Appointment with Death by Agatha Christie Page B

of the time death had occurred?”
    The Frenchman shrugged his shoulders. “It is difficult to be exact after that length of
     time. There must necessarily be a margin of several hours. Were I giving evidence on oath
     I could only say that she had been dead certainly twelve hours and not longer than
     eighteen. You see, that does not help at all!”
    “Go on, Gerard,” said Colonel Carbury. “Give him the rest of it.”
    “On getting up in the morning,” said Dr. Gerard, “I found my hypodermic syringe - it was
     behind a case of bottles on my dressing table.” He leaned forward. “You may say, if you
     like, that I had overlooked it the day before. I was in a miserable state of fever and
     wretchedness, shaking from head to foot, and how often does one look for a thing that is
     there all the time and yet be unable to find it! I can only say that I am quite positive
     the syringe was not there then.”
    “There's something more still,” said Carburv. “Yes, two facts for what they are worth and
     they mean a great deal. There was a mark on the dead woman's wrist - a mark such as would
     be caused by the insertion of a hypodermic syringe. Her daughter explains it as having
     been caused by the prick of a pin - ”
    Poirot stirred. “Which daughter?”
    “Her daughter, Carol.”
    “Yes, continue, I pray you.”
    “And there is the last fact. Happening to examine my little case of drugs I noticed that
     my stock of digitoxin was very much diminished.”
    “Digitoxin,” said Poirot, “is a heart poison, is it not?”
    “Yes. It is obtained from digitalis purpurea - the common foxglove. There are four active
     principles - digitalin - digitonin - digitalein - and digitoxin. Of these, digitoxin is
     considered the most active poisonous constituent of digitalis leaves. According to Kopp's
     experiments, it is from six to ten times stronger than digitalin or digitalein. It is
     official in France - but not in the British Pharmacopoeia.”
    “And a large dose of digitoxin?”
    Dr. Gerard said gravely: “A large dose of digitoxin thrown suddenly on the circulation by
     intravenous injection would cause sudden death by quick palsy of the heart. It has been
     estimated that four milligrams might prove fatal to an adult man.”
    “And Mrs. Boynton already suffered with heart trouble?”
    “Yes; as a matter of fact, she was actually taking a medicine containing digitalis.”
    “That,” said Poirot, “is extremely interesting.”
    “D'you mean,” asked Colonel Carbury, “that her death might have been attributed to an
     overdose of her own medicine?”
    “That - yes. But I meant more than that. In some senses,” said Dr. Gerard, “digitalis may
     be considered a cumulative drug. Moreover, as regards postmortem appearance, the active
     principles of the digitalis may destroy life and leave no appreciative sign.”
    Poirot nodded slow appreciation. “Yes, that is clever - very clever. Almost impossible to
     prove satisfactorily to a jury. Ah, but let me tell you, gentlemen, if this is a murder,
     it is a very clever murder! The hypodermic replaced, the poison employed being one which
     the victim was already taking - the possibilities of a mistake - or accident - are
     overwhelming. Oh, yes, there are brains here. There is thought - care - genius.”
    For a moment he sat in silence, then he raised his head. “And yet, one thing puzzles me.”
    “What is that?”
    “The theft of the hypodermic syringe.”
    “It was taken,” said Dr. Gerard quickly.
    “Taken - and returned?”
    “Yes.”
    “Odd,” said Poirot. “Very odd. Otherwise everything fits so well...”
    Colonel Carbury looked at him curiously. “Well?” he said. “What's your expert opinion? Was
     it murder - or wasn't it?”
    Poirot held up a hand. “One moment. We have not yet arrived at that point. There is still
     some evidence to consider.”
    “What evidence? You've had it all.”
    “Ah! But this is