根据着名毒理学家帕拉塞尔苏斯的说法，“剂量会产生毒药。”换句话说，如果你摄取足够的化学物质，每种化学物质都可以被视为毒药。一些化学物质，如水和铁，是生命必需的，但有适量的毒性。其他化学品非常危险，它们只是被认为是毒药。许多毒药具有治疗用途，但少数毒药在谋杀和自杀方面获得了优势。以下是一些值得注意的例子。 Belladonna（Atropa belladona）的名字来源于意大利语bella donna的“美丽女士”，因为该植物是中世纪流行的化妆品。浆果汁可以用作腮红（可能不是唇膏的好选择）。在水中稀释植物提取物使得滴眼液使瞳孔扩张，使得一位女士似乎被她的追求者所吸引（这种效果在一个人恋爱时自然发生）。传说中，麦克白在1040年使用致命的茄子来毒害丹麦人入侵苏格兰。有证据表明连环杀手洛芙塔可能使用茄属植物杀死了罗马皇帝克劳迪乌斯，与阿格里皮娜的年轻人签约。很少有确认的致命茄属植物意外死亡病例，但有一些与Belladona有关的常见植物会让你生病。例如，有可能从马铃薯中获得茄碱中毒。植物的另一个名字是致命的茄属植物，有充分的理由。该植物富含有毒化学物质龙葵碱，莨菪碱（scopalamine）和阿托品。最着名的铁杉中毒病例是希腊哲学家苏格拉底的死亡。他被认定犯有异端邪说，并被他自己的手判处饮用铁杉。根据柏拉图的“Phaedo”，苏格拉底喝了毒药，走了一会儿，然后注意到他的双腿感觉很重。他躺在他的背上，表示缺乏感觉和寒意从他的脚向上移动。最终，毒药到达了他的心脏并且他死了。来自植物或其浆果的果汁用于向毒箭尖箭。吃一片叶子或吃掉10片浆果会导致死亡，尽管有报道称一个人吃了大约25个浆果并且活着讲故事。蛇毒是一种令人不快的自杀毒药和一种危险的谋杀武器，因为为了使用蛇毒，必须从毒蛇中提取毒药。可能最着名的使用蛇毒是Cleopatra的自杀。现代历史学家不确定克娄巴特拉是自杀还是被谋杀，而且有证据表明有毒药膏可能导致她死亡而不是蛇。如果Cleopatra确实被一个asp咬了，那就不会是一个快速无痛的死亡。一个asp是埃及眼镜蛇的另一个名字，这条蛇是克利奥帕特拉熟悉的。她会知道蛇的咬伤是非常痛苦的，但并不总是致命的。眼镜蛇毒含有神经毒素和细胞毒素。咬伤部位变得疼痛，起水泡和肿胀，而毒液导致瘫痪，头痛，恶心和抽搐。死亡，如果它发生，是来自呼吸衰竭…但只有在其后期阶段，一旦它有时间在肺部和心脏上工作。然而实际事件发生了变化，莎士比亚不太可能做对。毒性铁杉（Conium maculatum）是一种高大的开花植物，其根部类似于胡萝卜。植物的所有部分都含有丰富的有毒生物碱，可导致呼吸衰竭导致瘫痪和死亡。接近尾声时，铁杉中毒的受害者无法移动，但仍然意识到周围环境。
According to the famous toxicologist Paracelsus, “the dose makes the poison.” In other words, every chemical can be considered a poison if you take enough of it. Some chemicals, like water and iron, are necessary for life but toxic in the right amounts. Other chemicals are so dangerous they are simply considered poisons. Many poisons have therapeutic uses, yet a few have gained favored status for committing murders and suicides. Here are some notable examples. Belladonna (Atropa belladona) gets its name from the Italian words bella donna for “beautiful lady” because the plant was a popular cosmetic in the Middle Ages. The juice of the berries could be used as a blush (probably not a good choice for lip stain). Diluting extracts from the plant in water made eye drops to dilate the pupils, making a lady appear attracted to her suitor (an effect that occurs naturally when a person is in love). Legend has it, Macbeth used deadly nightshade to poison Danes invading Scotland in 1040. There’s evidence that the serial killer Locusta may have used nightshade to kill the Roman emperor Claudius, under contract with Agrippina the Younger. There are few confirmed cases of accidental deaths from deadly nightshade, but there are common plants related to Belladona that can make you sick. For example, it’s possible to get solanine poisoning from potatoes. Another name for the plant is deadly nightshade, with good reason. The plant is high in toxic chemicals solanine, hyoscine (scopalamine), and atropine. The most famous case of hemlock poisoning is the death of the Greek philosopher Socrates. He was found guilty of heresy and sentenced to drink hemlock, by his own hand. According to Plato’s “Phaedo,” Socrates drank the poison, walked a bit, then noticed his legs felt heavy. He lay on his back, reporting a lack of sensation and chill moving upward from his feet. Eventually, the poison reached his heart and he died. Juice from the plant or its berries was used to tip arrows with poison. Eating a single leaf or eating 10 of the berries can cause death, although there is a report of one person who ate about 25 berries and lived to tell the tale. Snake venom is an unpleasant poison for suicide and a dangerous murder weapon because in order to use it, it’s necessary to extract the poison from a venomous snake. Probably the most famous alleged use of snake venom is Cleopatra’s suicide. Modern historians are unsure whether Cleopatra committed suicide or was murdered, plus there is evidence that a toxic salve might have caused her death rather than a snake. If Cleopatra was indeed bitten by an asp, it wouldn’t have been a quick and painless death. An asp is another name for an Egyptian cobra, a snake with which Cleopatra would have been familiar. She would have known the bite of the snake is extremely painful, but not always lethal. Cobra venom contains neurotoxins and cytotoxins. The bite site becomes painful, blistered, and swollen, while the venom leads to paralysis, headache, nausea, and convulsions. Death, if it occurs, is from respiratory failure… but that’s only in its later stages, once it’s had time to work on the lungs and heart. However the actual event went down, it’s unlikely Shakespeare got it right. Poison hemlock (Conium maculatum) is a tall flowering plant with roots resembling carrots. All parts of the plant are rich in toxic alkaloids, which can cause paralysis and death from respiratory failure. Near the end, a victim of hemlock poisoning can’t move, yet remains aware of his surroundings.