to the fundamentals of human relationships, to the old discovery that is ever new, that man does not live by bread alone.

Whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.

Mistakes are the portals of discovery.

We had avoided discovery by the Sioux scouts, and we were confident of giving them a complete surprise.

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.

The most wonderful discovery made by scientists is science itself.

If there's one thing for which I admire you, it's your original discovery of the Ten Commandments.

A man's errors are his portals of discovery.

As soon as the news of the Cabot voyages reached the King of Portugal he arranged to send an expedition of discovery to the far north-west, perhaps to find a northern sea route to Eastern Asia.

Discovery consists of seeing what everybody has seen, and thinking what nobody has thought.

The discovery of truth is prevented more effectively, not by the false appearance things present and which mislead into error, not directly by weakness of the reasoning powers, but by preconceived opinion, by prejudice.

The initial motivation of the experiment which led to this discovery was a subconscious feeling for the inexhaustible wealth of nature, a wealth that goes far beyond the imagination of man.

A man of genius makes no mistakes; his errors are volitional and are the portals of discovery.

Using the power you derive from the discovery of the truth about racism in South Africa, you will help us to remake our part of the world into a corner of the globe on which all - of which all of humanity can be proud.

I love to create interesting textures with language. You can do it as long as it seems like a discovery.

Second issue is the rapidly accelerating increase in the number of vulnerabilities that get discovered every day. And, equally importantly, is the shortening of time between the discovery of the vulnerability and the release of an exploit.

The folly of mistaking a paradox for a discovery, a metaphor for a proof, a torrent of verbiage for a spring of capital truths, and oneself for an oracle, is inborn in us.

What everyone in the astronaut corps shares in common is not gender or ethnic background, but motivation, perseverance, and desire - the desire to participate in a voyage of discovery.

As was to be expected, the discovery of the nervous apparatus of the salivary glands immediately impelled physiologists to seek a similar apparatus in other glands lying deeper in the digestive canal.

The discovery of agriculture was the first big step toward a civilized life.

Love is but the discovery of ourselves in others, and the delight in the recognition.

We are concerned that, in a few years time, this place of discovery, with its wealth of human fossils, the like of which can be found nowhere else in the world, could be completely destroyed.

This led to the discovery that long chain fatty acids would remarkably stabilize serum albumin to heat denaturation, and would even reverse the denaturation by heat or concentrated urea solutions.

In animation, there's this exhilarating moment of discovery when you see the film and you say, Oh THAT'S what I was doing.

The process of my transformation came to a head with my discovery of St. Francis of Assisi during a pilgrimage I went on with a scout troop from my school.

In examining the evidence of the Christian religion, it is essential to the discovery of truth that we bring to the investigation a mind freed, as far as possible, from existing prejudice, and open to conviction.

In our case, finding a Lucy is unique. No one will ever find another Lucy. You can't order one from a biological supply house. It's a unique discovery, a unique specimen.

The only real voyage of discovery consists not in seeking new landscapes but in having new eyes.

And of all illumination which human reason can give, none is comparable to the discovery of what we are, our nature, our obligations, what happiness we are capable of, and what are the means of attaining it.

If we insist that public life be reserved for those whose personal history is pristine, we are not going to get paragons of virtue running our affairs. We will get the very rich, who contract out the messy things in life the very dull, who have nothing to hide and nothing to show and the very devious, expert at covering their tracks and ambitious enough to risk their discovery.

The greatest discovery of my generation is that a human being can alter his life by altering his attitudes.

My experience of ships is that on them one makes an interesting discovery about the world. One finds one can do without it completely.

Yeah, it is, because it's a real discovery of your inner resources, you know. That's what my character is all about and what my playing is all about. But to get up there and just go inside and draw out something that makes you feel good first and foremost.

We learn wisdom from failure much more than from success. We often discover what will do, by finding out what will not do; and probably he who never made a mistake never made a discovery.