“As for Teresa de Leon, it was jealousy that impelled her to follow Jose Barrios from Cuba to New York.  The murderer, in his scheming, knew it, saw a chance to use her, to encourage her, perhaps throw suspicion on her, if necessary.  When I came uncomfortably close to him he even sent an anonymous telegram that might point toward her.  It was sent by the same person who stole in Barrios’s office and shot him with an asphyxiating pistol which discharged a fatal quantity of pure veratrine full at him.

“My love meter, in registering hidden emotions, supplements what the polarimeter tells me.  It was the levo-rotary veratrine of the fatal death camas which you used, Page,” concluded Craig, as again the electric attachment clicked shut the lock on the laboratory door.

VIII

THE VITAL PRINCIPLE

“That’s the handwriting of a woman—­a jealous woman,” remarked Kennedy, handing to me a dainty note on plain paper which had come in the morning mail.

     I did not stop to study the writing, for the contents of the
     letter were more fascinating than even Kennedy’s new science
     of graphology.

     You don’t know me [the note read], but I know of your work
     of scientific investigation.

     Let me inform you of something that ought to interest you.

     In the Forum Apartments you will find that there is some
     strange disease affecting the Wardlaw family.  It is a queer
     disease of the nerves.  One is dead.  Others are dying.

     Look into it.

     A friend.

As I read it I asked myself vainly what it could mean.  There was no direct accusation against any one, yet the implication was plain.  A woman had been moved by one of the primal passions to betray—­some one.

I looked up from the note on the table at Craig.  He was still studying the handwriting.

“It’s that peculiar vertical, angular hand affected by many women,” he commented, half to himself.  “Even at a glance you can see that it’s written hastily, as if under the stress of excitement and sudden resolution.  You’ll notice how those capitals—­” The laboratory door opened, interrupting him.

“Hello, Kennedy,” greeted Doctor Leslie, our friend, the coroner’s physician, who had recently been appointed Health Commissioner of the city.

It was the first time we had seen him since the appointment and we hastened to congratulate him.  He thanked us absently, and it was evident that there was something on his mind, some problem which, in his new office, he felt that he must solve if for no other purpose than to justify his reputation.  Craig said nothing, preferring to let the commissioner come to the point in his own way.

“Do you know, Kennedy,” he said, at length, turning in his chair and facing us, “I believe we have found one of the strangest cases in the history of the department.”