[MUSIC] As I said, poisoning is very ancient. And in the ancient world, poisoning was certainly very widespread. One of the most famous of all poisonings is the death of the Greek philosopher Socrates, in 399 B.C. Socrates had been convicted of various crimes, including corrupting the youths of the city of Athens. Well, in those days, corrupting the youth didn't mean what we might think it means today. What Socrates had done was encourage the youths of Athens to actually think, and that was considered a very bad thing then. Well, Socrates, for these so-called crimes, was sentenced to death, and the means of execution was drinking poison. One of the poisons he drank was the extract of a plant called hemlock, and hemlock contains various different alkaloids. One of the major ones is coniine. Now, we know that Socrates was poisoned by hemlock because he was allowed to have some of his friends around during the execution, and one of these, Plato, wrote down exactly what happened. And from the symptoms, we can deduce that it was hemlock. So after drinking the poison, Socrates experienced numbness, starting with his feet, moving slowly up the body as the alkaloids in the hemlock paralysed him. And of course, when that paralysis reached his heart and lungs, then he died. Nowadays, we treat our philosophers a little bit better than this. Another famous historical poisoning, at least according to the stories that we're told, is that of the first Roman Emperor, Augustus Caesar, in 14 A.D. Now, what we are told is that Augustus was poisoned by his wife, the Empress Livia. According to the stories, Augustus suspected his wife. He thought that she, or someone else, was very, very likely to poison him. So, he started to refuse to eat any food that was prepared for him. In fact, he refused to eat anything except the figs that he picked with his own hands from his own personal fig tree. But, according to the stories, Livia was too clever for him, and what she did was to take the poison and inject it into the figs growing on the tree, so that he would pick them and eat them. That's ancient poisoning, but some things don't change. This is a rather tragic tale from just a few years ago concerning this unfortunate man, Lakhvinder Cheema, who lived in London. And he'd had a long relationship with this lady, Lakvir Singh. But then their relationship had ended, and he found himself a new fiancée who he was going to marry. Well, Lakhvinder Cheema and his fiancée had dinner one night. They were eating some leftover curry from the refrigerator, and soon after, they both became extremely ill. So he called the emergency services, and he tried to tell the emergency services that he had been poisoned. But as I said, poisoning is not very common nowadays. So at first, the guy answering thought that he was saying he had food poisoning. But no, he explained, he thought somebody had poisoned him. And the emergency responder asked, who would want to do a thing like that? And he said, his ex-girlfriend, and then they understood. So the ambulance was sent to take him to the hospital, but it was too late, and he died soon after. [BLANK_AUDIO] His fiancée survived. She was very ill, but she survived. And the reason, it appears, that she survived is that she only had had one helping of the curry, whereas he had had two. Well, ultimately, the ex-girlfriend, Lakhvir Singh, was convicted of this crime and sentenced to spend a minimum of 23 years in prison. Now, how had she done this poisoning? How had she got such a potent poison to kill him just with one meal of curry? And the answer is this plant here, Aconitum Ferox. Now, this plant is native to the Himalayas and it's been used for centuries as a poison in India. And Lakhvir Singh had travelled to Northern India, travelled to the Himalayas, to collect this plant, and she brought it back with her. She'd gone into Cheema's house, she'd been seen putting something in his refrigerator, and it's assumed that what she'd done was put this plant in the curry. Indeed, traces the plant could be found in her clothes and in her handbag, leading to her conviction. The reason this plant is so toxic is that it contains this very complex alkaloid here, called pseudaconitine, and this is another of these alkaloids that will shut down the nervous system. Like many alkaloids, even though it can shut down the nervous system, it cannot penetrate the brain. So the horrible thing about this kind of poisoning, as happened to Lakhvinder Cheema, is that even though the body is shutting down, the brain is still working, and the person is completely aware that they are dying, but there is of course nothing they can do about it. Well, there is a moral to be drawn from this tale. So, as the poet said, as William Congreve said, "Hell hath no fury like a woman scorned." So, if there are any young men watching this lecture, the lesson to you is to treat the ladies right, otherwise your curry may be a lot spicier than you expect. Plants can also be a cause of accidental poisoning. It doesn't have to be deliberate. Here, for instance, is wild garlic, and this is a really good stuff. It has a wonderful garlic flavour. And I read a report of a man in Croatia who used to go out into the woods and collect wild garlic leaves, because he liked to put them in his salads. Well, if you're going to do that, you have to know your botany, because this person also collected some of a plant called Meadow saffron by mistake. Meadow saffron is very toxic and it led to his death. Meadow saffron is toxic because it contains this compound, colchicine. Now, colchicine is an interesting compound, because it is actually used as an anti-cancer compound. It will kill cancer cells, and it can be used to help cure this disease, provided it's used in the right dose. But this man's salad had obviously contained an overdose of colchicine, leading to his death. Some other very common plants are also toxic, for instance, the potato plant. Now, pretty much all of us eat potato quite a lot and we don't think of potato as a source of poison. Well, the reason is that the only part of the potato we eat, typically, is the tuber, which is perfectly harmless. But the fruit of the potato plant, which looks a little bit like a green tomato, is toxic. It contains a chemical called oxalic acid. It's not very toxic, it's unlikely that potato fruits would kill an adult, but they could have serious, serious effects, for instance, on a child. Another plant that contains oxalic acid is rhubarb. Rhubarb is eaten quite widely around the world. It's also a part of Chinese, traditional Chinese medicine. But when we eat rhubarb, we are always careful to only eat the stems, the nice bright red stems. It's the leaves that contain oxalic acid. So if you eat rhubarb leaves, you can become really quite ill. [BLANK_AUDIO]