“I don’t understand this at all,” he said. “I shall have to make a more thorough examination than is possible while he is lying in this position. I’m afraid there’s nothing to be done. I don’t want to move him until your Inspector comes. He won’t be long, I suppose?”
“He’s living close to the station,” replied the detective. “They’ve sent a man with a motorcycle and sidecar round to fetch him and bring him here. It oughtn’t to take him more than a few minutes. I’d rather you waited, if you don’t mind.”
The doctor nodded and continued his examination, while the other three stood where they were, looking keenly about them. It was obvious that when death overtook Mr. Copperdock he had been preparing for bed. His coat, waistcoat, shirt and vest lay on a chair, and the basin on the washing stand was half full of soapy water. A towel lay on the floor near it.
The minutes seemed to pass with leaden slowness until a faint throbbing reached their ears, which rapidly grew in intensity until it resolved itself into the sound of a motorcycle. The noise ceased suddenly as it reached the door, and in a few seconds Inspector Whyland appeared, half dressed, with a stern expression on his face.
“How did this happen, Waters?” he enquired sharply, turning to the detective.
“I don’t know, sir,” replied the latter. “I’ve been watching the house all the evening—”
“Well, never mind, you can tell me about that later,” interrupted Whyland. “Good evening, doctor. Can you tell me what this man died of?”
“No, I can’t” replied the doctor. “It looks as if he had been bitten by a snake, or something of that kind. I was waiting till you came to make a thorough examination.”
“Right. Stand fast a minute while I look round.” He made a swift survey of the room, then, taking a piece of chalk from his pocket, marked on the carpet the position in which the body was lying.
“Now then, doctor, I’m ready,” he said. “What do you want to do?”
“I want him laid on his side, if you’ll bear a hand,” replied the doctor. “That’s right. Hullo, look at that!”
They had moved Mr. Copperdock’s body until his back was visible. There, just below the left shoulder-blade, was an almost circular patch, covered with a curious white powdery incrustation. In the centre of this patch was an angry looking purple spot.
The doctor bent over this and uttered an exclamation of amazement. Opening the case which he had laid down by his side he took from it a pair of forceps, and applied them to the spot on Mr. Copperdock’s back. From this he withdrew something, which he carried over to the light, and beckoned to Whyland to inspect.
“See that?” he said. “That’s the end of a fine hypodermic needle. I’m beginning to see what happened, now. He was injected with some powerful toxic agent by means of a hypodermic syringe, the needle of which broke off in the process. The nature of the poison we shall be able to determine by an examination of this fragment. But I don’t understand that white incrustation. Let me have another look at it.”
He selected a small phial from his case, put the fragment of the needle into it, and labelled it. Then he turned once more to Mr. Copperdock’s body, and examined the patch once more with a lens. Finally he removed some of the white powder and put it in another phial, which he also sealed and labelled.
Then he beckoned Whyland aside, and the two conversed for a moment in low whispers.
“This is really most extraordinary,” said the doctor. “This man undoubtedly died from an injection of poison administered hypodermically. You remember the case of Colburn, the baker, last year?”
“Yes, I remember it well,” replied Whyland. “What about it, doctor?”
“Well, of course, I can’t say definitely as yet,” replied the doctor guardedly. “But it seems to me that the symptoms in the two cases are remarkably similar. I would go so far as to hazard the opinion that the same poison was employed in both cases. Now, in the present case, you, I take it, are chiefly interested in the agency by which the poison was administered. Well, it is possible that in this case it was self-administered. One can just manage to run a hypodermic needle into oneself below the left shoulder-blade. Here’s a syringe. There’s no needle in it. Hold it in your left hand. That’s right. Now, see if you can press the nozzle against your back in the place corresponding to the spot on Mr. Copperdock’s body.”
Whyland obeyed, and after some fumbling contrived to reach the exact spot. “Yes, it can be done, but it’s precious awkward,” he remarked, handing the syringe back.
“Exactly,” agreed the doctor. “That may account for the needle having broken off. Mind, I’m only suggesting a possibility, not laying down a theory. That’s your job. Now we come to the white incrustation round the puncture. Unless I’m greatly mistaken, it is potassium carbonate. Should it prove to be so, the fact would be of considerable significance.”
“Why?” enquired Whyland. “I’m afraid I don’t quite follow you, doctor.”
“Potassium carbonate has no particular properties of its own,” replied the doctor. “But, if a piece of caustic potash had been applied to the puncture, say an hour or two ago, it would by now have been converted into potassium carbonate. You see what this suggests. Caustic substances are employed to burn out poisoned surfaces. In this case, caustic potash may have been employed in an attempt to counteract the poison. Of course, it would be ineffectual, as it had been injected far too deeply. But that it has been so applied I am pretty certain. You can see for yourself that the skin shows traces of burning under the incrustation. Whether the same hand that injected the poison applied this ineffectual antidote, I cannot say.”
Whyland nodded, and then
