It's a fascinating element.

Very poisonous compounds.

Murders have been carried out with it.

It has some very nice connections with ancient wallpaper on dhe.

Neil is going to show you a whole series of experiments.

Oh, the books say that our snake looks metallic that our sample looked a bit brown, so new heated it in a test tube.

Are snakes interesting?

It doesn't melt.

It's sublime.

Sze.

When you heat it, that is.

The vapor is formed and condenses on the side of the vessel.

And if you look carefully, you can see it makes a very nice metallic film.

Often called an arsenic mirror.

Our snake is particularly famous as a poison.

People used it to get rid of their lovers, their wives, or just talk with people.

And the compound they used is arsenic oxide A S 406 Now we didn't have a sample of this, so we decided that Neil would make some forests.

So he began by dissolving all snick in dilute nitric acid.

There's quite a violent reaction, lots of bubbling and it forms the gas N o nitric oxide which is colorless.

But it reacts with air to give nitrogen dioxide, which is brown, so you can see brownish fumes coming out with the test tube.

The takes books say that when you dissolve our snake in nitric acid, you make a solution off the oxide.

We want the poisonous oxide.

It's meant taste of sugar.

Neil set up very nice filter system.

Pour the solution in and it came through.

There must say it did still look a little brown, but we were really hopeful we were going to get our white powder.

The next stage, of course, is to go from solution to solid, so you have to evaporate off the water.

It was a bit slow process.

I got bored and went out while Neil was finishing it.

That's pure failure.

What a disappointment.

Instead of this lovely white powder, there was some sticky brown solid, I presume, because we've still got some particles of arsenic in the white powder.

At least we tried, but I still think it's probably our snake oxide.

The reason they used arsenic oxide, which they could easily get it.

It was a white powder.

It tasted sweet, so it wasn't very noticeable if you mixed it with sugar.

So our brown stuff is not going to be much use for poisoning people.

Fortunately, we're not going to try.

I have two favorite stories about poisoning.

Both of them are true.

The 1st 1 happened in a town in the north of England called Bradford.

It happened in 18 58 in October.

In those days, sugar was quite expensive, so people who made sweets were very dishonest and added some cheap powder to the sugar so that they didn't have to put so much sugar in the sweets.

They called this white powder deft.

On this particular occasion, a sweet maker called Jon Neal sentence his lodger to go and get some daft to put in his next batch of sweets.

He called them lots inches, and he went to the next town on DDE, went to a pharmacist, and the pharmacist told his assistant to go and fetch the deft, which was the white powder.

And unfortunately, he didn't explain correctly.

So the pharmacist sold £12.

That's five kilos off arsenic oxide to the unfortunate customer.

This was mixed in with the sweet mixture on dhe, more than 20 people died of arsenic poisoning in Bradford, and more than 200 were really ill.

And this was one of the things that led to a greater control of arsenic in the United Kingdom.

The other case took place in the early 19 twenties in the town in the west of England called Hay on Wye.

The attacks were carried out by a solicitor, a lawyer, who in fact was the only lawyer who's ever been hanged in the UK It is believed he poisoned his wife with our snake over a period of several months, and then one of his business rivals was invited to tea.

The lawyer passed a scar on a little cake in his fingers to his rival, and as he passed it, he said, Excuse fingers, and in that moment it is believed he put arsenic on the cake.

His guest was very ill on.

Dhe was found to have been poisoned with arsenic, so they exhumed the body of his wife, dug it up and it was full of arsenic.

So he was tried on Dhe, convicted and executed, and that should be said that he always denied that he had done this that when he was arrested, he did have all snick powder in a packet in his pocket that he had good white powder.

Our brands, like he had nice white powder.

The question is, how did they find our snake in the body of his dead wife, who had been under the ground for several months?

And it's with a very clever test that was invented in the early 19 century cold marshes test on Neil decided he would like to do marshes test to the first thing you have to do.

Is that ad metallic sink.

I was really excited.

I was allowed to chop up the sink.

You put in the pieces of sink into round bottom flask, and then you add whatever you think contains arsenic in our case, a small amount of Neil's brown sludge and then from a dropping funnel.

You drop in, dilute sulfuric acid on the sulfuric acid, reacts with the sink and generates hydrogen on the hydrogen, reacts with the arse nick and makes a compound which has a similar formula.

Tow ammonia.

But it has three hydrogen sze attached arsenic rather than three hydrogen sze attempts to nitrogen, which you have in ammonia on this compound called our scene his very volatile.

It's the guests.

As the hydrogen streams off the reaction, it takes the whole scene with it.

You're then meant to light the stream of hydrogen coming out of the nose along the top of the apparatus.

If it's just hydrogen coming out, it would be colorless.

And Brady was absolutely convinced that we would see a colors list flame, and he could tell us how bad we've bean at the experiment.

My goodness, it works.

I can't believe it worked.

That's amazing.

Yes, You happy?

Yes.

So the murderer is a guilty man.

Much toe All our surprise.

The flame came out a beautiful lavender color.

Lavender is the color that arse Nick Burns with, but the rial elegance of marshes test is that if you put a cold surface, a piece of glass or a piece of porcelain into the flame wth E, I'll seen does not burn completely.

So you get a thin film off arse Nick on the surface.

The importance of this was that once the films there, it will stay there so it could be taken to court to be shown as a piece of evidence, and you could say, Look, arse Nick came out of the woman's stomach or whatever the sample was that you had.

There's another, completely different way that people in the 19th century were poisoned by arsenic, and that was from the green coloring, the green pigment that was used in their wallpaper.

This green pigment is a cop assault called Sheila's Green.

It is made by taking a solution of sodium meta last night, which is colorless and dropping in copper sulfate, which is blue.

I've done this reaction several times, but I haven't done it for a long time, and I was really surprised quite how beautiful it is, saying this green solid, forming sealers green was used quite widely.

This would be fine, except in those days people were really frightened of drafts on.

They usedto close all the windows and doors and have very stuffy rooms, which were not very well heated.

So particularly at night when they were asleep, there was a lot of condensation, and mold would grow on the wallpaper.

And so the mold growing on your wallpaper could create a gas containing arsenic, which, if you were lying asleep in this airless room over a period of just one night would be enough to kill you.

In October 18 15 Napoleon Bonaparte was brought a prisoner to the island of Santa Lena in the South Atlantic.

Yeah, he was to spend the last six years of his life here.

He died on the fifth of May 18 21.

Examination was made of specimens of hair sitio being taken from the head of Napoleon both before and after he died.

Results established the presence of arsenic.

My friends, David Jones, who was an expert in really weird chemical facts, wondered whether the stories of Napoleon being poisoned with arsenic by the wicked British could in fact be due to mold on the wall paper into his house on the island of ST Elina, where he was exiled.

Remarkably, David managed to get hold of a sample off Napoleon's wallpaper, which had some green marks on it.

Andi, He could analyze this and show that it did indeed contain arsenic, and there was enough else Nick and Napoleon's wallpaper to explain the arsenic that had been found in his hair but not enough to have killed him.

So, according to Davis, experiments.

The British did not poison Napoleon, but he just felt unwell because of his green wallpaper.

The action of mold on arsenic compound was exploited for real chemistry by a Nostra alien chemist called Bruce Wild on Dhe, his technician Pull Gungan.

They did a really unique experiment.

They got some bread and injected it with an arsenic compound that was not volatile and then put the bread in a large container and let mold grow on it.

The mold converted the arsenic compound in tow.

Volatile compound gas.

Then they let this through a tube into a solution, and they got a yellow solution of a new complex.

And the reason they used the mold is because, unlike human chemists, the mold could produce a so called optically active compound that is a left handed version of the molecule without the right handed one, whereas ordinary chemists produce both at the same time.

And they published great paper and they had an extraordinary photo of pull the technician holding this loaf of bread full of arsenic.

I dread to think what their safety assessment looked like.

This piece of metal has an extraordinary story about it, which involves arsenic.

When I first came here to noting him, one of my colleagues, Mike, was studying the reactions of arsenic with liquid Floren.

If it's done carefully, this is a nice controlled reaction.

You have to do it with the operators cooled in liquid nitrogen.

So he was doing the reaction inside a thermos flask that looks like this on dhe.

Something went wrong, and there was an enormous explosion.

All that was left of the thermals waas, the plastic top on this piece of metal.

Everything else was distributed around the lab.

But I think the importance of this is to show you that our snake, if you get it in the right state or perhaps I should say the wrong state can react very violently.

I went into the lab before it had been cleaned up and retrieved this because I was just so amazed by it.

And I used to use it when I was teaching about arsenic chemistry.

Apparently, metallic arsenic can occasionally be found in natural minerals that usually its founders compounds.

And in our store we have a sample of one of the minerals containing arsenic that's called Rielle Gar.

It's an arsenic sulfide which has really very nice red crystals.

Unfortunately, as sample has rather small crystals, if you look at them under a microscope, you can see really nice red crystals, which are of arsenic sulfide.

And this is probably way Arsenic compounds were known, even in ancient times, because of these brightly colored minerals.

While we were filming, Neal found some amazing old papers, lead acid, ate papers for testing for arsenic.

They were labeled 20th of July 1942 before any of us were born.

So we tried these papers out, tried testing them on some of Neil's mixtures that it made.

We were expecting the papers to go black.

However, nothing much happened.

We haven't thrown them away because one of you may know how to use these papers.

Or we may find out some instructions because Matt doesn't for anything away.

It is said that arsenic was discovered by a German bishop called Albertus Magnus, who is buried in the city of Cologne in Germany.

And about a year ago, I gave a lecture in Cologne on the students took me to see his grave on DDE.

They made a couple of little videos of me looking at it.

Notice Professional s Brady or James, but still quite fun.

Albertus Magnus has really significance in Cologne.

To current PhD students, there is a tradition that when they graduate successfully, when they finish their doctorate, they dio to his statue and they touch his thumb as a sign of good luck for the future career.