The Poison Book Transcript

Caroline: "Poison book" or "poison register" is a phrase that crops up quite a bit in golden age detective fiction. I'm sure lots of you have come across it in this fictional context, where a character is asked to sign such a volume so as to create a paper trail for a purchase that definitely isn't anything suspicious or murder-related. Agatha Christie, Dorothy L. Sayers, Anthony Berkeley and others all had great fun weaving plots around this quirk of interwar pharmaceutical regulation.

But what really was the point of the poison book, and how did it come to be such a familiar part of British life that writers could drop it into their crime fiction with no further explanation? Why were people able to walk into any high street pharmacy and casually buy large quantities of incredibly toxic substances anyway? To find out, we're going to have to take a trip back to the nineteenth century and think a lot about arsenic.

Music

Welcome to Shedunnit. I'm Caroline Crampton.

Music

Before listening further, please note that this episode contains full spoilers for the plots of The Mysterious Affair at Styles by Agatha Christie, Strong Poison by Dorothy L. Sayers, The Wychford Poisoning Case by Anthony Berkeley and Family Matters by Anthony Rolls. You have been warned.

Joining me on this voyage of poisonous understanding is Dr Kathryn Harkup, a former chemist, crime fiction fan and the author of excellent science books including A is for Arsenic: The Poisons of Agatha Christie. Kathryn has been on the show several times before to bring a scientific dimension to our understanding of detective fiction, most recently on the green penguin book club episode about The Mysterious Affair at Styles.

And now, it's time to travel back in time.

Music

The story starts in 1851 with the Arsenic Act, which is the first time that the British government attempts to put down anything in law to say, actually maybe not a great idea to sell people poisons freely.

Kathryn: Absolutely unregulated sale of whatever the hell you want by whoever to whoever. Absolutely extraordinary that it took until 1851 for anyone to go maybe we shouldn't do that.

Caroline: And then in the 1850s, there comes this first attempt to make a law about it. Is there a particular atmosphere that prompts legislators to do that?

Kathryn: There have been a few prominent cases. It was becoming quite notorious that arsenic was being used fairly freely to kill people and there was now a test that was available that was extremely sensitive so it could be detected, but actually they thought maybe we should prevent rather than just judge after the event.

There were also a number of accidents where people had bought the wrong thing because arsenic, the stuff that's used as a poison, it's white arsenic and it just looks like sugar or flour. And there were no regulations about labelling or anything, so mistakes happened. So I think as much as anything, it was to avoid mistakes as much as murderers, but the legislation that was put in place was pretty limited.

Caroline: Tell us a bit about what it actually involved.

Kathryn: The basic rules were if you went into a shop and you bought arsenic, you had to be known to the person, or you had to have a reference and you would write your name, your address, what you were buying, how much, what it was for into a physical book, a poison register or poison book that was kept in the shop, and the person who sold it to you would also sign it.

So this is a system of traceability. So in theory, if someone suddenly drops dead in the road, they can ask around at different pharmacies, see if anyone's bought a lot of arsenic recently. The idea of preventing accidents, they also incorporated rules about colouring the arsenic. So if you were buying a domestic amount of arsenic, say to kill rats, or as a weed killer, whatever, then if it was below a certain quantity, it had to be coloured with indigo dye or with soot so that it couldn't be mistaken for sugar or flour. So there were a few things, but it's a bit basic.

Caroline: It feels very basic and it feels still very like a system just based on the trust that everybody has good intentions.

Kathryn: Absolutely. And to be honest, if you are okay with killing people, you are okay with lying on a poison register, that is a very low bar for people to have to get over in order to acquire arsenic. So I don't think it really hindered anyone. There's also how much it's enforced and checked up on, people could go in and they're like, oh, you look like a reasonable human being who is not about to go and kill someone, even though I don't know you. I'll sell it to you anyway. There weren't really any checks on the people who were selling it or under what circumstances. So it didn't really help much.

Caroline: I scanned through the text of the legislation. I saw that it did include a provision for a fine if anyone was found to be breaking the conditions. But at least in the world of detective fiction, I've never seen anyone be worried about this nor heard any detective figure say, well, at least we can get them on the falsification of the poison book. No one ever says that.

Kathryn: No, absolutely not. And it's quite extraordinary that people, even in the 1890s, so several decades later, they would run occasional checks and they'd send in like children, complete unknowns and just buy arsenic and absolutely no problems whatsoever. Or, oh, don't worry about the poison book, I'll just sell it to you. It was very laissez-faire at the time.

Caroline: So I suppose if it acted as a deterrent at all it only probably deterred the very opportunistic murderer rather than anyone more serious.

Kathryn: Yeah. The person who's just stormed out of their house after a terrible argument and gone, right, I'm going to buy arsenic. And that might be enough of a deterrent. Anyone who's put any kind of serious thought into poisoning someone and has decided it's a good idea, I really don't think it's a hindrance.

Caroline: You mentioned there that notion that they used to occasionally do some sort of consumer cross checks and send people in. That's sort of what we see in Strong Poison by Dorothy L. Sayers, where she has her detective novelist character, Harriet Vane, who is writing a detective novel in which arsenic is going to figure, she tests this out for herself and she discovers exactly as you say that she can go into any shop she likes, give any name she likes and get however much arsenic she wants, which is pretty alarming. Because by this point, we're what, 80 years after the law? Something like that? Nearly.

Kathryn: Easily 80 years. Yeah. And she doesn't appear to be challenged at all. She goes into several establishments. It's not just like the nearest one, and they sort of know her, so they don't check too carefully what name she writes in the register. She does it repeatedly and she takes all of this arsenic home and she's got a nice little stockpile. But it's all just for research, thankfully.

Caroline: Yes, but because that book opens with her on trial for a murder that everyone believes she's done, apart from Peter Wimsey who thinks she's innocent. You can see how that could be taken as a very clear bit of evidence towards guilt that here is someone who has flagrantly breached the law in order to acquire a poison.

Kathryn: Oh, absolutely. And there are certainly real life cases where the purchase of arsenic was traced through the system and it was used as very damning evidence against people who possibly didn't actually do it. They had legitimately bought arsenic and something else had been used to kill whoever it was.

So, yeah, it is damning evidence. I understand why it was brought up in the trial, but it highlights both sides of the law. The fact that it could be used in prosecution very effectively and very persuasively to a jury, but also how easy it was to get around in the first place.

Caroline: And I suppose as well as a reader of a detective novel in 1930 or so, it would seem quite natural that a detective novelist wanted to check a technicality like that. Because what she's planning on putting in her book is technically illegal. So she wants to check, how easy is this to do?

Kathryn: And I do wonder if Dorothy L. Sayers tested it out for herself. But I don't actually know.

Caroline: That's a very interesting point. I don't know that she ever owned up to it if she did, but.

Kathryn: Certainly not. I know she was very thorough in testing of timings and the plausibility of some of her methods and her plots. I wonder if that extended to going to a few pharmacists and seeing if she really could buy arsenic or related compounds.

Caroline: One thing that interests me about this question of buying the arsenic and the poison book and so on is the idea that there are legitimate reasons why you would be buying it. Can you give us some examples of what a legitimate purchase might be for?

Kathryn: I mean, the most obvious legitimate purchase will be as a rat poison, a pesticide. So you've got a problem with, I don't know, bedbugs, flies, whatever, arsenic is a very effective way at killing most living things. So if you use it in appropriate situation, it's very good at getting rid of rats. Or if you soak it into fly papers and hang it up at a window, you can kill off flies.

It was also used in just in an extraordinary number of different products, particularly during the Victorian era. So white arsenic was also used in cosmetics because it was very good at killing bugs and bacteria that caused spots and blemishes. So there were face washes, there were arsenic soaps. And if you knew what you were doing, you could extract the arsenic out of these products.

Or if you weren't of an income that you could afford these kind of name brands, you could buy the cheap fly papers and mix your own face wash. Then of course there's the arsenic dyes, so the green wallpaper, the red candles that were so, so fashionable in the Victorian era. All of that is made from arsenic compounds. It is literally chock-full. The reasons for buying arsenic were numerous and completely believable in almost any circumstance during that period.

Caroline: Which I think is maybe a little bit harder to get our head round today, living in the system of pharmaceutical regulation that we do, and also I think we've now very mentally mostly separated the idea of pesticide from medicine. They're not the same things anymore.

Kathryn: But this is the extraordinary thing that you could buy something that you knew killed a living thing, and know that the same ingredient was in medicines or tonics, pick me ups that were sold and prescribed by doctors. The idea of the dose makes the poison was very, very prominent and you understood that a little bit might not kill you, might give you the appearance of looking better, but a lot of it could be very, very dangerous. But it was very much left up to the consumer to decide what that level was and what risk they were prepared to take.

Caroline: Yeah. That's such an interesting feature to me of all of the regulation that we're talking about today actually, is that the amount of responsibility that's just left up to the consumer, it seems like such a different, almost philosophical way of doing this than we have today.

Kathryn: Absolutely, and you can almost see the light bulb moment in the legislation when they're like, you know what, maybe the consumer isn't the best person to judge the danger associated with this particular product. Maybe we should put that knowledge to experts and we should safeguard it in some way and protect the consumer.

Caroline: Speaking of arsenic being in everything legitimately, that's a very noticeable feature of a book by Anthony Berkeley, The Wychford Poisoning Case, which is actually based on a real life case from the late 1880s, that of Florence Maybrick. And in that case there is too much arsenic. No one can really tell which arsenic killed the victim.

He does have arsenic in him post-mortem, but there's arsenic in medicines. There's arsenic, just neat. His wife who is under heavy suspicion for his murder, she's made a kind of cosmetic, as you say, soaked arsenic out fly papers. There's just too much arsenic everywhere.

Kathryn: Absolutely. And this is exactly how the Florence Maybrick case played out when this very sick man who demanded his special medicine so his wife dutifully gave it to him, after he died and they cleared out the house of all suspected poisons, all of these patent medicines, these pick me ups, these augmenters of your beauty and your attractiveness. The place was absolutely chock full. There were boxes and boxes of stuff that was taken out of this house. Florence Maybrick didn't need to go anywhere to buy more poison, there was plenty in that household. And quite frankly, if she wanted to kill her husband with poison, she did a very poor job of it. She could have speeded things up dramatically if she'd just used his own medicine cabinet.

Caroline: I find that both extraordinary in the real life case, and then the spin that Anthony Berkeley puts on it in that novel is this idea that it's impossible to tell which is the arsenic being applied with malice and which is the arsenic being applied out of care. Because in both cases, I think that the patient is someone who likes to dose themselves, is into patent medicines and they all contain this substance, and so who can say.

Kathryn: Absolutely, and this brought about the, it was called the Styrian Defence. It was a legal defence that was used in arsenic poisoning cases and the accused would stand in the dock and just say, well, you know, they ate arsenic voluntarily. They just ate too much. Nothing to do with me, governor, honest.

And in some cases they got away with it. In some cases, that was genuine and they were accused falsely. So, yeah, it's a really difficult line to take. You would've thought if someone had clearly died of poisoning and you could trace that poison in the body and you found someone who had bought that poison, it would be pretty clear cut, but it really wasn't because of all of this complication around the regulations and just the sheer number of products that you could find these poisons in.

Caroline: Yes. And tell me a bit more about that Styrian defence, cause it's very important to the other novel we've already talked about, Strong Poison.

Kathryn: So the Styrian defence, the idea was in Styria, which is a region of Austria, people chose to eat arsenic. So this is where it all kicked off from. Styria is very mountainous and people working at high altitude, they're doing hard physical labour down in mines. And they said that eating arsenic helped them breathe.

So this was like a legit aid to help them in their work. And it is possible that white arsenic can encourage the production of red blood cells, so you might be carrying more oxygen around your body. It's just not worth the side effects because those side effects were that these guys noticed they started to bulk up a little bit, and so they looked more muscular and they started using it as a beauty aid to attract the opposite sex.

And then the women took it because it gave them fabulous curves. And this was all oedema. This not a good thing. This is an underlying medical condition that you should really get treated for if you have swellings in your limbs or your body. So all of this, they look great. Their complexion was fantastic.

As we've mentioned already, their hair was slick and glossy because arsenic sticks very well to the sulfur in your hair, and so they looked fabulous. It was killing them on the inside, but outwardly they looked great. So this craze spread across Europe and it made it all the way over to the States and beyond.

This is why arsenic started to be put into cosmetic products, face cleansers and soaps and things like that, cause it appeared to be great. So when you are on the witness stand trying to justify why your very rich or very unpleasant spouse suddenly acquired an awful lot of arsenic in their body, well, you know, legit reason, they were very vain. They wanted to look their best and they overdosed.

Caroline: And then there's also this suggestion that Dorothy L. Sayers plays with, which is that this habit of arsenic eating over time, you could build up a tolerance to it, meaning that someone could ingest a fatal dose for somebody else without any side effects. Now I know there's been, science has been back and forward on whether this is even possible, hasn't it?

Kathryn: Yeah, I don't think the way it's played out in Strong Poison would actually work. Do not use this as a blueprint for your own arsenic poisoning because it won't work. The idea that you can take some poison and build up a tolerance to it. There is legit science behind that. It's just that arsenic isn't really one of those poisons.

You might increase the rate at which you excrete arsenic, and so you might be able to take a slightly greater amount, but really it is killing you. And there are parts of the world where people have to ingest arsenic because it's in their groundwater and it does not do them good. It does not build up their immunity to larger doses of arsenic. It kills them.

The other point that Dorothy L. Sayers makes in the novel is that the guy doesn't drink when he's eating his arsenic, and this is actually an important point because they think part of the trick of these famous arsenic eaters who are just shoveling arsenic down their throats, apparently with no side effects, they were using solid arsenic and that would actually pass through the body without being absorbed into the body proper and minimizing the damage.

Whereas if you dissolve it in some kind of liquid, it will get absorbed into the body and it has a greater opportunity to do harm. So there is some science that kind of edges it towards credibility. And I would say that the science at the time that Dorothy L. Sayers was writing, she was spot on. It's just that we know more now about what arsenic is actually doing in the body and it loses its credibility slightly in this building up of a tolerance.

Caroline: It feels a bit too good to be true now, doesn't it, the idea that you can solve the eternal, poisoner's dilemma of how am I going to get you to eat this without eating it myself by actually just eating it yourself but having previously arranged for immunity. It's great in fiction. It's a little bit harder to reconcile in science.

Kathryn: I mean, there are actually signs that he is being affected by the arsenic negatively because he's starting to get damage to his skin. Yes, he's got a clear complexion in that he's got no spots, but he's starting to get patches of discolouration, and that is a sign that he is doing permanent damage to his body through arsenic.

Caroline: After the break: why it's good to know your sugar from your sugar of lead.

Ad music

So that's the Arsenic Act of 1851, which gave us the poison book, which is a favourite motif of golden detective fiction, but doesn't seem to have done very much to keep anybody safe. In the next decade in 1868, the legislators were back at it again with the Pharmacy Act. Can you give us a quick prècis of what was involved in that? What did that do?

Kathryn: So the idea of the Pharmacy Act was that pharmacists wanted a bit more control over who could sell these items. These are people who were training, they had acquired specialist knowledge, and they were in a better position to know what was dangerous and what wasn't, and what should be sold and what couldn't.

So the Pharmacy Act tried to restrict the sale of certain items just to pharmacists so that they would be able to give out appropriate prescriptions or doses or whatever, because before that, yes, there was a poison register, but to be honest, anyone could still sell arsenic, some guy on a street corner, a grocer, you know, anyone could sell arsenic as long as they allegedly recorded that sale in a book. So it wasn't really helping much. So this was just trying to protect the consumer in that you could only get these dangerous things from people who were aware of the dangers. And it's removing that onus of knowing what you're buying from the buyer and putting it onto someone who's had training and has got qualifications.

Caroline: There were, I believe, poisons named in this act that could thus only be sold to registered pharmacists. And there are some names on this list that readers of detective fiction will recognize, but also some that you might expect to be there that aren't.

Kathryn: Oh, absolutely. It is a short list, although some of the categories are quite broad. So there's things like atropine and related alkaloids, and that covers an awful lot of poisons as long as you know what those alkaloids are and that's why you give it to a pharmacist because they will know. But yeah, there's things like, this I had to check because I couldn't believe it was, it wasn't on the list. And that's lead acetate, which crops up in Family Matters. It says very clearly in this novel that this woman had done her homework. She had decided that lead acetate, it was very, very toxic, everyone knew that. And to be honest, they've known lead has been toxic since Roman times. This is not new information, but it isn't on the list of scheduled poisons, so you can just go into a shop and buy as much as you want. No questions asked and no record.

Caroline: And she's even found a semi legitimate recipe for a hair wash that requires it.

Kathryn: Completely legitimate recipe. I, honestly, lead acetate was used in hair dye up until 2015.

Caroline: Goodness me.

Kathryn: Yeah. I think the UK banned it a few years before then, but well into the 20th century, there was still lead acetate in hair dye because it's extremely good. It does dye your hair.

Caroline: I mean that novel Family Matters by Anthony Rolls generally, I think it's great all round, but the chemistry of it is especially enticing, I find, because you've actually got two characters in that book both trying to poison the same person. They've chosen different methods. One, as you say, his wife has picked lead acetate. The other is experimenting with, I think aluminum chlorate and that's his doctor. And so he's taking both these things at the same time. And at least as far as the novelist leads us to believe these two things basically cancel each other out. I'd love to know what you made of this.

Kathryn: There are certainly poisons that cancel each other out. So atropine, a poison I've already mentioned in terms of it was a scheduled poison, you had to sign the register for it. It could only be sold by certain people. Atropine is used as an antidote for other poisonings. So depending on what the poisons are, you keep giving the opposite until you kind of balance everything out.

The idea of using aluminum chlorate as a medicine. Okay, yes, it is interesting. And he says, you know, it's a new method that he's devised and no one would think it was toxic, but in the kind of quantities that he's trying to shovel down this guy's throat, it probably is toxic and he's probably right.

Whether the lead acetate and the aluminum chloride would counteract each other in the way that he says, I'm not so convinced, but in terms of the premise of two poisons counteracting each other totally behind it, yes, that's fine. But the specifics of how those two? Not sure.

Caroline: Well, Dorothy L. Sayers reviewed this book, I think, and there's a quote from her in the introduction to it when she said, you know, I'm not totally sure about the science of this, but I don't care because it works so well in the book. And that's pretty much how I felt reading it.

Kathryn: I would absolutely endorse that recommendation. It's a lovely book simply because it isn't necessarily a murder mystery in that there is a puzzle to solve. The puzzle is when and if they're actually going to kill this guy and who's going to push him across the line. The idea of two people trying to kill someone with opposite effects and them neutralizing... It's a lovely fun read.

Caroline: So this stuff lead acetate that his wife is using, ostensibly for her hair wash actually, to try and kill her husband. As you said, this is not a scheduled poison. No restrictions on who buys it, how much, where you buy it from having to leave your name and address, anything like that. What actually is it?

Kathryn: Lead we are fairly familiar with; it's a metal, you mix it with acetate, which is basically the acidic bit of vinegar, and you get this stuff called lead acetate, which has the wonderful advantage from a poisoner's point of view of it tastes sweet. So, as it says in the book, it is known as Sugar of Lead and has been known by that name since Roman times.

But also the consequences of eating too much of that have also been known since Roman times. So the idea that it wouldn't be listed as a poison when it could be easily mistaken for sugar because again, it's a white powder, just as arsenic is, and you can easily disguise the flavour or make a mistake with it. So it would seem an obvious candidate to be scheduled alongside arsenic for exactly the same reasons as arsenic was 30 years earlier. But it wasn't.

Caroline: Which seems extraordinary, and this is another feature I feel like I've learned from looking into these attempts to regulate poisons over 19th and 20th centuries is just the total inconsistency of even their own rules being applied. Because as you say, the whole matter of colouring arsenic way back in 1851 was all about this, wasn't it?

Kathryn: There were big scandals of arsenic finding its way into sweets and, you kids died as a result. And of course this made a change in the legislation, whereas you could make exactly the same mistake with lead acetate and have the same consequences. It just hadn't happened, so I don't think the government was necessarily aware of it.

Because this legislation isn't made by chemists or pharmacists. It's made by politicians. And unless they have certain cases brought to their attention, they probably aren't aware of the dangers, so you go through the legal cases, the poisoning trials and go, oh, okay, this one, this one, this one. You maybe consult with a pharmacist and they go, yep, they're all bad, put them on the list. But they don't necessarily offer up a whole raft of other stuff that should also be included.

Caroline: That's a really interesting point. I hadn't thought of that, that this is regulation as it's emerged from criminal case law as opposed from science.

Kathryn: And criminal case law in the fact that these accidental poisonings, like this sweet poisoning, there was another case where there was arsenic in beer. These were big public scandals, and under the law at the time, there was nothing they could do because no law had been broken and even I think after the Arsenic Act, laws hadn't necessarily been broken. There wasn't adulteration of food issues that came later, and it was almost a separate tangent of legislation quite apart from this poison register business and Pharmacy Act.

Caroline: So I wanted to turn our attention to another substance that's is, I believe, on the schedule of the 1868 Pharmacy Act, which is strychnine. Now a book that we've discussed before on the podcast, The Mysterious Affair at Styles, is all about strychnine. But the part that I wanted to talk to you about now is not the bit that actually is involved in the death of the murder victim, which is strychnine in a medical tonic, but it's the red herring strychnine that is purchased from the village chemist in order to I guess, draw attention away from the true method of murder. And I suppose here we've got the Harriet Vane problem again, haven't we?

Kathryn: Yeah. But it's being used for the opposite reason. This is a very deliberate red herring. They want people to suspect that this strychnine that was purchased at a particular pharmacy was the strychnine that was used to kill. Because they know as soon as they figure out it's strychnine, they're going to check all the poison registers because it's a scheduled poison.

So they will go round and they will find, oh look, some was bought in the very village where this poisoning occurred, and it was a lethal amount. And, oh, look, the person who bought it looks suspiciously like the young husband of the victim. People are going to put two and two together and make seven because actually it isn't the strychnine that has been used to kill the victim.

And this is the problem. Strychnine is strychnine is strychnine. It doesn't come with a label saying this strychnine was bought as a a rat poison. This  strychnine was bought as a medicine. Once it's inside the body, it's just  strychnine . It is up for a jury to decide how that got into the body and with what intent.

Caroline: You're absolutely right. Yes. There's no way of DNA printing, which chemical is which, right?

Kathryn: Going back to the arsenic case, because of this colouration, if the arsenic that was in the stomach of the victim was coloured, or there were traces of indigo or soot, then yeah, you had an extra tally point with the purchase. But even so, people had stocks of this stuff at home. I don't think you could say, oh yeah, it was that specific packet that ended up in that particular victim.

Caroline: I don't think Sayers really makes a big feature of this in Strong Poison, but I think she does mention that the arsenic that is found in the possession of the murderer just before the end is white arsenic.

Kathryn: It is white arsenic and it's with a French label, so they've had to go abroad to buy it. Presumably, and I haven't checked French law because my French is not up to it, they didn't have to do this colouration, that was a specific to the British law. Even though everyone knew how to remove the vast majority of the colour from their arsenic, I mean, that was common enough knowledge. If you just pop over to France and buy it there, presumably it wasn't an issue.

Caroline: Because that does then make sense with the method of delivery in that book, which is, it's whisked into an omelet. You would notice if your omelet was a bit purple.

Kathryn: Oh, definitely, definitely. All of those little warning signs, like the bitter taste, the strange colour, the food that doesn't look right. Yeah. That's all going to warn your victim, don't eat this. That's why arsenic was so popular because it just looked like sugar.

Caroline: And just going back to the strychnine for a second, and The Mysterious Affair at Styles, I suppose something that I get from that book, which is part of Christie's genius, you know, she was her very first novel and yet she's doing this. She's demonstrating how the poison book system can be turned to the benefit of a murderer rather than it being about regulation, it's actually about deceit.

Kathryn: This is how she's so great in so many of her novels. Something that you would think would be a disadvantage to a poisoner, she can twist it to an advantage, certainly in terms of her plot, be cause it's almost a double red herring. The idea is they want this particular person to be tried because at the time they had double jeopardy and they want this person to be acquitted so that they can get away with it, but they're not going to be acquitted because obviously there's a retired Belgian detective on the scene.

She does it again, and then again and again especially with poisons, things that you think, well, no, that's too obvious. You can't do that. But she always finds a little twist so that she can keep her readers guessing.

Caroline: It's fascinating as well to think by 1920 how familiar the general public was with this system of you want to buy some arsenic, some strychnine, you write your name in the book that you could. Put that in a novel as quite a complex plot point, and everyone would know exactly what you meant.

Kathryn: Exactly, and I think as modern readers, because we don't have that background knowledge because we can't just walk into a pharmacy and expect to buy  strychnine, no matter what the reason behind it, they're not going to sell it to you. They haven't got it in stock.

It just never occurs to us. It's quite a common mistake, I think, to hear the phrase "poison book" and think about like a reference textbook, where someone's learnt about poisons. No, this is the poison book that's kept in the shop with people's names and addresses and yeah, that you can just drop this as shorthand into your novel or short story and everyone will go, oh yeah, okay. Got that. Moving on. Without any need for explanation. I think going back to it with a bit of knowledge about poison registers and rereading some of this stuff, you appreciate how conscious the writers were at the time of what they needed to say and what they carefully left out because they knew their audience would make assumptions.

Caroline: Moving on to the third of our three major laws that we're looking at today. This is the Dangerous Drugs Act of 1920. So this is a golden age era attempt to regulate poisons and drugs. What did this one involve?

Kathryn: So this more or less just added some more stuff to the list of things that had to be regulated when it came to point of sale, and it included some things that you would've thought would automatically just be on the list. So, morphine, heroin, cocaine. Things that have become street drugs rather than prescription drugs. So all of this stuff was beforehand, you could get hold of it, no problem. No questions asked. It was a medical condition, a failure of character that you are addicted to this stuff. But you weren't a criminal. But as soon as the 1920 law was passed, the purchase of things like cocaine and heroin became illegal. And so you became a criminal rather than someone who was just an addict.

Caroline: So this one doesn't have quite so much resonance to detective fiction, really, because sometimes we see morphine, but not so much the other drugs.

Kathryn: Christie makes a few references to cocaine in her novels, but it is always as someone is an addict. And it is a sign of their lack of moral fibre or whatever it might be. It's a hint that they're wrong'un. Morphine is used a bit, but only in a medical context, really. She's a bit vague on her street drugs. But no, it doesn't really crop up in a lot of other murder mysteries except in the context of, oh, they're an addict. Maybe they took too much. Maybe they were deliberately given an overdose knowing that they had a limit.

Caroline: What also interests me about the Dangerous Drugs Act of 1920 is that it doesn't seem, as far as I understand it, to take the opportunity to correct any of the problems arising from the previous laws. So all of the things we've been talking about, about how easy it was to falsify the poison book, or just hoodwink pharmacist, or just buy things under a different name or just buy things that weren't mentioned. Didn't really bother to fix that.

Kathryn: No, because in theory, if the law was actually enforced as intended and that the people selling the stuff really did have to know the person or if they didn't have to have a prescription or very good written reason from an expert to buy it, then it should have reduced the opportunities, but it just wasn't enforced. So maybe they didn't feel that they needed to correct it because they never actually thought maybe we just shouldn't sell this at all. A lot of that came in much, much later. It's quite astonishing what was still available for sale. Even if it fell out of fashion and it wasn't used as much, you could still get hold of it. It would just look a bit more suspicious if you went into a shop in the 1950s and asked for some arsenic. I think questions would be asked in the 1950s, not so much in the 1920s and 30s.

Caroline: So all of these laws and the, I suppose, the kind of culture that had grown around them by the time we get to the interwar period when a lot of detective fiction is being written, this is 70-year-old legislation that, as you say, never really been properly enforced. Um. And that's what everybody's working with. I think if I was going to draw any conclusion from, what I've learned from working with you on this is that a lot of this regulation seems, even despite the attempts to the contrary, seems to be after the fact.

It's about, after you've bought the poison, please just write your name in this book. Not, you can't buy this poison in the first place, that it's all very post hoc.

Kathryn: Absolutely. And today I would say it would be very different. For example, I wouldn't want to test out the limits of the current legislation, but if you just phone up a chemical company and start asking for certain things that are dubious and you are not giving a university chemistry lab as the delivery address, I think they're going to ask questions. They're not necessarily going to sell it to you. You certainly won't be able to just go to the corner shop and buy this stuff or get it on Amazon. There are regulations about the sale of certain things and even innocuous things that in combination can produce dangerous substances or illegal substances.

Those kind of Google searches, those are monitored. And they get flagged. So there is an awful lot of preventing this stuff getting into potentially the wrong hands in the first place. And that was very much not the case a hundred years ago.

Caroline: Which is to the benefit of our detective fiction perhaps, and absolutely not to the benefit of anyone in real life who came into contact with any of these substances.

Kathryn: Absolutely.

Music

This episode of Shedunnit was written, produced and narrated by me, Caroline Crampton. Many thanks to my guest, Dr Kathryn Harkup. You can find out more about her and her books at her website, harkup.co.uk.

You can find a full list of the books and sources used in the making in this episode at shedunnitshow.com/thepoisonbook. I publish transcripts of every episode including this one; find them all at shedunnitshow.com/transcripts.

If you'd like to stay in touch with the podcast in between episodes, subscribe to the Shedunnit newsletter at shedunnitshow.com/newsletter. We're not updating social media anymore, so that is the best and only place to know what we're working on next.

Shedunnit is edited by Euan McAleece. Production assistance and research for this episode from Leandra Griffith. Member support for the Shedunnit Book Club from CC McLoughlin.

Thanks for listening.