I've got a picture of it on my table, and Brady is actually being to see it.

It's being repaired at the moment, and he's watched how it is being treated and the chemistry behind it.

You, as a paper conservative, must have looked at this and thought, This is a big deal.

But first of all, most of you know that lecture theaters, classrooms all over the world have periodic tables hanging in them.

Clearly, when Mendeleev invented the periodic table, nobody had won in their labs.

Electra theaters and sometime people must have started hanging them up.

The periodic table that I'm talking about was found under a lecture theatre in the storeroom.

The University of ST Andrews in Scotland, the new head of department, was ordered to clear out this old store room, probably for fire safety or something like that.

On among the objects, they found a rolled up periodic table and securities, and if you look at it there many things a bit surprising.

So first of all, it's in German.

That's not totally surprising because in the 19th century, Germany was the leading country for chemistry.

Mendeleev wrote his papers in German quite often, the second thing is that men delay.

It is spelt in what looks like a really strange way.

Tow us again.

Every language has a different way of translating or trance literate ing Russian letters on DSO in German This is what men did life looks like.

Actually, it's not German.

This periodic table it was Austrian.

It was made in Vienna, and the key question is, what is the date?

It has to be after 18 69 because that's when Mendel a first proposed the periodic table on in this form that's on the picture he only proposed in 18 71 but weakened ate it rather like new conduct periodic tables.

Now, by looking at the names of the recent elements that are on it.

There is gallium, which was one of the elements predicted by Mandalay VE, which was discovered in 18 75.

So it must be later than 18 75.

And then there is also scanned IAM, which was discovered in 18 79.

But there is a hole for element atomic weight 72 which is Jemaine IAM.

And since this is in a German language, it's almost inconceivable that the people would not have printed Jemaine Ian the element named after Germany if it had been discovered.

Domain name was discovered in 18 86.

So we have a bracket.

It's somewhere between 18 79 and 18 86.

I don't know.

I fancy 18 80 for no particular reason except seems about right.

Then there's some other quite interesting features.

First of all, there's a slightly strange element down here.

D I, which is must be one of the rare earth on dhe.

The elements lan thin, um, and cirie, um are the other way round from what they are now because they have rather similar atomic weights on dhe.

The elements were arranged by atomic weight on Mendeleev Got that wrong.

The other question, which I think is really very interesting, is of course, in 18 80 people did not know about electrons, so they did not know about atomic number.

So how did they justify to the audience looking it on the wall?

How did they justify the order of the elements?

And if you Look here.

There is a first row which explains the mechanism off.

They will, the way they rationalized it, explained it and they used it on the basis of the formula of the oxides, beginning with R tuo.

Quite strange that they should have used the letter R for a metal and going all the way across here to this end, Group eight, which is R o fool, you noticed that they've got the numbers superscript rather than sub script that we have now.

We would now have the full further down, and they also have for some of these elements, like carbon, they have the formula of the hydride.

So here you've got R H four like methane ch four and so on.

So there was a sort of rationalization for the elements.

Gold is on there twice, Professor.

So you see in the bottom left corner and the bottom right corner.

Oh, I hadn't noticed that.

Well, gold is twice as good as any other elements that shows that they weren't quite sure where some of these elements went.

Brady was really lucky.

I'm quite jealous.

He went to see the conservative who was restoring this periodic table to his good estate as possible.

The conservative talked about how they were trying to increase the pH by quite a clever piece of chemistry, reacting magnesium bicarbonate with the acidity in the paper itself.

So this treatment now has got to that stage where it has bean washed on.

It's also bean de acidified that was done by immersion in a dilute solution off magnesium bicarbonate or magnesium hydrogen carbonate.

Look at you using your periodic table.

No way.

Here we are.

It is here in black, black and white.

We wouldn't find one like this in the University of Nottingham because University of Nottingham only started as a university in 18 81 and I didn't think chemistry started till several years later.

But I think it's important to remember that periodic tables were not very common for quite a long time.

Even my first chemistry book on the inorganic chemistry didn't have a periodic table, then it when I was at high school that the lab had a nice one.

But I think I'm really pleased that the sharp eyes of the chemists at ST Andrews made told that this was preserved and that it will be kept for posterity.

The way understand?

The university archives in ST Andrews are taking it for safekeeping so it won't be hanging in the chemistry department, which is a pity.

But you have to look after the result effects in the proper way.

Now, just as a little bonus, we've got another chart that Richard's been conserving.

Also for the University of ST Andrews.

Do you think you might show us that one?

Absolutely.

Look at this.

Let's see how quickly people can figure out what this is as it gets unrolled.