“If he used rubber to self-seal them, won’t that show up in your tests?”
Moller grimaced. “I’d like to give you an emphatic yes to that question, because we reckon we can detect the faintest trace of any substance. And so we can, as long as we can get at it in situ. But as I told you, we’ve got to cleanse those tins before we can inspect them as carefully as we would need to to find a minute plug of rubber.”
“You mean the rubber could be washed away?”
“Or melted or jogged out as we straighten those coils of tin. Dammit, it could have been dislodged in the act of opening the tin in the first place. Tearing that metal tape away isn’t exactly a gentle business, you know. That’s point one.”
“There are others?”
“Yes. I don’t want to detract from Sergeant Berger’s bright idea, but you have to remember that injection needles are hollow. Pushing them through blobs of rubber could bung them up.”
“In that case the injection would fail?”
“Not necessarily. But it could mean that more force would have to be put behind the plunger to clear the blockage and force the contaminated broth into the tin.”
“Because he had to exert more pressure he would lose some of his control and thus spoil the shot?”
“Either that or he could over-inject. I’m certain he would over-fill his syringe with broth just to cut out the chance of injecting air. So, if the plug were to give way suddenly, before he could stop himself he may have injected more than enough. In that case, the contents of the tin could exert pressure from inside and, when the needle was withdrawn, could start to ooze out through the hole. This would preclude the rubber preparation from forming a bung. Instead, the juices themselves would coagulate and seal the hole. If this happened, there would be no rubber for us to find.”
“I see. But the contamination would have been a success?”
“Of course. And if the chap responsible was clever enough to add gelatine to the broth and followed the drill I have just described, that would be likely to be even more successful.”
“Still using the blob of rubber?”
“Certainly. He’d have to prevent the initial inrush of air.”
“It’s all bloody complicated,” said Green.
“To a layman, perhaps. But not to someone like me or anybody who worked in a laboratory. We’re used to doing fine, fiddly jobs like that.”
Green glanced across at Masters. “He’s made your point for you, George.”
“What point is that?” asked Moller.
“When we left the Yard last night, His Nibs said we would be looking for a chemist clever enough to culture botulism who would, at the same time, be a good enough laboratory technician to get it into the tins.”
“On the face of it, that would seem a reasonable supposition.”
“What would?” asked a new voice from the door. As one, they all swung round to face the newcomer. It was Convamore. The pathologist came over to join them. He pushed one of the contaminated tins aside, unceremoniously for such an object, and hefted himself up to sit on the bench.
“Getting anywhere?” he asked Masters.
“That remains to be seen. We’ve discussed with Dr Moller the method by which we think the contamination could have been introduced into the tins in an inconspicuous manner.”
“Oh? What method is that?”
Convamore listened to the explanation and appeared impressed by it. He went further and said that he himself could certainly suggest nothing more likely though, for form’s sake, he thought they must investigate the way the Redcoke depots handled goods to see whether one of them was, in some obscure way, contaminated and, at the same time, capable of transferring such contamination from one set of canned goods to another. “It is highly improbable,” he confessed, “but just for laughs we must ascertain whether all these tins did, in fact, pass through the same depot at the same time.”
Green grunted his approval of the logic behind this, but said he doubted the usefulness of such a line of enquiry.
“How do you see it then?” asked Convamore.
“Jiggery-pokery,” said Green. “We’ve got a nutter here, but he’s a clever bastard, nonetheless. Not only as far as his knowledge of bugs and his technical laboratory ability are concerned, either. He’s a conjurer, too. I reckon he buys his tins and doctors ’em. Buys them quite openly, that is, passing through the check points like any other customer. Then he goes on another shopping spree . . .”
“Not necessarily to the same supermarket,” said Reed.
“Right, lad. But when he goes into a Redcoke store, he has a doctored tin with him. Easy enough to do—in a shopping bag. Then he swaps his tin for another of the same sort, or just leaves it. People ditter about like that in supermarkets all the time. They choose goods, then change their minds and put them back and pick up something else. And he can’t be nabbed by store detectives—not unless he goes outside with something he hasn’t paid for.”
“As simple as that, you think?”
“The simpler the better.”
“But he gets about—Somerset, Essex, Derby.”
“Right, Professor. That makes it difficult for us. He could buy the goods here in London, for all we know. But he doesn’t dump them back in the same shop. He travels.”
“And that,” said Masters, “is a headache for us. There’s no anchor point round which we can centre our investigation. We would be looking for a man from any town or village in the country. Had he concentrated his efforts all in one area, we could comb that district for leads. But we haven’t got that advantage.”
Convamore shrugged. “My job’s easier, thank heaven.” He turned to Moller. “My body specimens haven’t arrived yet, so I’m held up for an hour or two. I shall then be starting saprophytic cultures. I suppose yours are already under way.”
“Saprophytic?” queried Masters.
“Sorry. A saprophyte is an organism—like the clostridium bacillus—which lives on dead organic matter.”
“Dead?”
“Yes, dead, in so far as all the meat you live on is dead—with the possible exception of oysters, if you ever take them.”
“You are culturing the botulism bacteria?” asked Reed.
“We have to, Sergeant, to see if that’s what we’ve got.”
“I understand that, sir. But our man—will he know how to do that?”
“Don’t ask me.”
“Then could I ask you, sir,” said Reed, reddening at his own temerity, but determined to show Masters that he was taking an active and intelligent interest in the minutiae of the case, “could I ask you how you culture the . . . saprophytes? So that we know what the bloke we’re looking for would have to know?”
“The pleasure’s ours,” said Convamore. “Mine and Moller’s. If you reckon it will help you, we’re not going to hold back—certainly not when we get a chance to gas about our own specialities.”
“Keep it simple, please,” urged Masters.
“The basis of most artificial culture media is nutrient broth,” said Convamore. “Broth is broth. Ours is a solution of meat extract. We pep it up a bit to make it better and quicker for our purposes by adding a derived protein and making the whole thing neutral—that is neither salty nor acid. We then add agar, which is an abstraction from Japanese seaweed. It is, chemically, a polysaccharide, and if you want to know what they are, well . . . cellulose and starch are good everyday examples. This helps the broth to solidify more easily on a petri dish or a glass slide. But even better is blood agar. Sounds ghastly, but you know how good the gravy is when you cut a decent joint of beef roasted rare. We use a little horse blood.”
“And the bugs thrive on this?”
“Or something like it. I’m going to put cooked and minced beef heart into my nutrient broth. It just happens that organisms of the genus Clostridia like it!” He turned to Moller. “Are you using Robertson’s meat medium, too?”
Moller nodded. “In a Mcintosh and Fiddes
jar and in one of the new jars for comparison.”
Convamore turned to Masters. “The jar you’ve just heard about is, these days, an aluminium cylinder which holds several petri dishes with blood agar plates and so on. It’s specially made for the culturing of anaerobic organisms. It has an airtight lid with two stop cocks. To one we attach a pump and suck out the air, and to the other we attach a cylinder of hydrogen. The gas enters the jar under pressure and replaces the air. But just to make sure conditions are anaerobic, on the underside of the lid of the jar is a little electric coil which heats some palladium asbestos . . .”
“Palladium being the hard white metal?”
“That’s right. It belongs to the platinum group. The palladium asbestos—when heated—acts as a catalyst to cause any little bit of oxygen remaining in the jar to react with the hydrogen to form water. Hey presto! Anaerobic conditions for the little beauties to multiply in.”
“And Dr Moller’s new jar? What’s that like?”
“Much simpler,” said Moller. “It has a catalyst that works at room temperature and uses disposable packs of hydrogen. There’s no need for gas cylinders and vacuum pumps.”
“That’s good,” said Reed.
“What is?” asked Moller, in some amazement.
“Well, sir, the chap we’re looking for will have to do all this culture business himself, won’t he? If it’s a tricky job with a Mac Something or other’s jar . . .”
“No, no,” said Masters. “I think you’ve misunderstood. Professor Convamore and Dr Moller are testing the body organs and the meat cans to see if botulism is actually there. To prove it they have to culture any botulism bacteria which are already in the body fluids—vomit mainly—and the inside scrapings of the tins, to see, first, if botulism is present in both and then to see if the types are the same. That establishes that botulism is the disease, and that it definitely came from these cans. But the man who injected the cans wouldn’t have the tricky business of culturing anything in the ways we’ve just heard.”
“No, Chief?”
“Think, Sergeant! Where would he get the material to culture? No, he has to produce his own botulism and from what I can gather, that’s the easiest thing in the world, and some people do it by mistake.”
“You must be joking, Chief.”
“Not at all,” said Convamore. “Clostridia are everywhere. When you can meat or vegetables, you have to heat the doings for a long time at a high temperature to kill the spores. But if you can or bottle something and don’t heat it for very long and keep the temperature fairly low, you know as well as I do you’re asking for trouble. I reckon if you were to put a bit of soil into your cooking, you’d be certain to produce botulism in the stew. And there it is, all ready to be syphoned off and injected into tins of bully, ham and luncheon meat.”
Reed scratched his head. Green, seeing his predicament, came to his rescue. “Never mind, lad! Have a fag.”
“In here?”
“Why not? I’m sure the boffins won’t mind us having a drag while we get a bit more out of them. I’m all at sea myself, you see. So, no doubt, they’ll put us right.”
“I’d prefer you to come into the office if you want to smoke,” said Moller. “Particularly if the Professor is going to light up one of his cigars. All our readings would be shot to hell with everybody puffing away in here.”
Convamore dropped from the bench to his feet. “And a cup of coffee, perhaps, young Moller? Or because you’re government-employed do you get nothing but tea?”
Moller grinned. “I’ve educated them round here. We’ve built our own coffee maker. It’s surprising how efficient a brew-machine one can make with a couple of flasks, a funnel, glass tubing, filter papers and a bunsen burner.” He turned to Green. “We use beakers, too—the laboratory sort—to drink out of, if there are more people than we have cups for. They’re quite good if you hold them in your handkerchief.”
“Doesn’t worry me, doc. In the desert I had to wire an old tin lid over my mug to keep the flies out of the char. If you’ve coped with that for a couple of years you can cope with anything.”
“I did that,” said Convamore. “But I cut my nose on the tin lid and got a desert sore—right on the end of my hooter. Can openers weren’t as efficient in those days. They tended to leave jagged edges.”
As they moved to Moller’s office—one of a number which led off the laboratory—Masters said quietly to the forensic scientist: “They’re off. Get together two old boys who served in the desert and you might as well write off the rest of the morning.”
“Don’t worry. We’ll dish up the coffee and then I’ll interrupt the reminiscences. We none of us have enough time to fight an old war over again. We’ve got enough on our hands with the present battle against botulism.”
“Thanks.”
“Convamore won’t mind. He’ll be as happy giving you a lecture on pathogenic bacteria as he will discussing the battle of Alamein.” He ushered Masters through the office door. “Everybody take a pew where they can. Perhaps one of the sergeants would bring in a couple of bench stools.”
Less than five minutes later, Moller had managed to steer the Professor back to the reason for the meeting.
Convamore puffed happily at his cigar and began. “Pathogenic bacteria are those that enter the body tissues to live as parasites and cause disease. Most of them invade the tissues—that is they actually burrow into the flesh or muscle or gut or whatever—and cause inflammation. These little blighters contain certain substances known as endotoxins which help them to invade the body tissues. But there are a few bacteria—some of which invade tissues and some of which don’t—which have within themselves extremely powerful poisons known as exotoxins.”
“Like poisonous snakes?” asked Masters.
“Exactly. The bacteria with endotoxins can be likened to snakes which will give you a nasty bite but which won’t kill you; while those with exotoxins are the ones with a poison that could kill you off pretty quickly if you weren’t given an immediate antidote. Good simile, Mr Masters.”
Masters inclined his head to acknowledge the compliment. The Professor waved his cigar in the air before beginning again.
“Fortunately, the list of diseases caused by these exotoxins is small. Diphtheria is one—that used to be a killer—scarlet fever another, tetanus another and gas gangrene—the one which caused so many fatalities among wounded men in trench warfare yet another. And that . . .” he took another long draw on his cigar, “. . . brings us to the subject of our present investigation, Clostridium botulinum, which little bastard can be absorbed into the tissues through intact intestinal wall to produce botulism.” He turned to Green. “Are you with me so far, DCI?”
“I’m getting there,” grunted Green.
“What isn’t clear?”
“It’s clear enough.”
“You’re sure?”
“Would you like me to recite it back to you?”
Masters interrupted. “We’ve understood it, Professor. Whether we’ll remember it all is a different matter.”
“Quite. But as long as you get the salient points and the general drift . . .”
“We’ll manage that.”
“Excellent. Now, the bacteria themselves. Seen under a very high powered electron microscope, they appear as little rod-shaped bodies with flagella which, as you no doubt know from your police encounters with flagellation, are little whip-like hairs which provide their means of locomotion. The only other thing you need know about them is their peculiar reproductive habits.
“They are primitive micro-organisms and reproduce by binary fission. That means they grow bigger and then split into two. Under favourable conditions, division may be repeated every half hour, so that in less than a day a single organism may become a thousand million. That is not what I meant by peculiar. The next bit is. Under unfavourable conditions a certain number of bacteria form endospores. That’s more like a hen developing an egg within itself, because the bacterium
does not divide but forms the spore inside its own cell. The spore—like an egg—develops a thick covering layer called a cortex . . .”
“Like the brain of a human?” asked Masters. “A cerebral cortex?”
“Bang on,” said the Professor. “A cortex and then a thin but very tough spore coat. As a result, the spores are very resistant to heat. So, though the original bacterium may be killed off by heating to sixty degrees centigrade, the spore will live on, despite its parent’s death, until it has been subjected to moist heat at about a hundred and twenty centigrade for ten minutes or more. If it isn’t killed off by heating, and the spore finds itself in a favourable environment, it will germinate to form daughter bacteria which soon begin, once more, to divide in the normal way by binary fission. And that, gentlemen, is the story of its life cycle.”
“Let me get this straight,” said Green. “When it is in soil, that is the unfavourable environment in which it forms spores. When it gets among the meat and veg, that is the favourable environment which makes it reproduce like the clappers.”
“I couldn’t have put it better myself.”
“And these poisons—exotoxins—actually cause a form of intoxication.”
“Right. Bacterial intoxication. Where the more popular form of booze-up will cause all the nasties everybody knows about—sickness, loss of co-ordination, double-vision, headache and a hangover—bacterial intoxication from botulism causes vomiting, ocular palsy and throat paralysis. It attacks the nervous system in other words, and all we can do is to inject an anti-serum and provide life support measures for the victims. We hope that these measures will be successful in fifty per cent of patients.”
“What serum is it?” asked Masters.
“A polyvalent horse serum. It has to be polyvalent, because we never know which type of botulism is involved. As you were told last night, there are types A to F and each type produces its own exotoxin. Unfortunately, immunity to one will not protect a human from any of the others, and the bloody exotoxin they each produce will pass through a man’s intestinal wall like nobody’s business. If you want to see how fast the stuff works, visit my lab this afternoon. I shall be injecting mice with blood serum from the affected patients. I’ve got to do it to make absolutely sure—apart from the symptoms—that the diagnosis of botulism is the correct one. I expect those mice to die of the disease in three or four hours.”
The Longest Pleasure Page 5