The doctor inclined his head towards Fullaway, and added a grave bow in answer to Allerdyke’s question.

“The autopsy has been made,” he replied.  “By Dr. Lydenberg, Dr. Quillet, who is one of the police-surgeons here, and myself.  We made a very careful and particular examination.”

“And—­the result?” asked Allerdyke eagerly.  “Is it what you anticipated from your first glance at him—­here?”

The doctor’s face became a shade graver; his voice assumed an oracular tone.

“My two colleagues,” he said, “agreed that your cousin’s death resulted from heart failure which arose from what we may call ordinary causes.  There is no need for me to go into details—­it is quite sufficient to say that they are abundantly justified in coming to the conclusion at which they have arrived:  it is quite certain that your cousin’s heart had recently become seriously affected.  But as regards myself”—­here he paused, and looking narrowly from one to the other of his two hearers, he sank his voice to a lower, more confidential tone—­“as regards myself, I am not quite so certain as Dr. Lydenberg and Dr. Quillet appear to be.  The fact of the case is, I think it very possible that Mr. James Allerdyke was—­poisoned.”

Neither of the two who listened so intently made any reply to this significant announcement.  Instead they kept their eyes intently fixed on the doctor’s grave face; then they slowly turned from him to each other, exchanging glances.  And after a pause the doctor went on, speaking in measured and solemn accents.

“There is no need, either, at present—­only at present—­that I should tell you why I think that,” he continued.  “I may be wrong—­my two colleagues are inclined to think I am wrong.  But they quite agree with me that it will be proper to preserve certain organs—­you understand?—­for further examination by, say, the Home Office analyst, who is always, of course, a famous pathological expert.  That will be done—­in fact, we have already sealed up what we wish to be further examined.  But”—­he paused again, shaking his head more solemnly than ever—­“the truth is, gentlemen,” he went on at last, “I am doubtful if even that analysis and examination will reveal anything.  If my suspicions are correct—­and perhaps I ought to call them mere notions, theories, ideas, rather than suspicions—­but, at any rate, if there is anything in the vague thoughts which I have, no trace of any poison will be found—­and yet your cousin may have been poisoned, all the same.”

“Secretly!” exclaimed Fullaway.

Dr. Orwin gave the American a sharp glance which indicated that he realized Fullaway’s understanding of what he had just said.

“Precisely,” he answered.  “There are poisons—­known to experts—­which will destroy life almost to a given minute, and of which the most skilful pathologist and expert will not be able to find a single trace.  Now, please, understand my position—­I say, it is quite possible, quite likely, quite in accordance with what I have seen, that this unfortunate gentleman died of heart failure brought about by even such an ordinary exertion as his stooping forward to untie his shoe-lace, but—­I also think it likely that his death resulted from poison, subtly and cunningly administered, probably not very long before his death took place.  And if I only knew—­”