We always think of these scientists in the past

as being saints.

And here he is sitting in his office thinking

"Hee hee I've made my competitor feel uncomfortable"

And in a way it's sad that we lose these

bits of information because

it makes science seem so much more exciting.

We're in the library of the Royal Society

Looking at letters about Radon.

Radon is the heaviest of the noble gases

and in the early nineteen hundreds

there was still a big argument about

the work and trying to isolate Radon.

Radon is given off as a gas

in the radioactive decay of Radium.

Radium decays radioactively

emitting an alpha particle - that's a nucleus of Helium

with the mass 4 - and generates Radon.

Radon is itself radioactive and decays so

you have to have it, as it were, freshly made. Rather like

you can only get fresh meat. If you keep it for a long

time it decays away.

The half life of the most stable isotope of Radon

is just over three days so it's really relatively

short lived. That means if you have a certain amount of

gas, after three days you'll only have half of it.

Another three days a quarter of it.

And by the time you come back from your holidays

most of it's gone.

In the days that this letter was written,

the way they were getting it was from

the decay of Radium. In fact I've read - and this is quite

exciting. It's the first time you've ever seen a glass

in the library because they're strictly forbidden. -

The way they did it was to take a glass vessel

and fill it with water.

Imagine now you have a container of water with a

piece of Radium metal at the bottom.

It is breaking down, generating Radon gas

and bubbles of this gas

will go up to the top.

very small amounts of gas, bacause Radium

doesn't decay very fast.

And so, we can imagine that

Rutherford and Ramsay are really competing to get

the first sample to characterize it.

And because it also contains alpha particles,

it will be contaminated with Helium.

You've got to realize that these famous scientists

were extraordinarily competitive.

They wanted to get there first.

And they considered the other one,

really a bit of a scoundrel.

And so there was a sort of competition which is

difficult for us now to imagine.

And in fact Rutherford was really rude about

Ramsay's work. He says, his work - that's Ramsay's

work - is all right superficially, on the surface,

but when you get down in it you begin to see

the nothingness of it all. So he thinks it's rubbish.

So this is in a private letter to his friend Schuster -

Schuster was his surname -and he begins,

"My dear Schuster", because in those days you called

your friends by their surnames. No first names;

It wasn't right.

And this was written on July 30th 1908,

so more than a hundred years ago.

The reason he's written this letter,

is because he's real excited he has got a spectrum

of this Radon gas.

It wasn't called Radon then; It was called

Radium Emanation - Emanation means "coming out

of Radium."

And he's got a spectrum, and Ramsay hasn't.

It was really quite exciting.

And so he sent a photograph.

And, this is the photograph.

So, Rutherford has signed this

and he said, "Some of the lines run together

in the reproduction" - that's the print - "

and ??? they're quite clear in the negative"

So, he had an experiment in which he had a small

amount of this gas, not more than 0.2

of a cubic centimeter, so it's not very much, in which

presumably, though he doesn't say so, he put

an electric discharge through it so that the gas glowed.

Rather like a Neon sign glows red in a shopping center.

And he then photographed this light coming out

with a photographic film, using a spectroscope to

spread out the different colours.

All these gases give a whole series of lines

and this is a print of his photograph,

because you get a negative in the pho... originally

and then he's printed it.

If you come close you can see it says the

"SPECTRUM OF RADIUM EMANATION"

There are actually three spectra here.

At the top and the bottom are the spectra of

Helium gas as a calibration so that he can see

what the wavelengths are.

And he's written, all the way down here, the

wavelengths of the Helium lines.

You can see Rutherford has fantastically good

small handwriting, or it might have been his assistant,

Kay, who wrote this, because his handwriting looks

pretty difficult to read.

And then, in the middle, is the spectrum of Radon -

Radium Emanation

It shows that Radon is a completely separate element.

And he's really excited because this is the first spectrum

that he believes in.

Ramsay claims to have got a spectrum, but Rutherford

doesn't believe him.

I don't know, because it doesn't say here, whether

Rutherford ever published this spectrum apart

from just sending it to his friend, but it sounds as if he's

going to publish it, because he wrote, "I think Royds" -

that's his colleague - "and I, have certainly succeeded

in making Ramsay temporally very unhappy."

We always think of these scientists in the past as

being saints. And here he is sitting in his office thinking,

"Hee hee I've made my competitor feel uncomfortable."

Do you ever feel like that when you get one up on

your scientific colleagues/collaborators/rivals?

You say it's a wonderful thing and a human thing.

Let me put you on the spot. Do you ever take delight

in beating people to things?

I don't usually get quite so aggressive, perhaps it's not

my nature, though I did get quite excited when I made a

compound that my German friend, Friedrich, couldn't

and I felt really quite good about that, but in a friendly

sort of way. I was not hoping that he would be sitting

there, um, crying or whatever, but there are stories of

Nobel prize winners tearing up journals or jumping

up and down on the journals when their rival

has published something else.

And I think it's important to realize that it's good

to feel emotional about these things because then

you may have better ideas.

If you're sitting there, cold and calculating and not very

involved, perhaps you won't have the brilliant

breakthrough that you might do otherwise.

I don't know what happened. I suspect that Rutherford

became more interested in the structure of the atom

and, having got this and so on, lost his enthusiasm

or got more excited about something else, because

in the end, if you look in the books, it's Ramsay who's

credited with discovering Radon, though according to

some sources, he didn't want to call it Radon and he

thought of a nice name, he wanted to call it Niton

for some rather obscure Latin derivation.

But I think Radon is a nice name. It sounds a bit

like Argon or Xenon and also, it connects it very nicely

with Radium. So, as names go, it's really quite a good

and understandable name.

As far as I know nobody has really studied the

chemistry of Radon in much detail but, because it's

below Xenon in the periodic table there will be quite an

extensive chemistry. You will be able to make Fluorine

compunds, probably oxides and a variety of other ones.

And generally, as you go down the periodic table

the chemistry of the noble gases gets richer and richer.

A couple of years ago, Brady and I went to an institute

in Germany, in Darmstadt, and they had a display

for the public of a cloud chamber.

Ok we have a cloud chamber here and I will now inject

radioactive Radon gas into the chamber and you will see

that there is a lot of radioactive decay going on

when I inject it.

So now we have to wait a second for the gas inside

And Brady and I sat there for some time, watching these

trails, which look really very beautiful.